Landscape of homologous recombination deficiency in gastric cancer and clinical implications for first-line chemotherapy.

BACKGROUND: Homologous recombination deficiency (HRD) is one of the crucial hallmarks of cancer. It is associated with a favorable response to platinum-based chemotherapy. We explored the distinctive clinicopathological features of gastric cancer (GC) with HRD and the clinical significance of HRD in platinum-based first-line chemotherapy for unresectable metastatic GC. METHODS: We enrolled 160 patients with GC in this study. Their tumor samples were subjected to genomic profiling utilizing targeted tumor sequencing. HRD was defined as the presence of alterations in any of 16 HR genes (BARD1, BLM, BRCA1, BRCA2, BRIP1, MRE11A, NBN, PALB2, PARP1, POLD1, RAD50, RAD51, RAD51C, RAD51D, WRN, and XRCC2). The clinicopathological features and treatment outcomes of first-line chemotherapy for unresectable metastatic GC were compared between HRD and non-HRD groups. RESULTS: Forty-seven patients (29.4%) were classified into the HRD group. This group had a significantly lower proportion of macroscopic type 3 or 4 tumors and higher TMB than the non-HRD group. Among patients who underwent platinum-based first-line chemotherapy, the HRD group had a greater response rate and longer progression-free survival after treatment (median 8.0 months vs. 3.0 months, P = 0.010), with an adjusted hazard ratio of 0.337 (95% confidence interval 0.151-0.753). HRD status was not associated with treatment outcomes in patients who did not undergo platinum-based chemotherapy. CONCLUSIONS: Low proportion of macroscopic type 3 or 4 tumors and a high TMB are distinctive features of GC with HRD. HRD status is a potential predictive marker in platinum-based first-line chemotherapy for unresectable metastatic GC.

Macroscopic type is implicated in the prognostic impact of initial chemotherapy on peritoneal lavage cytology-positive gastric cancer with no other noncurative factors.

BACKGROUND: Initial chemotherapy (Initial-C) followed by surgery is a promising treatment strategy for peritoneal lavage cytology-positive gastric cancer (CY1 GC) with no other noncurative factors. The aim of this study was to investigate the survival advantage of Initial-C compared to initial surgery (Initial-S) for this disease according to the macroscopic type, which was associated with prognosis and the efficacy of chemotherapy in GC. METHODS: One hundred eighty-nine patients who were diagnosed with CY1 GC with no other noncurative factors at four institutions from January 2007 to December 2018 were enrolled. The patients were divided into a macroscopic type 4 group (N = 48) and a non-type 4 group (N = 141). The influence of initial treatment on overall survival (OS) in each group was evaluated. RESULTS: In the type 4 group, the 5-year OS rates of Initial-C (N = 35) and Initial-S (N = 13) were 11.6% and 0%, respectively (P = 0.801). The multivariate analysis could not show the survival advantage of Initial-C. In the non-type 4 group, the 5-year OS rates of Initial-C (N = 41) and Initial-S (N = 100) were 48.4% and 29.0%, respectively (P = 0.020). The multivariate analysis revealed that Initial-C was independently associated with prolonged OS (hazard ratio, 0.591; 95% confidence interval, 0.375-0.933: P = 0.023). CONCLUSIONS: Initial-C improves the prognosis of non-type 4 CY1 GC with no other noncurative factors. On the other hand, further development of effective chemotherapeutic regimens and innovative treatment strategies are required for type 4 CY1 GC.

Risk factors for death from other diseases after curative gastrectomy and lymph node dissection for gastric cancer.

BACKGROUND: Recent advances in treatment are expected to bring a cure to more patients with gastric cancer (GC). Focusing on the risk of death from other diseases (DOD) has become a crucial issue in patients cured of GC. The aim of this study was to elucidate the risk factors for DOD in patients who underwent curative gastrectomy with lymph node dissection for GC. METHODS: We enrolled 810 patients who underwent curative gastrectomy with lymph node dissection for GC from January 1990 to December 2014 and had no recurrence or death of GC until December 2019. We investigated the risk factors for DOD defined as death excluding death from a malignant neoplasm, accident, or suicide after gastrectomy, focusing on the perioperative characteristics at gastrectomy. RESULTS: Among 315 deaths from any cause, 210 died from diseases other than malignancy, accidents and suicide. The leading cause of DOD was pneumonia in 54 patients (25.7%). The actual survival period in 167 patients (79.5%) with DOD was shorter than their estimated life expectancy at gastrectomy. Multivariate analysis revealed that a high Charlson Comorbidity Index score (score 1-2: hazard ratio [HR] 2.192, 95% confidence interval [CI] 1.713-2.804, P < 0.001 and score ≥ 3: HR 4.813, 95% CI 3.022-7.668, P < 0.001), total gastrectomy (HR 1.620, 95% CI 1.195-2.197, P = 0.002) and the presence of postoperative complications (HR 1.402, 95% CI 1.024-1.919, P = 0.035) were significant independent risk factors for DOD after gastrectomy for GC, in addition to age of 70 years or higher, performance status of one or higher and body mass index less than 22.0 at gastrectomy. CONCLUSIONS: Pneumonia is a leading cause of DOD after curative gastrectomy and lymph node dissection for GC. Paying attention to comorbidities, minimizing the choice of total gastrectomy and avoiding postoperative complications are essential to maintain the long-term prognosis after gastrectomy.

Conversion surgery for stage IV gastric cancer: a multicenter retrospective study.

BACKGROUND: Recent improvements in systemic chemotherapy have provided an opportunity for patients with stage IV gastric cancer (GC) to undergo conversion surgery (CS). The aim of this study was to evaluate the long-term outcomes of patients who underwent CS and to elucidate the prognostic factors for CS in stage IV GC. METHODS: A total of 79 patients who underwent CS with the aim of R0 resection for stage IV GC at six institutions from January 2008 to July 2019 were enrolled. We retrospectively reviewed the clinicopathological data and prognosis. RESULTS: Of the 79 patients, 23 (31.1%) had initially resectable disease (IR) before chemotherapy, defined as positive for cancer on peritoneal cytology (CY1), resectable hepatic metastasis, or para-aortic lymph node No. 16a2/b1 metastasis. Of the 56 remaining patients with primary unresectable disease, 39 had peritoneal dissemination. R0 resection was accomplished in 63 patients (79.7%). The 3-year OS rates for patients with IR and unresectable disease were 78.3% and 44.5%, respectively. Multivariate analysis showed that IR (P = 0.014) and R0 (P = 0.014) were statistically significant independent prognostic factors for favorable OS. Among patients with peritoneal dissemination alone, OS was significantly better for patients with R0 resection than for patients with R1/2 resection, with the 3-year OS rates of 65.5% and 23.1%, respectively (P = 0.011). CONCLUSIONS: CS is a treatment option for selected patients with stage IV GC. Patients with IR and patients who achieve R0 resection may obtain a survival benefit from CS.

[A Case of Unresectable Advanced Gastric Cancer Resected by Conversion Surgery after Trastuzumab Combination Chemotherapy].

A 74-year-old man presented to our hospital with a mass in the left supraclavicular fossa. He was diagnosed with advanced gastric cancer with liver metastasis and left supraclavicular and para-aortic lymph node metastasis, cT3N2M1 (LYM, HEP), cStage Ⅳ(the Union for International Cancer Control, TNM 7th edition). He received a total of 3 courses of S- 1 plus cisplatin therapy. Since he developed adverse reactions such as anorexia, renal dysfunction, and thrombocytopenia and the tumor was HER2-positive, he received 25 courses of capecitabine, cisplatin, and trastuzumab chemotherapy. Three years and 2 months after the first chemotherapy, remarkable tumor reduction was observed. The patient then underwent radical distal gastrectomy with D2 lymphadenectomy, and R0 resection was achieved. The histopathological diagnosis was ypT1aN0M0, ypStage ⅠA. Chemotherapy with trastuzumab may improve the long-term prognosis of HER2-positive Stage Ⅳ gastric cancer if the disease is controlled and radical resection can be achieved.

Clinical Utility of ypTNM Stage Grouping in the 8th Edition of the American Joint Committee on Cancer TNM Staging System for Esophageal Squamous Cell Carcinoma.

BACKGROUND: The 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging system provided a specific 'ypTNM' stage grouping for patients with esophageal cancer. OBJECTIVE: This study aimed to evaluate the clinical utility of the AJCC 8th edition ypTNM stage grouping for patients with esophageal squamous cell carcinoma (ESCC). METHODS: We enrolled 152 patients with ESCC who underwent surgery after neoadjuvant cisplatin plus 5-fluorouracil (CF) therapy between June 2005 and December 2011. ypStage was evaluated according to the AJCC 7th and 8th editions. Predictive performance for disease-specific survival (DSS) and overall survival (OS) was compared between both editions. The prognostic significance of ypTNM stage grouping was evaluated using univariate and multivariate analyses. RESULTS: Revision of the AJCC 7th edition to the 8th edition was associated with a change in ypStage in 96 patients (63.2%). The AJCC 8th edition revealed a better predictive performance than the 7th edition in terms of DSS (Akaike's information criterion [AIC] 499 vs. 513; Bayesian information criterion [BIC] 505 versus 519; concordance index [C-index] 0.725 versus 0.679) and OS (AIC 662 vs. 674; BIC 669 vs. 681; C-index 0.662 vs. 0.622). On univariate and multivariate analyses, ypStage in the 8th edition was an independent prognostic factor for both DSS and OS. CONCLUSIONS: ypTNM stage grouping in the AJCC 8th edition provided a better predictive performance for DSS and OS than that in the 7th edition. ypStage in the 8th edition was the most reliable prognostic factor for ESCC patients who underwent surgery after neoadjuvant CF therapy.

Anatomic location of residual disease after initial cholecystectomy independently determines outcomes after re-resection for incidental gallbladder cancer.

PURPOSE: This study aimed to elucidate the impact of anatomic location of residual disease (RD) after initial cholecystectomy on survival following re-resection of incidental gallbladder cancer (IGBC). METHODS: Patients with pT2 or pT3 gallbladder cancer (36 with IGBC and 171 with non-IGBC) who underwent resection were analyzed. Patients with IGBC were classified as follows according to the anatomic location of RD after initial cholecystectomy: no RD (group 1); RD in the gallbladder bed, stump of the cystic duct, and/or regional lymph nodes (group 2); and RD in the extrahepatic bile duct and/or distant sites (group 3). RESULTS: Timing of resection (IGBC vs. non-IGBC) did not affect survival in either multivariate or propensity score matching analysis. RD was found in 16 (44.4%) of the 36 patients with IGBC; R0 resection following re-resection was achieved in 32 patients (88.9%). Overall survival (OS) following re-resection was worse in group 3 (n = 7; 5-year OS, 14.3%) than in group 2 (n = 9; 5-year OS, 55.6%) (p = 0.035) or in group 1 (n = 20; 5-year OS, 88.7%) (p < 0.001). There was no survival difference between groups 1 and 2 (p = 0.256). Anatomic location of RD was independently associated with OS (group 2, HR 2.425, p = 0.223; group 3, HR 9.627, p = 0.024). CONCLUSION: The anatomic location of RD independently predicts survival following re-resection, which is effective for locoregional disease control in IGBC, similar to resection for non-IGBC. Not all patients with RD have poor survival following re-resection for IGBC.

[A Case of Long-Term Survival after Resection of Pancreatic Ductal Adenocarcinoma with Para-Aortic Lymph Node Metastasis].

The patient was a 64-year-old man with diagnosis of pancreatic head cancer. Initially, abdominal CT showed pancreatic head tumor with bile duct invasion and no distant metastases including para-aortic lymph nodes(PALN). Although, subtotal stomach-preserving pancreatoduodenectomy(SSPPD)and PALN sampling was performed, intraoperative frozen section examination revealed PALN metastasis. He had chronic kidney disease and was unsuitable for standard chemotherapy, SSPPD and PALN dissection was performed instead of standard chemotherapy. Histopathological examination of the resected specimens revealed invasive ductal carcinoma in the pancreatic head region and 11 nodes out of the 17 dissected PALN. Adjuvant chemotherapy with S-1 was performed. 22 months after surgery, intraabdominal lymph nodes metastasis and lung metastasis was found. 24 months after surgery, palliative radiation therapy at a dose of 40 Gy was performed. Systemic chemotherapy with gemcitabine alone was performed, but he was dead 67 months after the initial therapy.

[A Case of HER2-Positive Recurrent Breast Cancer and Liver Metastases of GIST Treated with Combined Anti-HER2 Therapy and Imatinib].

A 70-year-old female with liver metastases from gastrointestinal stromal tumor(GIST)that were found 3 months after partial gastrectomy for the primary GIST underwent Auchincloss operation for left breast cancer with ipsilateral axillary lymph node metastases. The diagnosis was microinvasive ductal cancer that was pT1miN1M0, pStage ⅡA, hormone receptor negative, and HER2 positive. Given the impact of this cancer on the prognosis of liver metastases of GIST, imatinib therapy, but not adjuvant chemotherapy, was started promptly for breast cancer after surgery. Four months after the surgery, left subclavian lymph node recurrence of breast cancer was found. Since the liver metastases of GIST had been stable, imatinib was discontinued, and paclitaxel and anti-HER2 therapy were administered. After confirming tolerability, imatinib was carefully added in combination. Because the lymph nodes shrank and liver metastases of GIST were stable, both anti-HER2 therapy and imatinib were continued. There are few reports of combined chemotherapy for synchronous double cancer, and we report our experience in which careful treatment was required.

Long-Term Trends in Respiratory Function After Esophagectomy for Esophageal Cancer.

BACKGROUND: Esophagectomy for esophageal cancer is known to lead to deterioration in respiratory function (RF). The aim of this study was to assess long-term trends in RF after esophagectomy and the impact of different operative procedures. METHODS: A total of 52 patients with thoracic esophageal cancer who were scheduled for esophagectomy from 2003 to 2012 were enrolled. We prospectively evaluated patients for vital capacity (VC), forced expiratory volume in 1 s (FEV1.0), and 6-min walk distance (6MWD) before and after esophagectomy at 3, 6, 12, 24, and 60 mo. RESULTS: Patients had mostly recovered their VC and FEV1.0 after 12 mo. After that point, VC and FEV1.0 declined again, reaching levels lower than baseline at 60 mo, with a median change ratio of 0.85 and 0.86, respectively. Although the 6MWD after open esophagectomy declined, patients treated with transhiatal esophagectomy and minimally invasive esophagectomy maintained above baseline levels throughout the follow-up period. Furthermore, we identified transhiatal esophagectomy (odds ratio [OR] = 0.03, 95% confidence interval [CI] 0.002-0.43, P = 0.01) and minimally invasive esophagectomy (OR = 0.14, 95% CI 0.02-0.94, P = 0.04) as favorable factors and postoperative pulmonary complication (OR = 9.14, 95% CI 1.22-68.6, P = 0.03) as an unfavorable factor for RF after 12 mo. Operative procedures had no significant impact on RF after 60 mo. CONCLUSIONS: Our results support the notion that RF does not recover to the baseline level, and operative procedures have no significant impact on RF at late phase after esophagectomy.

[A Case of a"Watch and Wait Therapy"Approach after Preoperative Chemoradiotherapy for Rectal Cancer Accompanied by Severe Emphysema].

A 72-year-old man was referred to our hospital for treatment for rectal cancer. Digital rectal examination and colonoscopy revealed a 4 cm tumor located at the anterior rectal wall 5 cm away from the anal verge, and pathological examination confirmed that the tumor was adenocarcinoma. A computed tomography scan detected neither regional lymph node metastasis nor distant metastasis. Hence, he was diagnosed with cT3N0M0, cStage Ⅱa rectal cancer. The preoperative general examination revealed bradyarrhythmia and severe emphysema, and he was considered to be high risk for general anesthesia. After placement of a pacemaker, preoperative capecitabine-based chemoradiotherapy(CRT)(50.4 Gy in 28 fractions of 1.8 Gy each)was implemented. The digital rectal examination and imaging evaluation 4 weeks after preoperative CRT revealed that the tumor disappeared, and pathological examination showed no malignant findings. Considering the risks of general anesthesia, the"watch and wait therapy"approach was adopted with sufficient informed consent. At present, 15 months after preoperative CRT, no evidence of regrowth or distant metastasis has been detected under rigorous follow- up evaluations.

[Amelanotic Malignant Melanoma of the Esophagogastric Junction-A Case Report].

A 73-year-old man presented with anemia, and gastroscopy showed a nonpigmented tumor in the esophagogastric junction. The result of the tumor biopsy initially suspected poorly differentiated adenocarcinoma. However, additional immunohistochemical examination revealed malignant melanoma. The final diagnosis was amelanotic malignant melanoma of the esophagogastric junction with adrenal and spinal metastasis. Although immunotherapy was performed, the patient died 132 days after diagnosis.

[Long-Term Survival after Surgery with Postoperative Chemotherapy for Perihilar Cholangiocarcinoma with Residual Invasive Carcinoma at Ductal Resection Margins-A Case Report].

A 64-year-old man with liver dysfunction was given a diagnosis of perihilar cholangiocarcinoma(Bismuth type Ⅳ). The tumor was predominantly right-sided and invaded to the bifurcation of the right and left portal veins. After confirming sufficient liver functional reserve and future liver remnant, the patient underwent extended right hepatectomy, extrahepatic bile duct resection, and portal vein resection and reconstruction. Intraoperative examination of frozen sections revealed the presence of residual invasive carcinoma on both the hepatic and duodenal sides of the ductal resection margins. However, we did not perform pancreaticoduodenectomy or additional resection of the margin-positive proximal bile duct considering the curability and invasiveness of these procedures. He received postoperative chemotherapy with biweekly gemcitabine plus cisplatin for 1 year, followed by gemcitabine monotherapy for 1 year, and S-1 monotherapy has been performed since then. He remains alive and well with no evidence of disease 63 months after surgery.

[A Case of High-Frequency Microsatellite Instability in Colorectal Cancer with MSH2 Mutation Detected Using Gene Panel Testing with a Next-Generation Sequencer].

Here, we report about a woman in her 30s who had peritoneal dissemination and multiple colon cancer with high-frequency microsatellite instability(MSI-H). Her father, paternal grandfather, and maternal grandmother had a history of colorectal cancer treatment. Thus, Lynch syndrome was suspected. We performed R0 resection for peritoneal dissemination and subsequent peritoneal dissemination. A 435-gene panel testing using a next-generation sequencer identified MSH2 and other mutations in the tumor. Hence, we speculated that she could have a germline mutation of MSH2, which causes Lynch syndrome. In the future, if she wishes to receive genetic counseling and undergo germline testing for variants to confirm the diagnosis of Lynch syndrome, we will perform them after receiving informed consent.

Phospho-Sphingosine Kinase 1 Expression in Lymphatic Spread of Esophageal Squamous Cell Carcinoma.

BACKGROUND: Lymphatic spread is the main mode of progression of esophageal squamous cell carcinoma (ESCC). Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid mediator, which produced by sphingosine kinase 1 (SphK1) activated by phosphorylation. The SphK1-S1P axis has a crucial role in lymphangiogenesis. However, the significance of phospho-SphK1 (pSphK1) in the progression of ESCC has not been fully investigated. MATERIALS AND METHODS: We evaluated pSphK1 expression in 92 surgically resected tumor tissues of ESCC by the immunohistochemistry. Fifty-nine (64%) patients with moderate or strong expression and 33 (36%) with negative or weak expression were classified in the pSphK1-high and pSphK1-low groups, respectively. RESULTS: Higher pathological N category (pN) was more frequently observed in the pSphK1-high group (P < 0.01). The median number of lymph node metastasis (pSphK1-high: 2 versus pSphK1-low: 0; P < 0.01), the proportion of patients with lymphatic invasion (69% versus 18%; P < 0.01) and that with intramural metastasis (27% versus 3%; P < 0.01) were significantly higher in the pSphK1-high group. The presence of lymphatic invasion (odds ratio [OR] 5.63; P < 0.01) and pN1-3 (OR 3.26; P = 0.04) were independently associated with high pSphK1 expression. The 5-y overall survival rate of the pSphK1-high group was significantly lower than that of the pSphK1-low group (50.8% versus 67.3%; P = 0.01). High pSphK1 expression was not identified as a significant independent prognostic factor. CONCLUSIONS: We provide the first evidence of the association between high expression of pSphK1 and both lymphatic spread and patient outcomes in ESCC.

[Digestive Surgery Intervention for Gynecological Malignant Tumor].

AIM: This study aimed to determine surgical outcomes in patients with gynecological cancers for whom surgery was performed by gynecologists and digestive surgeons. METHODS: Seventy-three patients who underwent surgery for a gynecological malignant tumor from January 2010 to December 2014 were included in this retrospective study. Data on the definitive diagnosis, operative procedures, postoperative complications, stoma settings, length of hospital stay, and prognosis was collected for each patient. RESULTS: The median age of this female-only cohort was 60 years. Emergency surgery was performed in 8(11.0%)patients. Ovarian cancer was diagnosed in 56(76.7%)patients, and among these patients, the clinical disease Stage was Ⅰ, Ⅱ, Ⅲ, and Ⅳ in 4, 4, 20, and 11 patients, respectively. Moreover, 17 patients had recurrent ovarian cancer. Intestinal resection with anastomosis was performed in 25(34.2%)patients. Stoma formation was performed in 22 (30.1%)patients, however no patient underwent stoma closure surgery in the current study. The median operative time was 252 minutes, and the median blood loss was 1,190 mL. Regarding postoperative complications, ileus, pelvic abscess, and anastomotic leakage developed in 6(8.2%), 4(5.5%), and 2(2.7%)patients, respectively. The postoperative median survival time in patients with ovarian cancer was 1,399 days. CONCLUSION: These results suggest that tumor debulking, including intestinal tract resection, may contribute to the prolonged prognosis of gynecological tumors, although stoma closure is difficult to perform.

[A Case of Esophageal Cancer Achieving a Pathological Complete Response after Preoperative Docetaxel, Cisplatin, and 5-Fluorouracil Therapy].

A 66-year-old man with middle thoracic esophageal squamous cell carcinoma with supraclavicular lymph node metastasis visited our hospital. He underwent 3 courses of preoperative chemotherapy with docetaxel, cisplatin, and 5-FU(DCF)with a clinically-determined partial response. Minimally-invasive esophagectomy with 3-fieldlymphad enectomy was subsequently performed. Histopathologic examination revealedno viable tumor cells in the resectedesophagus andsupraclavicular lymph node. DCF is a promising preoperative chemotherapy regimen for locally advanced esophageal cancer because of its higher complete response rate comparedto that for cisplatin plus 5-FU.

[A Case of Esophageal Primary Malignant Melanoma That Developed During the Follow-Up of Esophageal Melanocytosis].

A 78-year-old woman was endoscopically followed up for benign melanocytosis in the middle thoracic esophagus that was detected 3 years prior. She presented with chest tightness, and an endoscopic examination revealed a protruding tumor at the melanotic lesion. She was histologically diagnosedwith an esophageal primary malignant melanoma. Computedtomography showedno metastatic lesions. She underwent minimally invasive esophagectomy with 2-fieldlymphad enectomy. Immunotherapy with nivolumab is ongoing for liver metastasis, which developed1 year and6 months after esophagectomy. Careful follow-up for esophageal melanocytosis is important for early diagnosis of esophageal primary malignant melanoma.

[A Case of Long-Term Survival in a Patient with Advanced Rectal Cancer and Paraaortic and Lateral Lymph Node Metastases].

A 65-year-old woman was referred for further examination following positive results on a fecal occult blood test. Colonoscopy revealed type 0-Ⅱa cancer, with a lesion measuring 2 cm in diameter in the rectosigmoid colon, and type 5 cancer, with a lesion measuring 6 cm in diameter in the upper rectum. Computed tomography(CT)and positron emission tomography (PET)-CT revealed mesorectal lymph node metastases. Therefore, she was diagnosed with rectosigmoid colon cancer(Stage Ⅰ)and upper rectal cancer(Stage Ⅲa). However, PET-CT also revealed slight fluorodeoxyglucose uptake in the paraaortic and lateral lymph node lesions; hence, the possibility ofmetastasis could not be ruled out. Given that chemotherapy was restricted due to renal dysfunction, low anterior resection was performed as the first choice. Analysis of intraoperative frozen sections showed paraaortic and lateral lymph node metastases; thus, we performed lymph node dissection of these lesions. Pathological examination ofthe resected lymph nodes revealed that 21 of 37 lesions were cancer metastases. S-1 was administered as adjuvant chemotherapy for 5 months. Mediastinal lymph node metastases was suspected on chest CT 5 months and 3 years post-surgery; thus, panitumumab was administrated. These lymph nodes decreased in size immediately. Six years after the first surgery, the patient was well without any signs of recurrence.

[A Case of Pathological Complete Response with Neoadjuvant Chemotherapy for Advanced Rectal Cancer].

A 62-year-old man was admitted with complaints of bloody stool. Colonoscopy revealed a 5 cm diameter type 2 tumor in the lower rectum close to the anal canal. Tumor biopsy indicated a well-differentiated tubular adenocarcinoma. Computed tomography revealed locally advanced rectal cancer with mesorectal lymph node metastases(cT3N1P0M0, Stage Ⅲa, JSCCR 8th). The patient was treated with neoadjuvant chemotherapy(NAC)after transverse colostomy as an anus-preserving procedure. For the NAC, 12 courses of capecitabine plus oxaliplatin(CapeOX)and bevacizumab(BV)were administered. Colonoscopy after NAC revealed that the main tumor had considerably shrunk. No malignant tissues were found on biopsy. However, rectal wall thickness remained unchanged. Therefore, response evaluation for chemotherapy indicated partial response. Intersphincteric resection(ISR)with diverting loop ileostomy was performed as an anus-preserving surgical procedure. No remnant tumor in the rectum or lymph node metastases were found upon the pathological examination of resected specimens. Ileostomy closure was performed at 6 months post-ISR. At 12 months post-ISR, the patient was well and showed no signs of recurrence. This case demonstrated that NAC with CapeOX and BV can be a promising option for treating locally advanced lower rectal cancer and preserving the anus.