Original Article

Retrospective analysis of clinical and pathologic risk factors in liver resection for hepatic colorectal metastases ABSTRACT Objective: To analyze the clinical and pathologic risk factors of surgical treatment for liver metastases from colorectal cancer. Materials and Methods: The data on 98 patients who underwent liver resection for hepatic colorectal metastases were collected and analyzed retrospectively. Results: Overall 1-, 3-, and 5-year survival rates after hepatectomy for metastases were 94.6%, 45.0%, and 22.3%, respectively. Gender, pathologic primary tumor stage, histologic differentiation, size of metastatic tumor, and type of metastases were not statistically significant prognostic factors (P > 0.05). The 5-year survival rate was significantly lower in patients with lymph node metastases from the primary site than that in patients without lymph node metastases (14.1% vs. 39.5%, P = 0.013); survival rate in patients with vascular invasion from the primary tumor was also significantly lower than in those without invasion (10.2% vs. 49.0%, P = 0.032). The survival rate in patients who had unilobar metastases was higher than that in patients who had bilobar metastases (25.3% vs. 0%, P = 0.012). The 5-year survival rates in solitary metastasis, two to three metastases, and with the transfer number 4 were 29.1%, 14.4%, and 0%, respectively (P = 0.019). Multivariate analysis revealed resection margin, distribution of metastases, and the number of metastases as the independent risk factors associated with the overall survival rates (P = 0.044, 0.037, and 0.005, respectively). Conclusions: Surgical resection may be the only treatment modality for the cure of colorectal liver metastases. Negative resection margin, metastases confined to unilobar type, and number of metastases 3 are associated with better prognosis. KEY WORDS: Colorectal cancer, hepatic metastases, liver resection, prognosis

INTRODUCTION Liver metastasis from colorectal cancer is the most important prognostic factor for which surgical resection is the only curative modality. In most studies, the overall 5-year survival rate reported following hepatic resection with curative intent ranges from 25% to 37%, with a median survival between 24 and 40 months.[1-4] But there is still controversy regarding patient selection. Many have addressed the influence of various clinical and pathologic parameters on the outcome or resective therapy, but the results vary considerably from study to study. We have reexamined our 127 consecutive patients who underwent hepatic resection for colorectal metastases during the last 13 years to identify the clinical and pathologic prognostic factors. MATERIALS AND METHODS Patients At the China-Japan Friendship Hospital, 127 patients underwent hepatic resection for metastatic S176

colorectal carcinoma during a 13-year period from January 2000 to December 2012. These were all attempts at curative resection. Of these, 4 cases of perioperative death, 24 cases of clinical or incomplete follow-up data, and 1 case of occult colorectal liver metastases were excluded. Ninety-eight cases with complete data were included in the study. All patients were pathologically confirmed with hepatic colorectal metastases, in which there were 42 cases of synchronous liver metastases and 56 cases of metachronous liver metastases. The 60 men and 38 women ranged in age from 29 to 85 years, with a median age of 62 years. The primary tumor sites were: 25 cases of ascending colon, 5 cases of transverse colon, 9 cases of descending colon, 18 cases of sigmoid colon, 39 cases of rectum, and 2 cases of double primary colon. pT2 primary tumor was found in 3 cases, pT3 in 36 cases, and pT4 in 59 cases. The number of lymph node dissections ranged from 6 to 43, with a median of 14. There were 67 cases with lymph node metastases and 31 cases without lymph node metastases.

Lei Zhou, Guochao Zhag, Tao Tang, Rui Lian1, Wenyue Wang Departments of Gastrointestinal 1 Emergency, China-Japan Friendship Hospital, Beijing, China For correspondence: Dr. Wenyue Wang, Gastrointestinal Department, China-Japan Friendship Hospital, Beijing, China. E-mail: wwenyue080@ sina.com

Access this article online Website: www.cancerjournal.net DOI: 10.4103/0973-1482.122521 PMID: *** Quick Response Code:

Journal of Cancer Research and Therapeutics - Supplement 3 - 2013 - Volume 9

Zhou, et al.: Risk factors for hepatic colorectal metastases

Metastasis in the right lobe of the liver was found in 55 cases, in the left lobe of the liver in 34 cases, and it was bilobar in 9 cases. One single metastasis was found in 59 cases, two metastases in 15 cases, three metastases in 11 cases, four metastases in 8 cases, the remaining 5 patients had more than four metastases. Surgical methods and postoperative pathologic conditions Of the 98 patients, hepatic wedge resection was performed in 47 cases, 23 cases had hepatic segment resection, and 28 cases had hepatic lobe resection. Of the 59 cases with one single metastasis, hepatic wedge resection was done in 36 cases, hepatic segment resection in 9 cases, and hepatic lobe resection was performed in 14 cases. Of the 15 cases with two metastases, the above Figures were 6 cases, 5 cases, and 4 cases, respectively. In cases with three or more metastases, the proportion of hepatic lobe resection was increased. Six cases of 11 cases with three metastases, 5 cases of 8 cases with four metastases, and 4 cases of 5 cases with five or more than five metastases received hepatic lobe resection. Negative resection margin (R0 resection) was received by 83 cases and positive margin (R1 resection) by 15 cases. All cases were diagnosed as adenocarcinoma, which was poorly differentiated in 20 cases, moderately differentiated in 71 cases, and well differentiated in 7 cases.

Primary tumor characteristics and prognosis Gender, pathologic primary tumor stage (pT), and histologic differentiation degree showed no significant relationship with the 5-year survival rate (P = 0.84, 0.58, and 0.18, respectively), while the 5-year survival rate in pathologic lymph node stage (pN) positive (14.1%) was significantly lower than that in pN negative (39.5%). Vascular invasions (10.2%) were significantly lower than no vascular invasions (49.0%), and the difference was statistically significant (P = 0.013 and 0.032, respectively) [Table 1]. Relationship among characteristics of liver metastases, surgical type, and prognosis While the 5-year survival rate of synchronous liver metastases (20.1%) was lower than that of metachronous liver metastases (24.2%), no significant difference was found (P = 0.53). Metastases with maximum diameter of ≤3 cm had higher 5-year survival rate than the metastases with maximum diameter >3 cm, but the difference was not statistically significant (22.4% vs. 19.6%, P = 0.18). With the increase in the number of metastases, the 5-year survival rate also decreased; the 5-year survival rates in solitary

Follow-up Follow-up included outpatient, by letters and telephone. Patients’ follow-up ranged from 3 to 105 months, with a median time of 29 months. If patients with simultaneous liver metastases received synchronous resection, the follow-up was from surgery to the time of death as the survival time and if they received staged resection, it was from the first operation to the time of death as the survival time. In patients with metachronous metastases to the liver, the follow-up was from the date of hepatic resection to the time of death as the survival time. Statistical analysis Survival analyses were done by the Kaplan–Meier method. Differences in survival were compared using the log-rank test. Multivariate analysis was performed with the Cox Proportional Hazard Model. Statistical analysis was performed using the SPSS Statistical Software Package (version 16.0). Differences were considered significant if P < 0.05.

Figure 1: Actuarial overall survival following hepatic resection for colorectal liver metastases

RESULTS The Kaplan–Meier curve for overall survival is shown in Figure 1. The overall survival rate was 94.6% at 1 year, 45.0% at 3 years, and 22.3% at 5 years, with a median survival of 30 months. The survival rate in patients who received R0 resection was 94.9% at 1 year, 49.9% at 3 years, and 26.9% at 5 years, with a median survival of 36 months, higher than that of patients with R1 resection, which was 93.3% at 1 year, 20.1% at 3 years, and 0% at 5 years, with a median survival of 24 months [Figure 2]. Journal of Cancer Research and Therapeutics - Supplement 3 - 2013 - Volume 9

Figure 2: Overall survival according to microscopic resection margin S177

Zhou, et al.: Risk factors for hepatic colorectal metastases

Table 1: Univariate and multivariate predictors of overall survival

Gender Male Female pT T2 T3 T4 pN Nneg Npos Histology Well differentiated Moderately differentiated Poorly differentiated Vascular invasion No Yes Type of metastases Synchronous Metachronous Distribution of metastases Unilobar Bilobar Number of metastases 1 lesion 2-3 lesions ≥4 lesions Largest size of metastasis ≤3 cm >3 cm Microscopic resection margin Negative Positive Resection type Hepatic wedge resection Hepatic segment resection Hepatic lobe resection

No. of patients

Median survival (months)

5-year survival rates (%)

60 38

39 26

19.7 26

3 36 59

31 29 28

50.0 20.7 21.1

31 67

53 24

39.5 14.1

7 71 20

49 31 23

22.9 26.4 10.8

28 70

62 26

49.0 10.2

42 56

25 41

20.1 24.2

89 9

31 24

25.3 0

59 26 13

36 43 18

29.1 14.4 0

52 46

39 24

22.4 19.6

83 15

36 24

26.9 0

47 23 28

26 28 31

18.6 36.8 17.7

Univariate analysis (P value) 0.84

Multivariate analysis (P value)

0.58

0.013

0.053

0.18

0.032

0.397

0.53 0.012

0.037

0.019

0.005

0.18 0.002

0.044

0.745

pT=Pathologic primary tumour stage, pN=Pathologic lymph node stage

metastasis, two to three metastases, and with the transfer number ≥4 were 29.1%, 14.4%, and 0%, respectively, and the difference was statistically significant (P = 0.019). When the liver metastases were confined to half of the liver, the 5-year survival rate was significantly higher than that of bilateral diffusion, and the difference was statistically significant (25.3% vs. 0%, P = 0.012). The 5-year survival rates in wedge resection of the liver, hepatic segment resection, and hepatic lobe resection were 18.6%, 36.8%, and 17.7%, respectively, and there was no significant difference (P = 0.745) [Table 1]. In R0 resection of liver metastases, the 5-year survival rate (26.9%) was significantly higher than in R1 resection (0%), and the difference was statistically significant (P = 0.002) [Figure 2]. Multivariate analysis Multivariate analysis of the prognostic factors for overall survival is shown in Table 1. Positive resection margin, number of metastases ≥4, and bilobar metastases were poor prognostic signs. S178

DISCUSSION Approximately 50-60% of patients diagnosed with colorectal cancer will develop colorectal metastases.[5-7] Metastatic disease most frequently develops metachronously after treatment for locoregional colorectal cancer, with the liver as the most common site of involvement.[8] However, 20-34% of patients with colorectal cancer present with synchronous liver metastases.[9,10] In this study, we found 42 cases of synchronous liver metastases and 56 cases of metachronous liver metastases. This result is consistent with the previous reports. Although metachronous metastases are often associated with local recurrence, lymph node metastases, or pulmonary metastases, and lost opportunities for radical surgery, the prognosis of metachronous liver metastases seems better than synchronous liver metastases. In a retrospective study of 155 patients who underwent hepatic resection for colorectal liver metastases, patients with synchronous liver metastases had more sites of liver involvement (P = 0.008) and more Journal of Cancer Research and Therapeutics - Supplement 3 - 2013 - Volume 9

Zhou, et al.: Risk factors for hepatic colorectal metastases

bilobar metastases (P = 0.016) than the patients diagnosed with metachronous liver metastases.[11] Multivariate analysis of the study showed that the distribution and the number of tumor metastases are independent prognostic factors. In addition, this analysis demonstrated the 5-year survival rate of synchronous liver metastases to be lower than that of metachronous liver metastases (20.1% vs. 24.2%). It can be explained by the fact that synchronous metastatic colorectal liver disease is associated with a more disseminated disease state than the metastatic colorectal liver disease that develops metachronously. But the difference was not statistically significant in this study, which may be due to the small number of cases. Several studies have shown the rates of 5-year survival to be low in patients with metastatic liver disease not undergoing surgery.[6,12] Factors influencing the prognosis of patients with hepatic colorectal metastases included the size, number, and distribution of metastases, condition of the primary tumor, the presence of extrahepatic tumor, preoperative carcinoembryonic antigen (CEA) level, synchronous or metachronous liver metastases, resection types, and microscopic resection margin.[13] However, some studies report different results. It may be due to the different inclusion criteria and difference in cases. Univariate analysis of the retrospective study showed that the primary tumor with lymph node metastases, vascular invasion, hepatic bilobar metastases, metastases number ≥4, and liver positive microscopic resection margin of liver metastases poor prognostic factors. Multivariate analysis of Cox showed that the microscopic resection margin, the distribution scope, and the number of liver metastases are independent prognostic factors. We found that positive resection margin, bilobar distribution of metastases, and liver metastases ≥4 had a significant deleterious effect on overall survival. In addition, this study showed that the 5-year survival rate in patients with poorly differentiated primary tumor and liver metastases with diameter >3 cm had decreased, but the difference was not statistically significant. According to the National comprehensive cancer network (NCCN) guidelines, cytoreductive surgery is not beneficial to patients. So, we should try to do radical hepatectomy. Resection should include all possible metastases and at least 1 cm outside of metastases. The results of Are et al.[14] showed that cutting-edge distance of >1 cm is an independent prognostic factor. Our study showed that resection margin is an independent prognostic risk factor. The observations were not surprising because residual tumor constitutes surgical treatment failure from the outset and the outcome is expectedly poor. Generally, the most important factor affecting R0 resection of liver metastases and prognosis is the number of liver metastases. This study showed metastases number ≥4 and bilobar distribution of metastases are associated with poor prognosis, which may be due to missing tiny lesions or incomplete surgical margins. But with the advances in imaging and intraoperative ultrasound application, we Journal of Cancer Research and Therapeutics - Supplement 3 - 2013 - Volume 9

believe that the number of liver metastases cannot serve as an absolute contraindication to surgery. As long as radical resection can be reached and can ensure adequate residual liver function, liver resection can be considered, especially for metastases confined to half of the liver and metastases

Retrospective analysis of clinical and pathologic risk factors in liver resection for hepatic colorectal metastases.

To analyze the clinical and pathologic risk factors of surgical treatment for liver metastases from colorectal cancer...
268KB Sizes 0 Downloads 0 Views