Primary adenocarcinoma arising from rectal implantation cyst after low anterior resection for rectal cancer 31 years previously.

Rectal implantation cysts can occur at anastomotic sites after low anterior resection (LAR) for rectal cancer. Herein, we report a case of primary adenocarcinoma arising from a rectal implantation cyst after LAR for rectal cancer. A 70-year-old woman was referred to our hospital for diagnosis and treatment of a growing cystic lesion. She had LAR performed for rectal cancer 29 years previously and had a rectal implantation cyst detected 13 years previously. On the first visit to our hospital, serum CEA and CA19-9 levels were elevated, and computed tomography (CT) scans revealed a cystic lesion near the anastomosis. CT-guided biopsy revealed no cancer tissue in the cystic lesion. After that, the cystic lesion naturally shrank, and serum CEA and CA19-9 levels became normal. Follow-up included 3 monthly serum CEA and CA19-9 testing and 6 monthly CT scans. Two years later, serum CEA and CA19-9 levels were elevated again. Colonoscopy revealed an ulcerative lesion at the anastomotic site, in which adenocarcinoma was confirmed. Abdominoperineal resection with sacral resection was performed, and postoperative histopathological examination revealed a primary adenocarcinoma with mucinous component at the implantation cyst. Since rectal implantation cysts can become malignant after extended periods, clinicians need to be aware of this disease.

Mucin phenotype and genetic alterations in non-V600E BRAF-mutated colorectal cancer.

Colorectal cancer (CRC) is a heterogeneous disease that develops through stepwise accumulation of genetic alterations and progresses via several distinct pathways. However, the tumorigenesis of CRCs with BRAF non-V600E mutations remains unclear. Here, we aimed to elucidate the tumorigenesis of CRCs with BRAF non-V600E mutations, focusing on differences in mucin phenotype and genetic alterations between CRCs with non-V600E and V600E mutations. We investigated 201 patients with CRC and performed panel testing of 415 genes to identify BRAF mutations. Patients were classified into five mucin phenotypes - large-intestinal, small-intestinal, gastric, mixed, and unclassified - using immunohistochemistry for CD10, MUC2, MUC5AC, and MUC6. BRAF mutations were identified in 24 of 201 patients' samples, of which 13 (6.5%) had a V600E mutation (V600E-mutant) and 11 (5.5%) had non-V600E mutations (non-V600E-mutant). MUC5AC expression was significantly associated with V600E mutations (P = 0.040), while CD10 expression was significantly associated with non-V600E mutations (P = 0.010). The small-intestinal mucin phenotype was significantly associated with non-V600E mutations (P = 0.031), while the mixed mucin phenotype was significantly associated with V600E mutations (P = 0.027). Regarding genetic alterations, focusing on the WNT signaling pathway, APC mutation was significantly associated with non-V600E mutations (P < 0.001), while RNF43 mutation was significantly associated with V600E mutations (P = 0.020). Considering the differences in mucin phenotype and genetic alterations, different modes of tumorigenesis are assumed for CRC with BRAF V600E mutation and non-V600E mutations. These findings are important in understanding the biology and treatment strategies for BRAF-mutant CRC.

Incarcerated Small Bowel Herniation in a Stoma Mimicking Sigmoid End Colostomy Prolapse.

Introduction: A stoma prolapse is easy to diagnose by visual examination, and it rarely incarcerates. Therefore, manual reduction is usually performed as soon as the diagnosis is made. In this report, we describe a case of stoma prolapse that could not be reduced manually and ruptured because an incarcerated parastomal hernia occurred in the stoma, mimicking stoma prolapse. Case Presentation: A 66-year-old woman underwent total hysterectomy, bilateral salpingo-oophorectomy, pelvic and para-aortic lymphadenectomy, omentectomy, resection of dissemination, and low anterior resection with formation of a sigmoid end colostomy for endometrial cancer with infiltration of the rectum. Fourteen months after the initial operation, she presented with stoma prolapse and multiple episodes of vomiting. The prolapsed stoma was 20 cm in length, appeared swollen and edematous, and was somewhat firm. Although it looked viable, some of the mucosa was darkish red, indicating congestion. Therefore, the diagnosis was sigmoid end colostomy prolapse with an ischemic component. An attempt at manual reduction resulted in rupture, so an emergency laparotomy was performed. Intraoperatively, we found that the ileum was incarcerated in the aperture created where the colostomy had been formed. When the incarcerated ileum was released, the stoma prolapse could be reduced easily. The end colostomy was refashioned in the left upper quadrant of the abdomen. Conclusion: An incarcerated parastomal hernia can mimic stoma prolapse. If the findings differ from those of typical stoma prolapse, imaging should be performed to confirm whether another clinical entity is involved in the stoma prolapse.

Axillary cutaneous metastasis of colon cancer with microsatellite instability-high and BRAF V600E mutation treated with curative-intent surgery: a case report.

BACKGROUND: Colorectal cancer (CRC) metastasizes to various organs, while cutaneous metastases are rare. Although there have been several previous reports of axillary cutaneous metastases with other metastases of CRC, there has never been a report of axillary cutaneous metastasis of CRC that could be treated with curative-intent surgery. CASE PRESENTATION: A 68-year-old female was diagnosed with an axillary cutaneous tumor and ascending colon cancer with invasion to the duodenum. Histopathological and immunohistochemical analysis revealed that the axillary cutaneous tumor showed adenocarcinoma and the same expression pattern for cytokeratin 7, cytokeratin 20, and CDX2 as the ascending colon cancer, and that proved to be KRAS-NRAS wild type, MSI-H, and with a BRAF V600E mutation. The patient underwent a two-stage resection with curative intent after receiving neoadjuvant chemotherapy which consisted of one cycle of modified FOLFOX6 followed by two cycles of FOLFOXIRI. During and after the two operations, the patient received a total of nine cycles of modified FOLFOX6 as adjuvant chemotherapy. Two years after the initial surgery, and 1 year and 8 months after the second surgery, the patient is alive without recurrence. CONCLUSIONS: To the best of our knowledge, this is the first report of axillary cutaneous metastasis of CRC with microsatellite instability-high and BRAF V600E mutation that could be treated with curative-intent surgery. It is important to recognize the presence of such cases for the accurate diagnosis and treatment of CRC with cutaneous metastasis.

Clinical significance of metastatic tumor deposit foci in rectal cancer in the lateral pelvic lymph node area.

BACKGROUND: Although previous studies have demonstrated that tumor deposits (TDs) are associated with worse prognosis in colon cancer, their clinical significance in rectal cancer has not been fully elucidated, especially in the lateral pelvic lymph node (LPLN) area. This study aimed to clarify the clinical significance of TDs, focusing on the number of metastatic foci, including lymph node metastases (LNMs) and TDs, in the LPLN area. METHODS: This retrospective study involved 226 consecutive patients with cStage II/III low rectal cancer who underwent LPLN dissection. Metastatic foci, including LNM and TD, in the LPLN area were defined as lateral pelvic metastases (LP-M) and were evaluated according to LP-M status: presence (absence vs. presence), histopathological classification (LNM vs. TD), and number (one to three vs. four or more). We evaluated the relapse-free survival of each model and compared them using the Akaike information criterion (AIC) and Harrell's concordance index (c-index). RESULTS: Forty-nine of 226 patients (22%) had LP-M, and 15 patients (7%) had TDs. The median number of LP-M per patient was one (range, 1-9). The best risk stratification power was observed for number (AIC, 758; c-index, 0.668) compared with presence (AIC, 759; c-index, 0.665) and histopathological classification (AIC, 761; c-index, 0.664). The number of LP-M was an independent prognostic factor for both relapse-free and overall survival, and was significantly associated with cumulative local recurrence. CONCLUSION: The number of metastatic foci, including LNMs and TDs, in the LPLN area is useful for risk stratification of patients with low rectal cancer.

[A Case of Appendiceal Carcinoma with BRAF V600E Mutation and Microsatellite Instability-High].

A 75-year-old woman presented to our hospital with abdominal pain and melena. Colonoscopy revealed an ulcer at the appendiceal orifice. Histopathological examination of biopsy specimens revealed adenocarcinoma. Computed tomography showed an appendiceal mass of 11.8×6.7 cm in size involving the cecum and terminal ileum without any distant metastatic findings. Ileocecal resection with regional lymph node dissection to the root of the ileocolonic artery was performed. Histopathological examination of the specimen revealed appendiceal adenocarcinoma. Molecular subtype of the tumor was BRAF V600E mutation and microsatellite instability-high(MSI-H). The pathological stage was pT4bpN1bcM0, pStage ⅢC. She received 8 courses of CapeOX as adjuvant chemotherapy and no recurrence was noted 12 months following the surgery. The establishment of standard treatment strategies including surgery, chemotherapy, and immunotherapy for carcinoma of the appendix with BRAF V600E mutation and/or MSI-H is needed.

[Laparoscopic Abdominoperineal Resection after Preoperative Chemoradiotherapy for Adenocarcinoma Associated with Anal Fistula].

A 72-year-old man had a chief complaint of anal pain and difficulty in defecation. He was diagnosed with adenocarcinoma by biopsy from a tumor of the anal canal. A computed tomography scan revealed neither regional lymph node metastasis nor distant metastasis. Hence, he was diagnosed with cT3N0M0, cStage Ⅱa anal canal cancer. Preoperative capecitabine- based chemoradiotherapy(CRT)(50.4 Gy in 28 fractions of 1.8 Gy each)was implemented. Digital rectal examination and imaging evaluation 8 weeks after preoperative CRT revealed that the tumor had shrunk. Fifteen weeks after preoperative CRT, laparoscopic abdominoperineal resection was performed. The pathological findings showed mucinous adenocarcinoma associated with anal fistula. At present, 12 months after the operation, no local recurrence and distant metastasis has been detected under follow-up evaluations.

The Combination of Modified Mitchell's Osteotomy and Shortening Oblique Osteotomy for Patients with Rheumatoid Arthritis: An Analysis of Changes in Plantar Pressure Distribution.

The present study aims to evaluate changes in plantar pressure distribution after joint-preserving surgery for rheumatoid forefoot deformity. A retrospective study was performed on 26 feet of 23 patients with rheumatoid arthritis (RA) who underwent the following surgical combination: modified Mitchell's osteotomy (mMO) of the first metatarsal and shortening oblique osteotomy of the lateral four metatarsals. Plantar pressure distribution and clinical background parameters were evaluated preoperatively and one year postoperatively. A comparison of preoperative and postoperative values indicated a significant improvement in the visual analog scale, Japanese Society for Surgery of the Foot scale, and radiographic parameters, such as the hallux valgus angle. A significant increase in peak pressure was observed at the first metatarsophalangeal joint (MTPJ) (0.045 vs. 0.082 kg/cm2; p < 0.05) and a significant decrease at the second and third MTPJs (0.081 vs. 0.048 kg/cm2; p < 0.05, 0.097 vs. 0.054 kg/cm2; p < 0.05). While overloading at the lateral metatarsal heads following mMO has been reported in previous studies, no increase in peak pressure at the lateral MTPJs was observed in our study. The results of our study show that this surgical combination can be an effective and beneficial surgical combination for RA patients with mild to moderate joint deformity.

[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.

Timing of Surgery to Treat Ulcerative Colitis: An Investigation Focused on Japanese Adults.

INTRODUCTION: There are no specific standards for the timing of surgery to treat ulcerative colitis, so reaching a decision on timing is often difficult. OBJECTIVE: The aim of this study was to evaluate the timing of surgery from the patients' perspective. METHODS: From among 203 patients who underwent restorative proctocolectomy with ileal pouch anal anastomosis to treat ulcerative colitis at our hospital from 1985 to 2013, we mailed a questionnaire to 101 of those who are currently attending periodic follow-up at our hospital. RESULTS: We analyzed 72 valid responses (71.2%). Overall, 65 patients (90.3%) responded that they were happy that they underwent surgery, 38 patients (52.8%) responded that the timing of surgery was appropriate, and 32 patients (44.4%) responded that they would have preferred to have had surgery earlier. The group of patients who would have preferred to have had surgery earlier included 23 patients (71.9%) who had undergone emergency surgery; the incidence of emergency surgery was significantly higher than in the group of 13 patients (34.2%) who had responded that the timing of surgery was appropriate (p = 0.002). Scores on the Medical Outcomes Study 36-Item Short-Form Health Survey (SF36), which reflect postoperative quality of life, were maintained at the same level as the Japanese standard values in our Japanese patients. CONCLUSION: The degree of satisfaction of patients who underwent surgery for ulcerative colitis was favorable, although it is important to consider surgery at an earlier stage in patients who may need emergency surgery.

Tolerance of anammox reactor packed with zeolite to partial supply of nitrite or ammonium using purified livestock wastewater.

Anammox reaction requires nitrite and ammonium in the ratio of 1.1-1.3. However, controlling a partial nitrification process prior to the anammox process to maintain this ratio in an influent to the anammox reactor is not easy. In this study, the effect of zeolite on anammox reaction was investigated to determine a method of ammonium preservation in case of partial supply of nitrite or ammonium. Up-flow column type anammox reactors, filled with either zeolite or non-woven fabric, were operated in two-week intervals with purified livestock wastewater containing either ammonium or nitrite. The zeolite reactor showed significantly higher nitrogen removal rates than the non-woven fabric reactor for both influents. When the influent contained ammonium, it was adsorbed onto zeolite, while anammox tolerated starvation for two weeks. In a subsequent reaction cycle, when the influent contained nitrite, anammox used the nitrite and the ammonium desorbed from zeolite. The highest nitrogen removal rates were 0.71 and 0.29 gN/L/day, observed in the zeolite reactor, with the ammonium and nitrite influents, respectively. The limiting factor for reactor performance was zeolite saturation level when the influent contained ammonium and anammox reaction rate when the influent contained nitrite. This study demonstrated that zeolite can buffer the unbalance of the nitrite to ammonium ratio in an anammox reaction, and showed the scopes for improvement under each influent.

Changes in radiographic findings and plantar pressure distribution following forefoot reconstructive surgery for patients with rheumatoid arthritis.

Objectives: To evaluate changes in radiographic findings and plantar pressure distribution after rheumatoid forefoot surgery.Methods: This study was performed on patients with rheumatoid arthritis (RA) who underwent Swanson implant arthroplasty for the 1st metatarsophalangeal (MTP) joint combined with shortening oblique osteotomy at the 2nd through 5th metatarsal necks (group Sw, 55 feet). The following two groups were used as controls: group NS, consisting of 75 feet in RA patients without scheduled forefoot surgery, and group HC, consisting of 24 feet in healthy female subjects. Plantar pressure distribution, and radiographic findings of hallux valgus angle, the angle between the metatarsal bones, talocalcaneal angle, calcaneal pitch angle and calcaneo-first metatarsal angle (CFMA) were measured pre- and one year postoperatively. Peak pressure was measured in nine sections.Results: Calcaneal pitch angle decreased and CFMA increased in group Sw. Peak pressure at the 1st interphalangeal joint (IP) and the 2nd and 3rd MTPs in group Sw decreased, while that at midfoot increased.Conclusion: While the clinical outcome in group Sw was favorable, postoperative longitudinal arch decreased. Postoperative peak pressure at the 2nd through 5th MTPs was comparable with that in group NS; however, it was significantly lower than that in group HC.

The clinical significance of distal spread differs according to the primary tumor location in rectal cancer.

PURPOSE: Treatment strategies of rectal cancer differ between tumors located above (RS/Ra) and below (Rb) the peritoneal reflection. Based on the extent of distal spread (DS), the Japanese Society for Cancer of Colon and Rectum proposed an optimal distal margin in RS/Ra and Rb tumors. In this study, we investigated the clinical significance of DS between RS/Ra and Rb tumors. METHODS: We analyzed 287 stage I-III rectal cancer patients who underwent curative intent resection without preoperative therapy. DS and other pathological factors were evaluated using whole-mount sections. To investigate the clinical significance of DS in RS/Ra and Rb tumors, clinicopathological variables, including DS, were analyzed for the survival outcome according to the tumor group. RESULTS: DS was detected in 20 out of 185 (11%) patients with RS/Ra tumors and 8 out of 102 (8%) patients with Rb tumors. DS was not significantly associated with the overall survival (OS) or relapse-free survival (RFS) in RS/Ra tumors, but was an independent prognostic factor for the OS and RFS in Rb tumors (P = 0.002 and 0.007, respectively). CONCLUSIONS: The clinical significance of DS differs between RS/Ra and Rb tumors. DS is associated with a worse survival in Rb tumors, but not in RS/Ra tumors.

SMAD4 alteration associates with invasive-front pathological markers and poor prognosis in colorectal cancer.

AIMS: SMAD4 acts as a tumour suppressor, and the loss of SMAD4 is associated with poor prognosis in colorectal cancer (CRC) patients. Although next-generation sequencing (NGS) enabled us to detect numerous genetic alterations in a single assay, the clinical significance of SMAD4 alteration detected with NGS has not been fully investigated. The aim of this study was to evaluate the clinicopathological characteristics and clinical significance of SMAD4 alteration detected with NGS in CRC. METHODS AND RESULTS: We retrospectively investigated 201 patients with stage I-IV CRC, by using a 415-gene panel. To analyse the relationship between SMAD4 alteration and other clinicopathological characteristics, we evaluated clinicopathological variables, including invasive-front pathological markers: tumour budding, poorly differentiated cluster, and Crohn-like lymphoid reaction. Fifty-six patients (28%) had SMAD4 alteration: 24 and 32 patients had SMAD4 mutation and deletion, respectively. SMAD4 alteration was significantly associated with T category (P = 0.027), N category (P = 0.037), M category (P = 0.028), and invasive-front pathological markers, such as poorly differentiated cluster grade 3 (P = 0.020) and absence of Crohn-like lymphoid reaction (P = 0.004). Immunohistochemistry revealed that SMAD4 alteration was significantly associated with loss of SMAD4 (P = 0.023). In 90 patients with stage I-III disease, SMAD4 alteration was significantly associated with poor prognosis for relapse-free and overall survival (P = 0.047; P = 0.022, respectively). Conversely, in 111 patients with stage IV disease, SMAD4 alteration was not significantly associated with overall survival. CONCLUSION: SMAD4 alteration is associated with invasive-front pathological markers and poor prognosis in stage I-III CRC patients.

Left colic artery aneurysm rupture after stent placement for abdominal aortic aneurysm associated with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is an autosomal dominant disease of the skin and soft tissue. Aneurysms associated with NF1 can occur, but a secondary aneurysm rupture is very rare, with very few cases reported in literature. CASE PRESENTATION: We describe the case of a 67-year-old female with NF1 who underwent endovascular aneurysm repair (EVAR) for an abdominal aortic aneurysm (AAA) rupture. She developed a type Ib endoleak requiring a redo-EVAR. Eighteen days after her primary operation, she was found to have two new left colic artery aneurysms. She required emergency surgery consisting of a left hemicolectomy and transverse colon colostomy. Pathology showed neurofibromatous changes to the peri-vasculature tissue, consistent with her underlying disease. CONCLUSIONS: Although rare, secondary aneurysms can occur following AAA repair. Patients with soft tissue connective tissue disorders, like NF1, may be at an increased risk for development of these secondary aneurysms. Endovascular repair appears to be a safe approach for NF1 patients with AAA, but endovascular management can be challenging in the setting of NF1. Surgeons should be ready to convert to open surgery if the patient displays persistent signs of bleeding or structural changes related to connective tissue disorders like NF1.

Feasibility of restorative proctocolectomy in patients with ulcerative colitis-associated lower rectal cancer: A retrospective study.

BACKGROUND/OBJECTIVE: Restorative proctocolectomy (RP) may improve quality of life in patients with ulcerative colitis (UC)-associated lower rectal cancer to a greater extent than total proctocolectomy. However, patients with UC-associated cancer often have flat mucosal lesions that make it extremely difficult to endoscopically delineate the tumor margins. Therefore, there is a potential risk of residual tumor and local recurrence after RP in patients with UC-associated lower rectal cancer. The aim of this study was to assess the feasibility of RP in patients with UC-associated cancer of the lower rectum. METHODS: We retrospectively identified nine patients who had undergone RP for UC-associated lower rectal cancer at the Niigata University Medical and Dental Hospital between January 2000 and December 2016. The incidence of flat mucosal cancer, distal margin status, and oncologic outcomes were evaluated in the nine patients. RESULTS: Eight (89%) of the nine patients had flat mucosal cancer in the lower rectum. The median length of the distal margin was 22 mm (range 0-55 mm). No patient developed local or distant recurrence during follow-up. One patient had a positive distal margin. This patient underwent annual pouchoscopy, but had no local recurrence and died of pancreatic cancer 81 months after RP. The remaining eight patients were alive at the final observation. Five-year and 10-year overall survival rates in the nine patients were 100% and 66.7%, respectively. CONCLUSION: Patients with UC-associated lower rectal cancer often have lesions of the flat mucosal type. However, RP is feasible and not necessarily contraindicated in such patients.

[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 Long-Term Survival after Resection for Metachronous Liver and Lung Metastases of Rectal Cancer Associated with Familial Adenomatous Polyposis].

A 37-year-old man was admitted to our hospital for the treatment of familial adenomatous polyposis and rectal carcinoma. He underwent total colectomy with ileoanal anastomosis(pT3N1M0, pStage Ⅲa)followed by adjuvant therapy with S-1. Three months after primary surgery, CT and MRIrevealed liver metastases(S5, S6). Laparoscopic partial hepatectomy was performed. Two years after primary surgery, new liver metastases(S2, S8)were found and we performed open partial hepatectomy and administered mFOLFOX6. Three years and 5 months after primary surgery, right lung metastases(S6, S9) were detected and the patient underwent a thoracoscopic-assisted right lung wedge resection. Repeated resection of metastases might have contributed to the long-survival in our case.

[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.