LETTERS TO THE EDITOR Another countertraction method was used in same case? To the Editor: I read Gastrointestinal Endoscopy, “Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video).1” In this article, Figure 3B was very similar to Figure 4A of their manuscript that was published in Endoscopy.2 I think this is very strange because they did not explain a different countertraction method used in the same lesion. Ippei Matsuzaki, MD Department of Gastroenterology and Hepatology Nagoya University Graduate School of Medicine Nagoya, Japan
REFERENCES 1. Aihara H, et al. Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video). Gastrointest Endosc 2014;80:495-502. 2. Aihara H, Ryou M, Kumar N, et al. A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty. Endoscopy 2014;46:422-5.
standard experimental strategy for ex vivo studies in the future. Again, thank you for your interest. Hiroyuki Aihara, MD, PhD Christopher C. Thompson, MD, MSc, FACG, FASGE Developmental Endoscopy Division of Gastroenterology Hepatology and Endoscopy Brigham and Women’s Hospital Boston, Massachusetts, USA
REFERENCE 1. Aihara H, et al. Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video). Gastrointest Endosc 2014;80:495-502. http://dx.doi.org/10.1016/j.gie.2014.05.308
Risk factors for stent-related adverse events in patients with obstructive colorectal cancer: Are we missing something? To the Editor:
We thank Dr Matsuzaki for his interest in our article, “Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study.”1 As he pointed out, one of the pictures looks similar to that in the other study, published in Endoscopy. However, as shown in our video, these 2 studies are conducted in completely different settings, and the 2 countertraction methods were not used in combination. The similarity in the pictures is because we performed the 2 studies based on the same experimental methodology we have developed, that is, pig stomachs were inverted, and 30-mm gastric lesions were simulated at exactly the same locations by using a circular template and marking dots. Thus, we believe this allowed a robust comparison of the procedure time between 2 groups by matching the lesion location and size. We are hoping that this methodology will become a
We commend van Halsema et al1 for their meta-analysis of the perforation risk of self-expandable metallic stents (SEMSs) in patients with colorectal obstruction. The authors identified 3 risk factors (stent design, benign cause, and bevacizumab treatment) that should be better understood in prospective studies, because the available data do not allow firm conclusions. Should we investigate in a different direction? In the past decade, the understanding of colorectal cancer (CRC) biology promoted targeted therapies that significantly influenced outcomes. Patients with wild-type K-ras CRC, treated with epidermal growth factor receptor (EGFR) inhibitors, have a longer survival than do patients with mutated K-ras CRC.2-4 Because the clinical success of SEMS tends to decline owing to late adverse events, the influence of such variables should be taken into account. Recently, we reported the results of a multicenter retrospective study whose main objective was to explore the relationship among K-ras mutation status, antitumoral treatments, and rates of SEMS-related adverse events.5 One of the hypotheses was whether the improved prognosis of patients with K-ras wild-type CRC would increase the risk of long-term adverse events. Ninety-one patients met the inclusion criteria (SEMSs placed for palliation, known CRC K-ras mutation status, and complete
742 GASTROINTESTINAL ENDOSCOPY Volume 80, No. 4 : 2014
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http://dx.doi.org/10.1016/j.gie.2014.05.307
Response:
Letters to the Editor
follow-up): 44 (48.4%) had K-ras wild-type tumors, and 47 (51.6%) had K-ras mutated cancers. Eighty-two patients (90.1%) underwent chemotherapy, and 45 of them (49.5%) received additional biologic therapy (11 cetuximab, 34 bevacizumab). After a mean follow-up time of 251 days, 21 (23.1%) SEMS-related adverse events were reported; K-ras mutation status and cetuximab-based treatments (odds ratio 1.2; 95% confidence interval, 0.2-5.9) were not associated with any of them. Several genetic pathways and mutations are increasingly recognized as prognostic factors in CRC patients.6-8 Therefore, future research should also aim at the identification of those risk factors related to CRC biology, for better stratifying patients with colorectal obstruction who will benefit the most from SEMSs. Lorenzo Fuccio, MD Department of Medical and Surgical Sciences University of Bologna Bologna, Italy Vincenzo Cennamo, MD Unit of Digestive Endoscopy Department of Surgery AUSL Bologna Bellaria-Maggiore Hospital Bologna, Italy Mario de Bellis, MD Endoscopy Unit Istituto Nazionale Tumori Fondazione G. Pascale – IRCCS Naples, Italy
REFERENCES 1. van Halsema EE, van Hooft JE, Small AJ, et al. Perforation in colorectal stenting: a meta-analysis and a search for risk factors. Gastrointest Endosc 2014;79:970-82. 2. Karapetis CS, Khambata-Ford S, Jonker DJ, et al. K-ras mutations and benefit from cetuximab in advanced colorectal cancer. N Engl J Med 2008;359:1757-65. 3. Amado RG, Wolf M, Peeters M, et al. Wild-type KRAS is required for panitumumab efficacy in patients with metastatic colorectal cancer. J Clin Oncol 2008;26:1626-34. 4. De Roock W, Piessevaux H, De Schutter J, et al. KRAS wild-type state predicts survival and is associated to early radiological response in metastatic colorectal cancer treated with cetuximab. Ann Oncol 2008;19:508-15. 5. Fuccio L, Correale L, Arezzo A, et al. Influence of K-ras status and antitumour treatments on complications due to colorectal self-expandable metallic stents: a retrospective multicentre study. Dig Liver Dis 2014 Mar 14. [Epub ahead of print]. 6. Eklof V, Wikberg ML, Edin S, et al. The prognostic role of KRAS, BRAF, PIK3CA and PTEN in colorectal cancer. Br J Cancer 2013;108:2153-63. 7. Phipps AI, Buchanan DD, Makar KW, et al. BRAF mutation status and survival after colorectal cancer diagnosis according to patient and tumor characteristics. Cancer Epidemiol Biomarkers Prev 2012;21:1792-8. 8. Ardekani GS, Jafarnejad SM, Tan L, et al. The prognostic value of BRAF mutation in colorectal cancer and melanoma: a systematic review and meta-analysis. PLOS one 2012;7:e47054.
The “pot-of-gold” sign: not always a lipoma To the Editor: We recently read the “At the Focal Point” case report entitled “Luminal lipoma: the ‘pot-of-gold’ sign’ with interest.1 In Dr Brandt’s commentary, he asserts that lipomas represent “the only ‘gold’ that will be mined from a colon.”1 It must be kept in mind, however, that other colonic submucosal polypoid lesions, including granular cell tumors (GCTs), should also be considered in the differential diagnosis when the “pot-of-gold” sign or yellow-colored tissue is noted during endoscopy. We report the case of a 53year-old man who underwent colonoscopy for rectal bleeding where an 8-mm smooth, sessile, lipomatousappearing, submucosal lesion was found in the ascending colon (Fig. 1). The lesion was partially resected by snare cautery polypectomy, and this showed a yellowish color on the inside of the lesion (Fig. 2) similar to that shown by Chen and Andrews.1 The polypectomy site was also noted to have a yellowish base, suggesting fatty tissue (Fig. 3). Surprisingly, the histologic appearance was consistent with GCT, showing small clusters of spindle-shaped cells and abundant granular, slightly eosinophilic cytoplasm; immunohistochemical staining was positive for S-100. The GCTs are rare, usually benign, tumors of nerve sheath origin that arise in the mucosa, submucosa, or both. They typically occur in the upper aerodigestive tract but very rarely can be seen in the colon.2-4 Most GCTs are discovered incidentally during endoscopic examination; the majority are smaller than 2 cm in diameter.2-4 Although GCTs usually do not have a “pillow sign” (given their firm consistency) and may not have lipid globules or “coins” exuding from a biopsy site, they can still appear as “gold” in the colon and must be included in the differential diagnosis of lipomatous-appearing lesions of the GI tract.
Figure 1. Submucosal polypoid lesion in the ascending colon.
http://dx.doi.org/10.1016/j.gie.2014.04.026
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Volume 80, No. 4 : 2014 GASTROINTESTINAL ENDOSCOPY 743
REFERENCES 1. Aihara H, et al. Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video). Gastrointest Endosc 2014;80:495-502. 2. Aihara H, Ryou M, Kumar N, et al. A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty. Endoscopy 2014;46:422-5.
standard experimental strategy for ex vivo studies in the future. Again, thank you for your interest. Hiroyuki Aihara, MD, PhD Christopher C. Thompson, MD, MSc, FACG, FASGE Developmental Endoscopy Division of Gastroenterology Hepatology and Endoscopy Brigham and Women’s Hospital Boston, Massachusetts, USA
REFERENCE 1. Aihara H, et al. Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video). Gastrointest Endosc 2014;80:495-502. http://dx.doi.org/10.1016/j.gie.2014.05.308
Risk factors for stent-related adverse events in patients with obstructive colorectal cancer: Are we missing something? To the Editor:
We thank Dr Matsuzaki for his interest in our article, “Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study.”1 As he pointed out, one of the pictures looks similar to that in the other study, published in Endoscopy. However, as shown in our video, these 2 studies are conducted in completely different settings, and the 2 countertraction methods were not used in combination. The similarity in the pictures is because we performed the 2 studies based on the same experimental methodology we have developed, that is, pig stomachs were inverted, and 30-mm gastric lesions were simulated at exactly the same locations by using a circular template and marking dots. Thus, we believe this allowed a robust comparison of the procedure time between 2 groups by matching the lesion location and size. We are hoping that this methodology will become a
We commend van Halsema et al1 for their meta-analysis of the perforation risk of self-expandable metallic stents (SEMSs) in patients with colorectal obstruction. The authors identified 3 risk factors (stent design, benign cause, and bevacizumab treatment) that should be better understood in prospective studies, because the available data do not allow firm conclusions. Should we investigate in a different direction? In the past decade, the understanding of colorectal cancer (CRC) biology promoted targeted therapies that significantly influenced outcomes. Patients with wild-type K-ras CRC, treated with epidermal growth factor receptor (EGFR) inhibitors, have a longer survival than do patients with mutated K-ras CRC.2-4 Because the clinical success of SEMS tends to decline owing to late adverse events, the influence of such variables should be taken into account. Recently, we reported the results of a multicenter retrospective study whose main objective was to explore the relationship among K-ras mutation status, antitumoral treatments, and rates of SEMS-related adverse events.5 One of the hypotheses was whether the improved prognosis of patients with K-ras wild-type CRC would increase the risk of long-term adverse events. Ninety-one patients met the inclusion criteria (SEMSs placed for palliation, known CRC K-ras mutation status, and complete
742 GASTROINTESTINAL ENDOSCOPY Volume 80, No. 4 : 2014
www.giejournal.org
http://dx.doi.org/10.1016/j.gie.2014.05.307
Response:
Letters to the Editor
follow-up): 44 (48.4%) had K-ras wild-type tumors, and 47 (51.6%) had K-ras mutated cancers. Eighty-two patients (90.1%) underwent chemotherapy, and 45 of them (49.5%) received additional biologic therapy (11 cetuximab, 34 bevacizumab). After a mean follow-up time of 251 days, 21 (23.1%) SEMS-related adverse events were reported; K-ras mutation status and cetuximab-based treatments (odds ratio 1.2; 95% confidence interval, 0.2-5.9) were not associated with any of them. Several genetic pathways and mutations are increasingly recognized as prognostic factors in CRC patients.6-8 Therefore, future research should also aim at the identification of those risk factors related to CRC biology, for better stratifying patients with colorectal obstruction who will benefit the most from SEMSs. Lorenzo Fuccio, MD Department of Medical and Surgical Sciences University of Bologna Bologna, Italy Vincenzo Cennamo, MD Unit of Digestive Endoscopy Department of Surgery AUSL Bologna Bellaria-Maggiore Hospital Bologna, Italy Mario de Bellis, MD Endoscopy Unit Istituto Nazionale Tumori Fondazione G. Pascale – IRCCS Naples, Italy
REFERENCES 1. van Halsema EE, van Hooft JE, Small AJ, et al. Perforation in colorectal stenting: a meta-analysis and a search for risk factors. Gastrointest Endosc 2014;79:970-82. 2. Karapetis CS, Khambata-Ford S, Jonker DJ, et al. K-ras mutations and benefit from cetuximab in advanced colorectal cancer. N Engl J Med 2008;359:1757-65. 3. Amado RG, Wolf M, Peeters M, et al. Wild-type KRAS is required for panitumumab efficacy in patients with metastatic colorectal cancer. J Clin Oncol 2008;26:1626-34. 4. De Roock W, Piessevaux H, De Schutter J, et al. KRAS wild-type state predicts survival and is associated to early radiological response in metastatic colorectal cancer treated with cetuximab. Ann Oncol 2008;19:508-15. 5. Fuccio L, Correale L, Arezzo A, et al. Influence of K-ras status and antitumour treatments on complications due to colorectal self-expandable metallic stents: a retrospective multicentre study. Dig Liver Dis 2014 Mar 14. [Epub ahead of print]. 6. Eklof V, Wikberg ML, Edin S, et al. The prognostic role of KRAS, BRAF, PIK3CA and PTEN in colorectal cancer. Br J Cancer 2013;108:2153-63. 7. Phipps AI, Buchanan DD, Makar KW, et al. BRAF mutation status and survival after colorectal cancer diagnosis according to patient and tumor characteristics. Cancer Epidemiol Biomarkers Prev 2012;21:1792-8. 8. Ardekani GS, Jafarnejad SM, Tan L, et al. The prognostic value of BRAF mutation in colorectal cancer and melanoma: a systematic review and meta-analysis. PLOS one 2012;7:e47054.
The “pot-of-gold” sign: not always a lipoma To the Editor: We recently read the “At the Focal Point” case report entitled “Luminal lipoma: the ‘pot-of-gold’ sign’ with interest.1 In Dr Brandt’s commentary, he asserts that lipomas represent “the only ‘gold’ that will be mined from a colon.”1 It must be kept in mind, however, that other colonic submucosal polypoid lesions, including granular cell tumors (GCTs), should also be considered in the differential diagnosis when the “pot-of-gold” sign or yellow-colored tissue is noted during endoscopy. We report the case of a 53year-old man who underwent colonoscopy for rectal bleeding where an 8-mm smooth, sessile, lipomatousappearing, submucosal lesion was found in the ascending colon (Fig. 1). The lesion was partially resected by snare cautery polypectomy, and this showed a yellowish color on the inside of the lesion (Fig. 2) similar to that shown by Chen and Andrews.1 The polypectomy site was also noted to have a yellowish base, suggesting fatty tissue (Fig. 3). Surprisingly, the histologic appearance was consistent with GCT, showing small clusters of spindle-shaped cells and abundant granular, slightly eosinophilic cytoplasm; immunohistochemical staining was positive for S-100. The GCTs are rare, usually benign, tumors of nerve sheath origin that arise in the mucosa, submucosa, or both. They typically occur in the upper aerodigestive tract but very rarely can be seen in the colon.2-4 Most GCTs are discovered incidentally during endoscopic examination; the majority are smaller than 2 cm in diameter.2-4 Although GCTs usually do not have a “pillow sign” (given their firm consistency) and may not have lipid globules or “coins” exuding from a biopsy site, they can still appear as “gold” in the colon and must be included in the differential diagnosis of lipomatous-appearing lesions of the GI tract.
Figure 1. Submucosal polypoid lesion in the ascending colon.
http://dx.doi.org/10.1016/j.gie.2014.04.026
www.giejournal.org
Volume 80, No. 4 : 2014 GASTROINTESTINAL ENDOSCOPY 743
