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International Journal of Surgery xxx (2014) 1e4
Contents lists available at ScienceDirect
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Original research
A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy Q3
Ron Lavy a,1, Yehuda Hershkovitz a,1, Andronik Kapiev a,1, Bar Chikman a,1, Zahar Shapira a,1, Natan Poluksht a,1, Nirit Yarom b,1, Judith Sandbank c,1, Ariel Halevy a, *,1 a b c
Division of Surgery, Assaf Harofeh Medical Center, Zerifin 70300, Israel Institute of Oncology, Assaf Harofeh Medical Center, Zerifin, Israel Institute of Pathology, Assaf Harofeh Medical Center, Zerifin, Israel
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 February 2014 Received in revised form 24 April 2014 Accepted 9 May 2014 Available online xxx
Background: The number of lymph nodes harvested during gastrectomy depends on the extension of lymphadenectomy and the method of lymph node retrieval. Aim: The objective of this study was to evaluate two methods of lymph node retrieval in specimens of gastric cancer. Methods: The number of lymph nodes was compared using two different techniques. The technique used in the first group was manual dissection following formalin fixation, and the techniques used in the second group was fat-clearing by acetone. Results: Both groups were comparable for demographic and pathological variables. The average number of harvested nodes was 19.3 10 for the manual group as compared to 26.1 14 in the acetone group (P ¼ 0.003). The differences in the average number of positive nodes did not reach statistical significance (4.6 compared to 6.9 nodes). Conclusion: The acetone clearing technique enables the evaluation of a larger number of nodes. An increase, but statistically non significant, number of positive nodes was noted in the acetone group. Ó 2014 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.
Keywords: Lymph node retrieval Gastrectomy Lymphadenectomy
1. Introduction Although the incidence of gastric adenocarcinoma is declining in the United States and the Western world, this disease still remains the second leading cause of cancer death in both sexes worldwide (736 000 deaths, 9.7% of the total) [1]. It is estimated that around one million new cases of stomach cancer occurred worldwide in 2008 (988 000 cases, 7.8% of the total cancer cases), making it currently the fourth most common malignancy in the world, ranking behind cancers of the lung, breast and colo-rectum. More than 70% of gastric cancer cases occur in developing countries, and half (of the world total) occurs in Eastern Asia [2,3]. According to the American Cancer Society, the estimated number of newly diagnosed gastric cancer patients and deaths resulting
Q1
* Corresponding author. E-mail address: [email protected] (A. Halevy). 1 Affiliated to the Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, Israel.
from gastric cancer in the United States in 2012 will be 21 320 and 15 070 respectively [4]. Surgical resection is the only potentially curative therapeutic modality for patients with gastric cancer. The presence of lymph node metastasis is one of the most important prognostic factors [5]. In some centers, specimens are often dissected fresh by the pathologist adjacent to the operating theater, allowing immediate pathologic macroscopic evaluation and preparation for optimal fixation [6]. Gastric cancer, as any other specimen, needs to be dissected by and adequately trained pathologist if accurate staging is to be achieved, taking into account that while that lymph node identification and evaluation is time consuming, it is of utmost importance for accurate staging [7]. 2. Material and methods This retrospective study was conducted with the authorization of our International Review Board (IRB Judgement’s Reference No. 223/13). Data was retrieved from patient charts and pathological reports and a computerized database was created.
http://dx.doi.org/10.1016/j.ijsu.2014.05.057 1743-9191/Ó 2014 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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Since 2009, we have been using acetone as a fat dissolving solution. Our current study compares the results during the years 2005e2008 using manual dissection to the results during the years 2009e2012 using acetone. All patients diagnosed with gastric cancer underwent a staging process including total body computed tomography (CT) scanning with selective use of positron emission tomography and computed tomography (PET CT), and tumor markers (CEA, CA 19-9). From 209 patients diagnosed with gastric cancer, 85 were excluded due to metastatic disease, patient decision or general condition. The remaining 124 patients underwent surgery beginning with diagnostic laparoscopy. The peritoneal cavity was insufflated to 15 mmHg and two 5 mm trocars were introduced. Any suspicious lesion was biopsied and sent for frozen section, and peritoneal fluid was sent for cytology. An open D2 type gastric resection was performed whenever the tumor was judged resectable. All surgeries were performed by senior residents supervised by two attending surgical oncologists. The specimens were evaluated using two different methods: 61 were embedded in formalin and compared to 63 gastrectomy specimens placed in acetone for 16 h followed by lymph node isolation. Statistical analyses were performed at the Department of Statistics of the Tel Aviv University. The Student’s test, and Manne Whitney rank sum test were used for statistical evaluation and the level of significance was 5%. 3. Results Both groups were comparable for demographic data, tumor location, type of operation, tumor histology and staging (Table 1). The average number of harvested nodes per patient in the formalin group was 19.3 compared to 26.1 in the group of patients in the acetone group (P ¼ 0.003) (Fig. 1). The difference in the average number of positive lymph nodes did not reach statistical significance: 4.6 in the formalin group as compared to 6.9 in the acetone group (P ¼ 0.22). The proportion of positive lymph nodes in the formalin group was 279/1177 (23%) compared to 430/1668 in the acetone group (25%). 4. Discussion The number of harvested lymph nodes is considered the best parameter known at present to evaluate the radicality of any Table 1 Demographics.
Number Age Male/female Location Esophago-gastric junction Upper stomach Middle stomach Lower stomach Linitis plastica Type of surgery Proximal Sub-total Total Pathology Adenocarcinoma Signet-ring cell carcinoma Staging I II III IV
Acetone
Non-acetone
Overall
63 66 12 48/17
61 69 12 43/18
124 67.5 12 91/35
4 13 20 24 2
5 9 17 27 3
9 22 37 51 5
15 13 25
10 12 39
25 25 74
49 14
48 13
97 27
24 12 14 13
20 9 24 8
44 212 38 21
Fig. 1. Total lymph node count/positive nodes.
surgical procedure for cancer and specifically gastric cancer with its multiple lymph node drainage stations [7]. Surgeons with thorough anatomical knowledge of the various lymph node stations and surgical experience should perform the gastrectomy, and experienced pathologists should examine and count lymph nodes creating standardization of the operative procedure and pathological evaluation. Inadequate lymph node harvesting may contribute to stage migration associated with poorer long-term clinical outcomes resulting from pathological under staging [8e11]. Specifically in cases of gastric cancer, the overall number of harvested lymph nodes depends on which type of lymph node dissection is performed, a D1 or a D2 type, with the expectation of a much lower number of nodes in D1. However, a huge difference in the number of lymph nodes is seen, not only in different studies, but also in different individual patients operated by the same team of surgeons and specimens evaluated by the same team of pathologists [12,13]. This fact should raise the existence of another component of the equation, which is the individual anatomical difference of the number of lymph nodes between different individuals. The American Joint Committee on Cancer (AJCC) requests a minimum number of 16 harvested lymph nodes in order to precisely stage gastric cancer patients [8]. The Intergroup 0116 trial found that only 10% of patients undergoing gastrectomy in the USA underwent the recommended D2 lymph node dissection, 36% underwent D1 LN dissection, and 54% had inadequate lymph node dissection [14]. Inadequate lymph node staging has also been reported in colon cancer patients, with resultant staging inaccuracies and reported worse survival [6,15]. Peyre et al. [16] showed that in esophageal cancer the number of lymph nodes removed is an independent predictor of survival and to maximize the survival benefit a minimum of 23 regional lymph nodes must be removed. Some studies dealing with gastric cancer demonstrated improved survival rates for patients who underwent extended dissection, and the recommendation of the Japanese Research Society for the Study of Gastric Cancer is routine performance of a D2 lymph node dissection [11]. Takashi et al. [12] showed that among patients who underwent gastrectomy without any lymph node metastasis, patients with 1e4 examined nodes and those with five to nine examined nodes had a significantly lower survival rate than patients with 10e14 and 15 or more examined nodes. Only few studies dealing with gastric cancer reported on the relation between DFS and lymph node assessment and showed longer time to recurrence when more lymph nodes were assessed
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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[17,18]. Sacartozzi et al. [19] reported a remarkable decrease in local recurrence, from 23% in patients with 25 lymph nodes assessed. Several studies showed a correlation between high body mass index, proximal tumor location, low hospital or surgeon volume and surgery following neoadjuvant treatment and a low number of harvested nodes [20]. In addition to the surgeon performing a radical lymph node dissection, the number of nodes depends on the thorough examination of the specimen performed by the team of pathologists [7]. Currently, most pathologists obtain lymph nodes for histologic evaluation after their identification by sight and palpation. This method for recovering lymph nodes is termed the “manual method”. A second method, termed as ‘the lymph node clearing technique’, treats the surgical specimen by using different fat dissolving solutions. The result is a translucent mesentery that preserves lymph node structure .Nodes as small as 1.0 mm may be dissected out of the clearing fat .The use of such “clearing solutions” may ‘up-stage’ some patients because of the detection of additional small involved lymph nodes otherwise not detected by the manual method. The benefit of using the acetone clearing method has already been proved in colon cancer. Vogel et al. [21] showed an average additional identification of 4.4 lymph nodes when compared to the manual method. Scott et al. [22] showed that fat clearing of the mesocolon or mesorectum should be used when traditional dissection has failed to identify at least 13 nodes and the tumor has been classified as Duke’s B. Gehoff and her colleges investigated the use of acetone in patients following preoperative radio chemotherapy and concluded that the acetone method increased lymph node retrieval three fold compared with manual dissection. In addition this study proved that the acetone method allowed reliable molecular analysis [23]. Only 43%of pathologists in a recent survey reported using fat clearing solutions, such as acetic acid [24]. Our current study using acetone as a fat clearing solution in gastric cancer specimens demonstrates the superiority of this technique over manual dissection of lymph nodes by the identification of a statistically higher number of nodes. The increased number of harvested nodes was translated in our patients into a non statistical significant change in the number of positive nodes and hence staging of the disease. In conclusion, acetone as a clearing solution used in our patients resulted in an increase in the overall number of harvested lymph nodes and as a result positive lymph nodes, but the figures were not statistically significant. The differences in the overall number of harvested lymph nodes and positive nodes between different individuals operated and specimens evaluated by the same team of surgeons and pathologists might reflect individual differences. Further research will be needed to evaluate differences in disease free and overall survival comparing the two groups. Ethical approval YES, The Institutional Review Board at Assaf Harofeh Medical Center, Judgement’s reference number: 223/13. Funding There were no sources of funding or financial support. Author contribution Study concept and design: Ron Lavy, Andronik Kapiev, Bar Chikman, Zahar Shapira, Natan Poluksht, Ariel Halevy.
3
66 67 68 69 70 71 72 73 74 75 Conflict of interest 76 77 The authors declared no conflicts of interest with respect to the 78 research, authorship, and/or publication of this article. 79 80 Brief efor website Q2 81 82 What is already known on this topic? 83 84 Lymph node metastasis is an important prognostic factor. 85 Minimum of 16 harvested lymph nodes needed to precisely 86 stage gastric cancer. 87 Acetone is being evaluated in gastric cancer. 88 89 90 What this study adds? 91 92 Number of harvested nodes related to number of positive nodes 93 and staging. 94 Acetone resulted in increased overall harvested and positive 95 lymph nodes. 96 Further studies with larger cohorts may lead to better staging 97 and treatment. 98 99 Longer e for manuscript 100 101 What is already known on this topic? 102 103 The presence of lymph node metastasis is one of the most 104 important prognostic factors. 105 The American Joint Committee on Cancer (AJCC) requests a 106 minimum number of 16 harvested lymph nodes in order to 107 precisely stage gastric cancer patients. 108 The benefit of using Acetone clearing method has already been 109 proven in colon cancer and is being evaluated in other malig110 nancies such as gastric cancer. 111 112 113 What this study adds? 114 115 The increased number of harvested nodes was translated in our 116 patients into a non significant change in the number of positive 117 nodes and hence staging of the disease. 118 In our patients, acetone as a clearing solution resulted in an 119 increase in the overall number of harvested lymph nodes and as 120 a result positive lymph nodes. 121 Further studies with larger cohort of patients using acetone may 122 lead to better staging and treatment of gastric cancer 123 124 References 125 126 [1] B. Schlansky, A. Sonnenberg, Epidemiology of noncardia gastric adenocarcinoma in the United States, Am. J. Gastroenterol. 106 (2011) 1978e1985. 127 [2] F. Kamangar, G.M. Dores, W.F. Anderson, Patterns of cancer incidence, mor128 tality, and prevalence across five continents: defining priorities to reduce 129 cancer disparities in different geographic regions of the world, J. Clin. Oncol. 130 24 (2006) 2137e2150. Analysis and interpretation of data: Ron Lavy, Nirit Yarom. Acquisition of date Ron Lavy, Andronik Kapiev, Yehuda Hershkovitz, Judith Sandbank. Drafting of the manuscript: Ron Lavy, Yehuda Hershkovitz, Andronik Kapiev, Bar Chikman, Zahar Shapira, Natan Poluksht. Critical revisions of the manuscript: Ariel Halevy, Nirit Yarom, Judith Sandbank. Approval of the final version to be submitted: All the authors.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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[3] T.E. Buffart, M. Louw, N.C. van Grieken, M. Tijssen, B. Carvalho, B. Ylstra, et al., Gastric cancers of Western European and African patients show different patterns of genomic instability, BMC Med. Genomics 106 (2011) 1978e1985. [4] R. Siegel, D. Naishadham, A. Jemal, Cancer statistics, 2012, CA Cancer J. Clin. 62 (2012) 10e29. [5] R. Lavy, A. Kapiev, N. Poluksht, A. Halevy, L. Keinan-Boker, Incidence trends and mortality rates of gastric cancer in Israel, Gastric Cancer 16 (2013) 121e125. [6] J.B. Schofield, N.A. Mounter, R. Mallett, N.Y. Haboubi, The importance of accurate pathological assessment of lymph node involvement in colorectal cancer, Colorectal Dis. 8 (2006) 460e470. [7] O. Asoglu, T. Matlim, A. Kurt, S.Y. Onder, E. Kunduz, H. Karanlik, et al., Guidelines for extended lymphadenectomy in gastric cancer: a prospective comparative study, Ann. Surg. Oncol. 20 (2013) 218e225. [8] R. Seevaratnam, A. Bocicariu, R. Cardoso, L. Yohanathan, M. Dixon, C. Law, et al., How many lymph nodes should be assessed in patients with gastric cancer? A systematic review, Gastric Cancer 15 (Suppl. 1) (2012) S70eS88. [9] R.E. Schwarz, D.D. Smith, Clinical impact of lymphadenectomy extent in resectable gastric cancer of advanced stage, Ann. Surg. Oncol. 14 (2007) 317e 328. [10] A.M. Bouvier, O. Haas, F. Piard, P. Roignot, C. Bonithon-Kopp, J. Faivre, How many nodes must be examined to accurately stage gastric carcinomas? Results from a population based study, Cancer 94 (2002) 2862e2866. [11] B.R. Smith, B.E. Stabile, Aggressive D2 lymphadenectomy is required for accurate pathologic staging of gastric adenocarcinoma, Am. Surg. 72 (2006) 849e852. [12] T. Ichikura, T. Ogawa, K. Chochi, T. Kawabata, H. Sugasawa, H. Mochizuki, Minimum number of lymph nodes that should be examined for the international union against cancer/American Joint Committee on Cancer TNM classification of gastric carcinoma, World J. Surg. 27 (2003) 330e333. 13 D. Xu, Y. Huang, Q. Geng, Y. Guan, Y. Li, W. Wang, et al., Effect of lymph node number on survival of patients with lymph node-negative gastric cancer according to the 7th edition UICC TNM system, PLoS One 7 (2012) e38681. [14] N.N. Baxter, T.M. Tuttle, Inadequacy of lymph node staging in gastric cancer patients: a population-based study, Ann. Surg. Oncol. 12 (2005) 981e987.
[15] H.G. Brown, T.M. Luckasevic, D.S. Medich, J.P. Celebrezze, S.M. Jones, Efficacy of manual dissection of lymph nodes in colon cancer resections, Mod. Pathol. 17 (2004) 402e406. [16] C.G. Peyre, J.A. Hagen, S.R. DeMeester, N.K. Altorki, E. Ancona, S.M. Griffin, et al., The number of lymph nodes removed predicts survival in esophageal cancer: an international study on the impact of extent of surgical resection, Ann. Surg. 248 (2008) 549e556. [17] J.Y. Deng, H. Liang, D. Sun, Y. Pan, R.P. Zhang, B.G. Wang, et al., Outcome in relation to numbers of nodes harvested in lymph node-positive gastric cancer, Eur. J. Surg. Oncol. 35 (2009) 814e819. [18] C.M. Huang, J.X. Lin, C.H. Zheng, P. Li, J.W. Xie, B.J. Lin, et al., Prognostic impact of dissected lymph node count on patients with node-negative gastric cancer, World J. Gastroenterol. 15 (2009) 3926e3930. [19] M. Scartozzi, E. Galizia, F. Graziano, V. Catalano, R. Berardi, A.M. Baldelli, et al., Over-DI dissection may question the value of radiotherapy as a part of an adjuvant programme in high-risk radically resected gastric cancer patients, Br. J. Cancer 92 (2005) 1051e1054. [20] N.G. Coburn, C.J. Swallow, A. Kiss, C. Law, Significant regional variation in adequacy of lymph node assessment and survival in gastric cancer, Cancer 107 (2006) 2143e2151. [21] C. Vogel, T. Kirtil, F. Oellig, M. Stolte, Lymph node preparation in resected colorectal carcinoma specimens employing the acetone clearing method, Pathol. Res. Pract. 204 (2008) 11e15. [22] K.W. Scott, R.H. Grace, Detection of lymph node metastases in colorectal carcinoma before and after fat clearance, Br. J. Surg. 76 (1989) 1165e1167. [23] A. Gehoff, O. Basten, T. Sprenger, L.C. Conradi, C. Bismarck, D. Bandorski, et al., Optimal lymph node harvest in rectal cancer (UICC stages II and III) after preoperative 5-FU-based radiochemotherapy. Acetone compression is a new and highly efficient method, Am. J. Surg. Pathol. 36 (2012) 202e213. [24] E. Arav, M. Picot, E. De La Tour Du Pin, N. Yaziji, E. Majek, M. Patey, et al., How to optimize lymph node dissection in colorectal cancers. A technique for simple and efficacious clarification, Ann. Pathol. 19 (1999) 147e150.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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International Journal of Surgery xxx (2014) 1e4
Contents lists available at ScienceDirect
International Journal of Surgery journal homepage: www.journal-surgery.net
Original research
A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy Q3
Ron Lavy a,1, Yehuda Hershkovitz a,1, Andronik Kapiev a,1, Bar Chikman a,1, Zahar Shapira a,1, Natan Poluksht a,1, Nirit Yarom b,1, Judith Sandbank c,1, Ariel Halevy a, *,1 a b c
Division of Surgery, Assaf Harofeh Medical Center, Zerifin 70300, Israel Institute of Oncology, Assaf Harofeh Medical Center, Zerifin, Israel Institute of Pathology, Assaf Harofeh Medical Center, Zerifin, Israel
a r t i c l e i n f o
a b s t r a c t
Article history: Received 4 February 2014 Received in revised form 24 April 2014 Accepted 9 May 2014 Available online xxx
Background: The number of lymph nodes harvested during gastrectomy depends on the extension of lymphadenectomy and the method of lymph node retrieval. Aim: The objective of this study was to evaluate two methods of lymph node retrieval in specimens of gastric cancer. Methods: The number of lymph nodes was compared using two different techniques. The technique used in the first group was manual dissection following formalin fixation, and the techniques used in the second group was fat-clearing by acetone. Results: Both groups were comparable for demographic and pathological variables. The average number of harvested nodes was 19.3 10 for the manual group as compared to 26.1 14 in the acetone group (P ¼ 0.003). The differences in the average number of positive nodes did not reach statistical significance (4.6 compared to 6.9 nodes). Conclusion: The acetone clearing technique enables the evaluation of a larger number of nodes. An increase, but statistically non significant, number of positive nodes was noted in the acetone group. Ó 2014 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.
Keywords: Lymph node retrieval Gastrectomy Lymphadenectomy
1. Introduction Although the incidence of gastric adenocarcinoma is declining in the United States and the Western world, this disease still remains the second leading cause of cancer death in both sexes worldwide (736 000 deaths, 9.7% of the total) [1]. It is estimated that around one million new cases of stomach cancer occurred worldwide in 2008 (988 000 cases, 7.8% of the total cancer cases), making it currently the fourth most common malignancy in the world, ranking behind cancers of the lung, breast and colo-rectum. More than 70% of gastric cancer cases occur in developing countries, and half (of the world total) occurs in Eastern Asia [2,3]. According to the American Cancer Society, the estimated number of newly diagnosed gastric cancer patients and deaths resulting
Q1
* Corresponding author. E-mail address: [email protected] (A. Halevy). 1 Affiliated to the Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, Israel.
from gastric cancer in the United States in 2012 will be 21 320 and 15 070 respectively [4]. Surgical resection is the only potentially curative therapeutic modality for patients with gastric cancer. The presence of lymph node metastasis is one of the most important prognostic factors [5]. In some centers, specimens are often dissected fresh by the pathologist adjacent to the operating theater, allowing immediate pathologic macroscopic evaluation and preparation for optimal fixation [6]. Gastric cancer, as any other specimen, needs to be dissected by and adequately trained pathologist if accurate staging is to be achieved, taking into account that while that lymph node identification and evaluation is time consuming, it is of utmost importance for accurate staging [7]. 2. Material and methods This retrospective study was conducted with the authorization of our International Review Board (IRB Judgement’s Reference No. 223/13). Data was retrieved from patient charts and pathological reports and a computerized database was created.
http://dx.doi.org/10.1016/j.ijsu.2014.05.057 1743-9191/Ó 2014 Published by Elsevier Ltd on behalf of Surgical Associates Ltd.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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Since 2009, we have been using acetone as a fat dissolving solution. Our current study compares the results during the years 2005e2008 using manual dissection to the results during the years 2009e2012 using acetone. All patients diagnosed with gastric cancer underwent a staging process including total body computed tomography (CT) scanning with selective use of positron emission tomography and computed tomography (PET CT), and tumor markers (CEA, CA 19-9). From 209 patients diagnosed with gastric cancer, 85 were excluded due to metastatic disease, patient decision or general condition. The remaining 124 patients underwent surgery beginning with diagnostic laparoscopy. The peritoneal cavity was insufflated to 15 mmHg and two 5 mm trocars were introduced. Any suspicious lesion was biopsied and sent for frozen section, and peritoneal fluid was sent for cytology. An open D2 type gastric resection was performed whenever the tumor was judged resectable. All surgeries were performed by senior residents supervised by two attending surgical oncologists. The specimens were evaluated using two different methods: 61 were embedded in formalin and compared to 63 gastrectomy specimens placed in acetone for 16 h followed by lymph node isolation. Statistical analyses were performed at the Department of Statistics of the Tel Aviv University. The Student’s test, and Manne Whitney rank sum test were used for statistical evaluation and the level of significance was 5%. 3. Results Both groups were comparable for demographic data, tumor location, type of operation, tumor histology and staging (Table 1). The average number of harvested nodes per patient in the formalin group was 19.3 compared to 26.1 in the group of patients in the acetone group (P ¼ 0.003) (Fig. 1). The difference in the average number of positive lymph nodes did not reach statistical significance: 4.6 in the formalin group as compared to 6.9 in the acetone group (P ¼ 0.22). The proportion of positive lymph nodes in the formalin group was 279/1177 (23%) compared to 430/1668 in the acetone group (25%). 4. Discussion The number of harvested lymph nodes is considered the best parameter known at present to evaluate the radicality of any Table 1 Demographics.
Number Age Male/female Location Esophago-gastric junction Upper stomach Middle stomach Lower stomach Linitis plastica Type of surgery Proximal Sub-total Total Pathology Adenocarcinoma Signet-ring cell carcinoma Staging I II III IV
Acetone
Non-acetone
Overall
63 66 12 48/17
61 69 12 43/18
124 67.5 12 91/35
4 13 20 24 2
5 9 17 27 3
9 22 37 51 5
15 13 25
10 12 39
25 25 74
49 14
48 13
97 27
24 12 14 13
20 9 24 8
44 212 38 21
Fig. 1. Total lymph node count/positive nodes.
surgical procedure for cancer and specifically gastric cancer with its multiple lymph node drainage stations [7]. Surgeons with thorough anatomical knowledge of the various lymph node stations and surgical experience should perform the gastrectomy, and experienced pathologists should examine and count lymph nodes creating standardization of the operative procedure and pathological evaluation. Inadequate lymph node harvesting may contribute to stage migration associated with poorer long-term clinical outcomes resulting from pathological under staging [8e11]. Specifically in cases of gastric cancer, the overall number of harvested lymph nodes depends on which type of lymph node dissection is performed, a D1 or a D2 type, with the expectation of a much lower number of nodes in D1. However, a huge difference in the number of lymph nodes is seen, not only in different studies, but also in different individual patients operated by the same team of surgeons and specimens evaluated by the same team of pathologists [12,13]. This fact should raise the existence of another component of the equation, which is the individual anatomical difference of the number of lymph nodes between different individuals. The American Joint Committee on Cancer (AJCC) requests a minimum number of 16 harvested lymph nodes in order to precisely stage gastric cancer patients [8]. The Intergroup 0116 trial found that only 10% of patients undergoing gastrectomy in the USA underwent the recommended D2 lymph node dissection, 36% underwent D1 LN dissection, and 54% had inadequate lymph node dissection [14]. Inadequate lymph node staging has also been reported in colon cancer patients, with resultant staging inaccuracies and reported worse survival [6,15]. Peyre et al. [16] showed that in esophageal cancer the number of lymph nodes removed is an independent predictor of survival and to maximize the survival benefit a minimum of 23 regional lymph nodes must be removed. Some studies dealing with gastric cancer demonstrated improved survival rates for patients who underwent extended dissection, and the recommendation of the Japanese Research Society for the Study of Gastric Cancer is routine performance of a D2 lymph node dissection [11]. Takashi et al. [12] showed that among patients who underwent gastrectomy without any lymph node metastasis, patients with 1e4 examined nodes and those with five to nine examined nodes had a significantly lower survival rate than patients with 10e14 and 15 or more examined nodes. Only few studies dealing with gastric cancer reported on the relation between DFS and lymph node assessment and showed longer time to recurrence when more lymph nodes were assessed
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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[17,18]. Sacartozzi et al. [19] reported a remarkable decrease in local recurrence, from 23% in patients with 25 lymph nodes assessed. Several studies showed a correlation between high body mass index, proximal tumor location, low hospital or surgeon volume and surgery following neoadjuvant treatment and a low number of harvested nodes [20]. In addition to the surgeon performing a radical lymph node dissection, the number of nodes depends on the thorough examination of the specimen performed by the team of pathologists [7]. Currently, most pathologists obtain lymph nodes for histologic evaluation after their identification by sight and palpation. This method for recovering lymph nodes is termed the “manual method”. A second method, termed as ‘the lymph node clearing technique’, treats the surgical specimen by using different fat dissolving solutions. The result is a translucent mesentery that preserves lymph node structure .Nodes as small as 1.0 mm may be dissected out of the clearing fat .The use of such “clearing solutions” may ‘up-stage’ some patients because of the detection of additional small involved lymph nodes otherwise not detected by the manual method. The benefit of using the acetone clearing method has already been proved in colon cancer. Vogel et al. [21] showed an average additional identification of 4.4 lymph nodes when compared to the manual method. Scott et al. [22] showed that fat clearing of the mesocolon or mesorectum should be used when traditional dissection has failed to identify at least 13 nodes and the tumor has been classified as Duke’s B. Gehoff and her colleges investigated the use of acetone in patients following preoperative radio chemotherapy and concluded that the acetone method increased lymph node retrieval three fold compared with manual dissection. In addition this study proved that the acetone method allowed reliable molecular analysis [23]. Only 43%of pathologists in a recent survey reported using fat clearing solutions, such as acetic acid [24]. Our current study using acetone as a fat clearing solution in gastric cancer specimens demonstrates the superiority of this technique over manual dissection of lymph nodes by the identification of a statistically higher number of nodes. The increased number of harvested nodes was translated in our patients into a non statistical significant change in the number of positive nodes and hence staging of the disease. In conclusion, acetone as a clearing solution used in our patients resulted in an increase in the overall number of harvested lymph nodes and as a result positive lymph nodes, but the figures were not statistically significant. The differences in the overall number of harvested lymph nodes and positive nodes between different individuals operated and specimens evaluated by the same team of surgeons and pathologists might reflect individual differences. Further research will be needed to evaluate differences in disease free and overall survival comparing the two groups. Ethical approval YES, The Institutional Review Board at Assaf Harofeh Medical Center, Judgement’s reference number: 223/13. Funding There were no sources of funding or financial support. Author contribution Study concept and design: Ron Lavy, Andronik Kapiev, Bar Chikman, Zahar Shapira, Natan Poluksht, Ariel Halevy.
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66 67 68 69 70 71 72 73 74 75 Conflict of interest 76 77 The authors declared no conflicts of interest with respect to the 78 research, authorship, and/or publication of this article. 79 80 Brief efor website Q2 81 82 What is already known on this topic? 83 84 Lymph node metastasis is an important prognostic factor. 85 Minimum of 16 harvested lymph nodes needed to precisely 86 stage gastric cancer. 87 Acetone is being evaluated in gastric cancer. 88 89 90 What this study adds? 91 92 Number of harvested nodes related to number of positive nodes 93 and staging. 94 Acetone resulted in increased overall harvested and positive 95 lymph nodes. 96 Further studies with larger cohorts may lead to better staging 97 and treatment. 98 99 Longer e for manuscript 100 101 What is already known on this topic? 102 103 The presence of lymph node metastasis is one of the most 104 important prognostic factors. 105 The American Joint Committee on Cancer (AJCC) requests a 106 minimum number of 16 harvested lymph nodes in order to 107 precisely stage gastric cancer patients. 108 The benefit of using Acetone clearing method has already been 109 proven in colon cancer and is being evaluated in other malig110 nancies such as gastric cancer. 111 112 113 What this study adds? 114 115 The increased number of harvested nodes was translated in our 116 patients into a non significant change in the number of positive 117 nodes and hence staging of the disease. 118 In our patients, acetone as a clearing solution resulted in an 119 increase in the overall number of harvested lymph nodes and as 120 a result positive lymph nodes. 121 Further studies with larger cohort of patients using acetone may 122 lead to better staging and treatment of gastric cancer 123 124 References 125 126 [1] B. Schlansky, A. Sonnenberg, Epidemiology of noncardia gastric adenocarcinoma in the United States, Am. J. Gastroenterol. 106 (2011) 1978e1985. 127 [2] F. Kamangar, G.M. Dores, W.F. Anderson, Patterns of cancer incidence, mor128 tality, and prevalence across five continents: defining priorities to reduce 129 cancer disparities in different geographic regions of the world, J. Clin. Oncol. 130 24 (2006) 2137e2150. Analysis and interpretation of data: Ron Lavy, Nirit Yarom. Acquisition of date Ron Lavy, Andronik Kapiev, Yehuda Hershkovitz, Judith Sandbank. Drafting of the manuscript: Ron Lavy, Yehuda Hershkovitz, Andronik Kapiev, Bar Chikman, Zahar Shapira, Natan Poluksht. Critical revisions of the manuscript: Ariel Halevy, Nirit Yarom, Judith Sandbank. Approval of the final version to be submitted: All the authors.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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[3] T.E. Buffart, M. Louw, N.C. van Grieken, M. Tijssen, B. Carvalho, B. Ylstra, et al., Gastric cancers of Western European and African patients show different patterns of genomic instability, BMC Med. Genomics 106 (2011) 1978e1985. [4] R. Siegel, D. Naishadham, A. Jemal, Cancer statistics, 2012, CA Cancer J. Clin. 62 (2012) 10e29. [5] R. Lavy, A. Kapiev, N. Poluksht, A. Halevy, L. Keinan-Boker, Incidence trends and mortality rates of gastric cancer in Israel, Gastric Cancer 16 (2013) 121e125. [6] J.B. Schofield, N.A. Mounter, R. Mallett, N.Y. Haboubi, The importance of accurate pathological assessment of lymph node involvement in colorectal cancer, Colorectal Dis. 8 (2006) 460e470. [7] O. Asoglu, T. Matlim, A. Kurt, S.Y. Onder, E. Kunduz, H. Karanlik, et al., Guidelines for extended lymphadenectomy in gastric cancer: a prospective comparative study, Ann. Surg. Oncol. 20 (2013) 218e225. [8] R. Seevaratnam, A. Bocicariu, R. Cardoso, L. Yohanathan, M. Dixon, C. Law, et al., How many lymph nodes should be assessed in patients with gastric cancer? A systematic review, Gastric Cancer 15 (Suppl. 1) (2012) S70eS88. [9] R.E. Schwarz, D.D. Smith, Clinical impact of lymphadenectomy extent in resectable gastric cancer of advanced stage, Ann. Surg. Oncol. 14 (2007) 317e 328. [10] A.M. Bouvier, O. Haas, F. Piard, P. Roignot, C. Bonithon-Kopp, J. Faivre, How many nodes must be examined to accurately stage gastric carcinomas? Results from a population based study, Cancer 94 (2002) 2862e2866. [11] B.R. Smith, B.E. Stabile, Aggressive D2 lymphadenectomy is required for accurate pathologic staging of gastric adenocarcinoma, Am. Surg. 72 (2006) 849e852. [12] T. Ichikura, T. Ogawa, K. Chochi, T. Kawabata, H. Sugasawa, H. Mochizuki, Minimum number of lymph nodes that should be examined for the international union against cancer/American Joint Committee on Cancer TNM classification of gastric carcinoma, World J. Surg. 27 (2003) 330e333. 13 D. Xu, Y. Huang, Q. Geng, Y. Guan, Y. Li, W. Wang, et al., Effect of lymph node number on survival of patients with lymph node-negative gastric cancer according to the 7th edition UICC TNM system, PLoS One 7 (2012) e38681. [14] N.N. Baxter, T.M. Tuttle, Inadequacy of lymph node staging in gastric cancer patients: a population-based study, Ann. Surg. Oncol. 12 (2005) 981e987.
[15] H.G. Brown, T.M. Luckasevic, D.S. Medich, J.P. Celebrezze, S.M. Jones, Efficacy of manual dissection of lymph nodes in colon cancer resections, Mod. Pathol. 17 (2004) 402e406. [16] C.G. Peyre, J.A. Hagen, S.R. DeMeester, N.K. Altorki, E. Ancona, S.M. Griffin, et al., The number of lymph nodes removed predicts survival in esophageal cancer: an international study on the impact of extent of surgical resection, Ann. Surg. 248 (2008) 549e556. [17] J.Y. Deng, H. Liang, D. Sun, Y. Pan, R.P. Zhang, B.G. Wang, et al., Outcome in relation to numbers of nodes harvested in lymph node-positive gastric cancer, Eur. J. Surg. Oncol. 35 (2009) 814e819. [18] C.M. Huang, J.X. Lin, C.H. Zheng, P. Li, J.W. Xie, B.J. Lin, et al., Prognostic impact of dissected lymph node count on patients with node-negative gastric cancer, World J. Gastroenterol. 15 (2009) 3926e3930. [19] M. Scartozzi, E. Galizia, F. Graziano, V. Catalano, R. Berardi, A.M. Baldelli, et al., Over-DI dissection may question the value of radiotherapy as a part of an adjuvant programme in high-risk radically resected gastric cancer patients, Br. J. Cancer 92 (2005) 1051e1054. [20] N.G. Coburn, C.J. Swallow, A. Kiss, C. Law, Significant regional variation in adequacy of lymph node assessment and survival in gastric cancer, Cancer 107 (2006) 2143e2151. [21] C. Vogel, T. Kirtil, F. Oellig, M. Stolte, Lymph node preparation in resected colorectal carcinoma specimens employing the acetone clearing method, Pathol. Res. Pract. 204 (2008) 11e15. [22] K.W. Scott, R.H. Grace, Detection of lymph node metastases in colorectal carcinoma before and after fat clearance, Br. J. Surg. 76 (1989) 1165e1167. [23] A. Gehoff, O. Basten, T. Sprenger, L.C. Conradi, C. Bismarck, D. Bandorski, et al., Optimal lymph node harvest in rectal cancer (UICC stages II and III) after preoperative 5-FU-based radiochemotherapy. Acetone compression is a new and highly efficient method, Am. J. Surg. Pathol. 36 (2012) 202e213. [24] E. Arav, M. Picot, E. De La Tour Du Pin, N. Yaziji, E. Majek, M. Patey, et al., How to optimize lymph node dissection in colorectal cancers. A technique for simple and efficacious clarification, Ann. Pathol. 19 (1999) 147e150.
Please cite this article in press as: R. Lavy, et al., A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy, International Journal of Surgery (2014), http://dx.doi.org/10.1016/j.ijsu.2014.05.057
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