Use of 3D-CT-derived psoas major muscle volume in defining sarcopenia in colorectal cancer.

BACKGROUND: Sarcopenia is characterized by reduced skeletal muscle volume and is a condition that is prevalent among elderly patients and associated with poor prognosis as a comorbidity in malignancies. Given the aging population over 80 years old in Japan, an understanding of malignancies, including colorectal cancer (CRC), complicated by sarcopenia is increasingly important. Therefore, the focus of this study is on a novel and practical diagnostic approach of assessment of psoas major muscle volume (PV) using 3-dimensional computed tomography (3D-CT) in diagnosis of sarcopenia in patients with CRC. METHODS: The subjects were 150 patients aged ≥ 80 years with CRC who underwent primary tumor resection at Juntendo University Hospital between 2004 and 2017. 3D-CT measurement of PV and conventional CT measurement of the psoas major muscle cross-sectional area (PA) were used to identify sarcopenia (group S) and non-sarcopenia (group nS) cases. Clinicopathological characteristics, operative results, postoperative complications, and prognosis were compared between these groups. RESULTS: The S:nS ratios were 15:135 for the PV method and 52:98 for the PA method. There was a strong positive correlation (r = 0.66, p < 0.01) between PVI (psoas major muscle volume index) and PAI (psoas major muscle cross-sectional area index), which were calculated by dividing PV or PA by the square of height. Surgical results and postoperative complications did not differ significantly in the S and nS groups defined using each method. Overall survival was worse in group S compared to group nS identified by PV (p < 0.01), but not significantly different in groups S and nS identified by PA (p = 0.77). A Cox proportional hazards model for OS identified group S by PV as an independent predictor of a poor prognosis (p < 0.05), whereas group S by PA was not a predictor of prognosis (p = 0.60). CONCLUSIONS: The PV method for identifying sarcopenia in elderly patients with CRC is more practical and sensitive for prediction of a poor prognosis compared to the conventional method.

Risk factors for small-bowel obstruction after colectomy for colorectal cancer: a retrospective study.

PURPOSE: Postoperative adhesions are a concerning complication of abdominal surgery with major implications on quality of life. This study aimed to investigate the risk factors for postoperative small-bowel obstruction (SBO) after colectomy for colorectal cancer. METHODS: We reviewed the clinicopathological variables of 1646 patients who underwent colectomy for colorectal cancer between 2009 and 2018. RESULTS: SBO occurred following primary tumor resection for colorectal cancer in 67 (4.1%) of the 1646 patients. The median observation period was 7.5 (range: 3.0-12.0) years. Multivariate analysis revealed that rectal tumors, anastomotic leakages, previous abdominal surgeries, and longer operating times were all correlated with postoperative SBO, but there were no differences in the incidence of SBO between laparoscopic vs. open surgery. The use of adhesion prevention material had no effect on SBO. Our data showed that the onset of SBO tended to be relatively early, within a year after surgery (89.5%). CONCLUSIONS: Tumor localization in the rectum is associated with several problems, including a wide resection area, prolonged operative duration, and high risk of anastomotic leakage, which may increase the risk of SBO. Laparoscopic surgery and adhesion prevention material did not demonstrate a clear preventive effect against SBO.

Examination of colorectal cancer cases with metal allergy.

PURPOSE: To report our initiatives and treatment results for patients with colorectal cancer with metal allergy. METHODS: A total of 27 patients (2.6%) with a history of metal contact dermatitis were identified among 1027 patients who underwent curative resection of colorectal cancer from 2014 to 2020. The results of the patch test, perioperative results, and postoperative colonoscopy findings were also investigated. RESULTS: The patch test for metal allergens and staples was performed in 21 patients (77.8%), and 13 of them (61.9%) tested positive for at least one metal allergen. Ni (38.1%), Co (28.6%), and Pd (19.0%) showed higher positive rates than other metals, and 1 patient (4.8%) tested positive for staples. Stapled anastomosis/suturing was performed as planned in 15 of 27 patients. In 10 patients, the anastomosis method was changed from stapled to hand-sewn according to the no-patch test results (60%), positivity for multiple metals (20%), positivity for staples (10%), and surgeon's judgment (10%). No complications and abnormal colonoscopy findings were found to be associated with stapled anastomosis/suturing. CONCLUSION: The patch test is useful for selecting an optimal anastomosis method for patients with suspected metal allergy.

[A Case of Cecum Cancer with Lymph Node Metastasis and Invasion in the Superior Mesenteric Vein Treated with Combined SMV Resection and Reconstruction].

The patient was a 77-year-old woman. She visited her family doctor with a complaint of bloody stools, and was pointed out a Type 3 colon cancer in the cecum with a colonoscopy. In addition, an enlarged lymph node(#203)was found on the right side of the superior mesenteric vein(SMV). Laparoscopic surgery was initiated, and when the patient was moved to vascular processing, a firm adhesion of the lymph node(#203)was observed on the right side of the SMV. A small laparotomy was added, and a partial combined resection of the SMV was performed en bloc to complete the ileal resection. Histopathological findings showed T4b(transverse colon)N3M0, pStage Ⅲc, and metastatic lymph node(#203)showed evidence of invasion to the SMV. Adjuvant chemotherapy was administered, but lung metastases appeared 4 months and liver metastasis appeared 29 months after surgery. The patient was transferred to a different hospital for best supportive care(BSC)at 34 months after surgery.

[A Case of Recurrence in the Abdominal Wall and Perineal Region of Rectal Cancer Successfully Treated with Minimally Invasive Surgery and Radiation Therapy].

Local recurrence after rectal cancer surgery is often difficult to treat because there are few effective treatments. In this study, we report a case of parastomal and perineal recurrence after Miles' surgery in an elderly patient who had a favorable outcome after laparoscopic surgery and radiation therapy. Our results suggest that a combination of minimally invasive treatment may be effective in elderly patients and after polysurgery.

[A Case Report for Peritoneal Recurrences by Laparoscopic Surgery after Colorectal Cancer Resection].

We report a cases report of colorectal cancer who underwent repeated resection for peritoneal recurrences by laparoscopic surgery. In 2013, a 70-year-old woman diagnosed with an ascending colon cancer underwent laparoscopic right hemicolectomy. The pathological diagnosis was tub2, pT4aN1M0, Stage Ⅲb. Postoperative adjuvant chemotherapy(uracil and tegafur/Leucovorin)was administered. PET-CT performed at 25 months after the surgery because of CEA elevation. It revealed a peritoneal recurrence in the pouch of Douglas. The following peritoneal recurrences were removed by laparoscopic Hartmann's procedure. Chemotherapy(5-fluorouracil/levofolinate/oxaliplatin/bevacizumab)was administered 11 courses and after that chemotherapy(5-fluorouracil/levofolinate/bevacizumab)was administered 6 courses. PET-CT performed 37 months after the second surgery revealed a peritoneal recurrence near the right ovary in the pouch of Douglas. The following peritoneal recurrences was removed. Chemotherapy(tegafur/gimeracil/oteracil/bevacizumab)was administered 11 courses. The long-term survival has been continued for 7 years and 7 months after first operation. It was considered that laparoscopic surgery for peritoneal recurrence in colorectal cancer is contributed to one of the surgical procedures in selected patients.

[A Case Report of a Giant GIST Markedly Responsive to Neoadjuvant Chemotherapy with Imatinib Mesylate].

Male in his 50s complaining of abdominal pain was referred to our hospital. Abdominal CT scan showed a giant tumor which had diameter of approximately 50 mm in lower rectum. A biopsy specimen was positive for CD34 and c-kit. Based on these findings, it was diagnosed as gastrointestinal stromal tumor(GIST). We treated the patient with neoadjuvant therapy using imatinib mesylate(IM)to reduce the tumor size and to avoid the extensive surgery. The patient started to take IM at a daily dose of 400 mg. After 3 months, CT and MRI revealed that the tumor size decreased(40% reduction). We performed the robot assisted intersphincteric resection(ISR). Although it has been 28 months since the surgery, there are no obvious signs of recurrence. A patient diagnosed with giant GIST could avoid an extensive surgery due to neoadjuvant therapy with IM.

Effectiveness of negative pressure wound therapy for the wound of ileostomy closure: a multicenter, phase II randomized controlled trial.

BACKGROUND: The American Society of Surgery and American Society for Surgical Infections issued guidelines for surgical site infections (SSIs) in December 2016. These guidelines recommend a purse-string suture (PSS) for stoma closure as it facilitates granulation and enables open wound drainage. This study investigated the effect of using negative pressure wound therapy (NPWT) along with standard PSS and aimed to determine the optimal period of NPWT use. METHODS: The patients were divided into three groups as follows: Group A, postoperative wound management alone with gauze exchange as the representative of conventional PSS; Group B, the performed management was similar to that of Group A plus NPWT for 1 week; and Group C, the performed management was similar to that of Group A plus NPWT for 2 weeks. Regarding objective measures, the wound reduction rate was the primary outcome, and the incidence of SSIs, length of hospital stay, and wound healing duration were the secondary outcomes. RESULTS: In total, 30 patients (male: 18, female: 12) were enrolled. The average age was 63 (range: 43-84) years. The wound reduction rate was significantly higher in Group B than in Group A on postoperative days (PODs) 7 (66.1 vs. 48.4%, p = 0.049) and 10 (78.6 vs. 58.2%, p = 0.011), whereas no significant difference was observed on POD 14. Compared with Group A, Group C (POD 7: 65.9%, POD 10: 69.2%) showed an increase in the wound reduction rate on POD 7, although the difference was not significant (p = 0.075). SSIs were observed in Groups B (n = 2) and C (n = 2) (20%) but not in Group A (0%). CONCLUSIONS: The most effective duration of NPWT use for ileostomy closure with PSS in terms of the maximum wound reduction rate was from PODs 3 to 10. However, NPWT did not shorten the wound healing duration. NPWT may reduce the wound size but should be used with precautions for SSIs. The small sample size (30 cases), the use of only one type of NPWT system, and the fact that wound assessment was subjective and not blinded were the limitations of this study. Further studies are needed to confirm our findings. TRIAL REGISTRATION: UMIN Clinical Trials Registry; UMIN000032174 (10/04/2018).

[A Case of Good Quality of Life(QOL)and Favorable Response to Transarterial Chemoembolization(TACE)against Synchronous Multiple Liver Metastases].

We report a case of good quality of life(QOL)and favorable response to transarterial chemoembolization(TACE)against synchronous multiple liver metastases. An 85-year-old man was admitted to our hospital because of melena. Colonoscopy showed multiple type 2 tumors in the sigmoid colon and upper rectum. CT and EOB-MRI examinations revealed that there were multiple liver metastases. Because of his age and surgical stress, he underwent a laparoscopic Hartmann's procedure. After the resection of the primary tumor, he received tegafur/uracil for his liver metastases. However, he discontinued receiving the drugs 2 weeks later because of the development of adverse events. Instead of systemic chemotherapy, he chose to undergo TACE. He underwent TACE with irinotecan and HepaSphereTM(BioSphere Medical)8 times for his multiple liver metastases. Consequently, all multiple liver metastases disappeared. Therefore, TACE may be useful for patients who are not suitable for systemic chemotherapy.

Endoscopic Submucosal Dissection Decreases Additional Colorectal Resection for T1 Colorectal Cancer.

BACKGROUND There are 3 methods of treating T1 colorectal cancer (T1 CRC), which include endoscopic resection, endoscopic resection followed by additional colorectal resection, and surgical resection. In this retrospective study, changes in the management of T1 CRC after introduction of endoscopic submucosal dissection (ESD) were investigated by comparison with the 10-year period before introduction of ESD. MATERIAL AND METHODS During a 20-year period from 1996 to 2015, 835 patients with T1 CRC were treated, including 331 patients before introduction of ESD (Group A) and 504 patients after introduction of ESD (Group B). Clinicopathological findings and treatment methods were compared between these 2 groups. RESULTS As the initial treatment, endoscopic treatment was performed in 185 patients (55.9%) in Group A and 288 (57.1%) in Group B. In Group B, ESD was performed in 161 patients (55.9%), accounting for more than half of the T1 CRC patients receiving endoscopic treatment. In Groups A and B, observation after endoscopic resection was selected for 54.2% and 67.3% of T1a patients, respectively (p=0.04). A similar trend was noted for T1b patients, and there was no significant difference of the treatment approach. Among all T1 CRC patients, the percentage undergoing observation after endoscopic resection was significantly higher in Group B than in Group A (34.3% vs. 26.9%, p=0.02), and the percentage of patients undergoing additional colorectal resection was significantly lower in Group B (22.8% vs. 29.0%, p=0.04). CONCLUSIONS After introduction of ESD, it was performed in more than half of all patients with T1 CRC undergoing endoscopic treatment. The percentage of patients undergoing observation following endoscopic resection of T1 CRC increased after introduction of ESD.

[A Study of Treatment for Pathological T1(SM)Colorectal Cancer Patients after Endoscopic Resection at Our Department].

Approximately 10% of pathological T1(SM)colorectal cancer patients develop lymph node metastases. Therefore additional colectomy with lymph node dissection is recommended when it applies to the specific criteria in the current JSCCR guidelines. However, additional colectomy would not be done in some cases, because surgery is too invasive for some patients. Endoscopic treatment(ESD or EMR)for T1(SM)cancer was performed in 324 cases between 2008 and 2016. Of those, 231 cases had satisfied the criteria for additional colectomy. Among them, 74 cases(32.0%)did not undergo, and additional colectomy(+)groupwas 153 cases(66.2%). Between the 2 groups, no difference in prognosis could be found. We considered there was no difference, because the prognosis of SM cancer is relatively good. In consideration of patient background, the treatment policy has to be chosen according to feasibility.

[A Case of Pelvic Metastasis of Rectal Cancer That Developed Ten Years after Curative Resection].

We report a case of pelvic metastasis of rectal cancer that developed 10 years after curative resection. An 81-year-old woman underwent intersphincteric resection for lower rectal cancer 10 years previously. The tumor was pathologically diagnosed as T2N0M0, Stage Ⅰ. Nine years after the curative resection, serum carcinoembryonic antigen(CEA)levels were slightly elevated, but no recurrence was found on computed tomography(CT). Eleven months after CT, serum CEA levels elevated to 15.9 ng/mL. Pelvic metastasis in the piriformis muscle was detected on positron emission tomography(PET)-CT. Following CT-guided biopsy, she was pathologically diagnosed with metastatic rectal cancer. Radiotherapy (60 Gy/30 Fractions) was administered. Ten months after radiotherapy, PET-CT revealed no relapse in the pelvis with lung metastases.

Repeated laparoscopic resection of extra-regional lymph node metastasis after laparoscopic radical resection for rectal cancer.

Here, we report a case of repeated laparoscopic resection of extra-regional lymph node metastases in a patient after laparoscopic surgery for rectal cancer. A 72-year-old woman was diagnosed with upper rectal cancer and underwent laparoscopic low anterior resection and D3 dissection. The pathological stage was considered as T3, N2b, M0, Stage IIIC. Six months after the operation, positron emission tomography-computed tomography (PET-CT) showed fluorodeoxyglucose (FDG) accumulation in the infra-renal para-aortic lymph nodes (PALNs). Systemic chemotherapy was administered; however, chemotherapy was discontinued due to hemoptysis related to her pulmonary disease. Therefore, we performed laparoscopic PALN resection. Pathologically, one lymph node was diagnosed with a metastasis. Three months after the second operation, PET-CT identified FDG accumulation in the left lateral pelvic lymph nodes (LPLNs) and a PALN. Laparoscopic LPLN dissection and PALN resection through minilaparotomy were performed. Pathologically, lymph node metastases were diagnosed in both fields. Sixteen months after the 3rd operation, there is no recurrence.

A case of total laparoscopic sigmoidectomy involving the use of needle forceps and transanal specimen extraction for sigmoid colon cancer.

A 76-year-old male underwent endoscopic mucosal resection for a stage T1 tumour of the sigmoid colon. We performed laparoscopic sigmoidectomy through 5 ports using needlescopic instruments. The resected specimen was extracted from the abdominal cavity transanally. After attaching an anvil to the sigmoidal stump, the rectal stump was reclosed using an endoscopic linear stapler, and then, colorectal anastomosis was conducted using the double stapling technique. Performing transanal specimen extraction using needlescopic forceps improves aesthetic outcomes and reduces post-operative pain and the risk of abdominal incisional hernias. This method is an easy to introduce a form of reduced-port surgery because of its feasibility and conventional port arrangement. Hence, we consider that it is an option for minimally invasive surgery.

Clinical pathway to discharge 3 days after colorectal endoscopic submucosal dissection.

BACKGROUND AND AIM: Colorectal endoscopic submucosal dissection (ESD) is a useful treatment method; however, no index has been established for time for patient to start food ingestion or be discharged after ESD. We investigated the potential of a clinical pathway in which patients started food ingestion on day 2 after ESD and were discharged on day 3. METHODS: A total of 382 patients underwent colorectal ESD between 2006 and 2012. A flow chart of a clinical pathway was prepared based on the data obtained, with the aim of shortening hospital stay after ESD. RESULTS: Mean duration of postoperative hospital stay in the 382 patients was 5.3 ± 1.8 days. The most common cause of extended hospital stay was abnormal blood test finding, as detected in 50 patients in group C (n = 131; 38.2%), followed by careful course observations, as noted in 48 patients in group C (n = 131; 36.6%). Regarding procedural accidents as a result of ESD, intraoperative perforation occurred in 15 patients (3.9%) and post-ESD bleeding in seven patients (1.8%), which extended the hospital stay. Food ingestion was started on day 2 when no abnormality was noted during ESD or in physical and imaging findings or blood tests on day 1. In the 86 patients who underwent the prepared clinical pathway as a validation study, 68 (79.0%) were discharged on day 3. Duration of postoperative hospital stay was 3.4 ± 1.2 days. CONCLUSION: Discharge may be possible 3 days after ESD when no abnormalities are noted during ESD or on post-ESD day 1.

[A case of cecum colon cancer with lymph node metastasis successfully treated with XELOX plus bevacizumab].

A 65-year-old woman with a history of constipation presented at our hospital and was subsequently diagnosed with advanced cecum cancer. We performed laparoscopic right hemicolectomy in January 2009, with pathological findings reveal- ing the presence of Stage III b (pT3, pN3, cM0, Cur A) disease. The patient was treated with a uracil/tegafur plus Leucovorin (UFT/LV) adjuvant chemotherapy regimen for six months. In June 2010, bold examination indicated an elevated level of tumor marker CA19-9. Computed tomography (CT) and positron emission tomography (PET)/CT revealed Virchow's and para-aortic lymph node metastasis. Therapy with XELOX and bevacizumab (Bmab) was administered and continued for 10 cycles. Capecitabine+Bmab treatment was also administered for 11 courses due to an adverse event of peripheral neuropathy. Follow-up revealed both the Virchow's and para-aortic lymph node metastasis had disappeared upon completion of treatment. In November, 2011 the patient was considered to have achieved a clinical complete response (CR) and continues to be followed with no further disease progression.

Clinicopathological features and prognosis of primary small bowel adenocarcinoma: a large multicenter analysis of the JSCCR database in Japan.

BACKGROUND: The clinicopathological features and prognosis of primary small bowel adenocarcinoma (PSBA), excluding duodenal cancer, remain undetermined due to its rarity in Japan. METHODS: We analyzed 354 patients with 358 PSBAs, between January 2008 and December 2017, at 44 institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum. RESULTS: The median age was 67 years (218 males, 61.6%). The average tumor size was 49.9 (7-100) mm. PSBA sites consisted of jejunum (66.2%) and ileum (30.4%). A total of 219 patients (61.9%) underwent diagnostic small bowel endoscopy, including single-balloon endoscopy, double-balloon endoscopy, and capsule endoscopy before treatment. Nineteen patients (5.4%) had Lynch syndrome, and 272 patients (76.8%) had symptoms at the initial diagnosis. The rates for stages 0, I, II, III, and IV were 5.4%, 2.5%, 27.1%, 26.0%, and 35.6%, respectively. The 5-year overall survival rates at each stage were 92.3%, 60.0%, 75.9%, 61.4%, and 25.5%, respectively, and the 5-year disease-specific survival (DSS) rates were 100%, 75.0%, 84.1%, 59.3%, and 25.6%, respectively. Patients with the PSBA located in the jejunum, with symptoms at the initial diagnosis or advanced clinical stage had a worse prognosis. However, multivariate analysis using Cox-hazard model revealed that clinical stage was the only significant predictor of DSS for patients with PSBA. CONCLUSIONS: Of the patients with PSBA, 76.8% had symptoms at the initial diagnosis, which were often detected at an advanced stage. Detection during the early stages of PSBA is important to ensure a good prognosis.

Outcomes of Metastatic and Unresectable Small Bowel Adenocarcinoma in Japan According to the Treatment Strategy: A Nationwide Observational Study.

PURPOSE: Limited information is available regarding the characteristics and outcomes of stage IV small bowel adenocarcinoma (SBA) in Japan. This study examined the clinical and pathological characteristics and outcomes according to the treatment strategies in patients with stage IV SBA. METHODS: This retrospective observational study used the data of patients with jejunal or ileal adenocarcinoma collected by the Small Bowel Malignant Tumor Project of the Japanese Society for Cancer of the Colon and Rectum. Descriptive statistics were expressed as the mean (standard deviation) or median (range). Survival analysis was performed using Kaplan-Meier curves and pairwise log-rank tests. RESULTS: Data from 128 patients were analyzed. The treatment strategies were chemotherapy alone (26 of 128, 20.3%), surgery alone (including palliative surgery; 21 of 128, 16.4%), surgery + chemotherapy (74 of 128, 57.8%), and best supportive care (7 of 128, 5.5%). The median (range) overall survival was 16 (0-125) months overall, and 11 (1-38) months, 8 (0-80) months, 18 (0-125) months, and 0 (0-1) months for the chemotherapy, surgery, surgery + chemotherapy, and best supportive care groups, respectively. Three main categories of chemotherapeutic regimen were used: a combination of fluoropyrimidine and oxaliplatin (F + Ox), fluoropyrimidine and irinotecan (F + Iri), and single-agent fluoropyrimidine. Among patients treated with chemotherapy, the median (range) OS was 16 (1-106) months overall, and 17 (1-87) months, 29 (7-39) months, and 16 (1-106) months in patients treated with fluoropyrimidine, F + Iri, and F + Ox, respectively. CONCLUSION: Patients treated with surgery, chemotherapy, or both had a better prognosis than those who received best supportive care. Among patients who received chemotherapy, survival did not differ according to the chemotherapeutic regimen.

Positive Circumferential Resection Margin in Rectal Cancer Is a Robust Predictor of Poor Long-term Prognosis With Clinicopathological Bias Between Groups Compensated by Propensity-score Matching Analysis.

BACKGROUND/AIM: Circumferential resection margin (CRM) is the most reliable predictor of local and distant recurrence in locally-advanced rectal cancer (LARC). The present study was conducted to compare the long-term outcomes between CRM (+) and (-) groups using propensity-score (PS) matching analysis to compensate for bias between groups. PATIENTS AND METHODS: Of 563 consecutive patients with Stage II/III rectal cancer who were treated surgically with curative-intent at Juntendo University Hospital between Jan 1989 and Mar 2018, 412 patients were enrolled retrospectively in the study. The patients were divided into a CRM (+) group (n=21; 5.1%) and a CRM (-) group (n=391; 94.9%). RESULTS: In the entire cohort, recurrence-free survival (RFS), local recurrence-free survival (LRFS), non-local recurrence-free survival (NLRFS), and cancer-specific survival (CSS) were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group. Univariate analysis demonstrated patients in the CRM (+) group had significantly larger primary tumors (p=0.02), more frequently had open surgery (p=0.009), had an abdominoperineal resection (APR) procedure (p=0.01) and a T4 primary tumor (p<0.0001). After PS matching analysis, in the propensity-matched cohort, RFS, LRFS, NLRFS and CSS were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group. CONCLUSION: PS matching analysis demonstrated that RFS, LRFS, NLRFS, and CSS were significantly worse among patients in the CRM (+) group compared with those in the CRM (-) group. The present results indicate that CRM (+) is a robust predictor of long-term outcome of LARC, independent of tumor size.

Local recurrence of submucosal invasive colorectal cancer after endoscopic submucosal dissection revealed by copy number variation.

We report a case in which analysis of copy number variation revealed local recurrence of submucosal invasive colorectal cancer after curative endoscopic submucosal dissection (ESD). An 86-year-old man with a history of abdominoperineal resection of the rectum for rectal cancer underwent resection with ESD for early-stage sigmoid cancer 5 cm away from the stoma opening. At the same time, ileocecal resection was performed for advanced cecal cancer. Twelve months after ESD, advanced cancer occurred in the area of the ESD lesion. It was unclear if the cancer was a local recurrence after ESD, implantation of cecal cancer, or a new lesion. Copy number variation analysis performed for the three lesions revealed that the new lesion originated from residual tumor cells from ESD and was unlikely to be cecal cancer.