Evaluation of bacterial contamination and medium-term oncological outcomes of intracorporeal anastomosis for colon cancer:A propensity score matching analysis

BACKGROUND Although intracorporeal anastomosis(IA)for colon cancer requires longer operative time than extracorporeal anastomosis(EA),its short-term postoperative results,such as early recovery of bowel movement,have been reported to be equal or better.As IA requires opening the intestinal tract in the abdominal cavity under pneumoperitoneum,there are concerns about intraperitoneal bacterial infection and recurrence of peritoneal dissemination due to the spread of bacteria and tumor cells.However,intraperitoneal bacterial contamination and medium-term oncological outcomes have not been clarified.abdominal cavity in IA.METHODS Of 127 patients who underwent laparoscopic colon resection for colon cancer from April 2015 to December 2020,75 underwent EA(EA group),and 52 underwent IA(IA group).After propensity score matching,the primary endpoint was 3-year disease-free survival rates,and secondary endpoints were 3-year overall survival rates,type of recurrence,surgical site infection(SSI)incidence,number of days on antibiotics,and postoperative biological responses.RESULTS Three-year disease-free survival rates did not significantly differ between the IA and EA groups(87.2%and 82.7%,respectively,P=0.4473).The 3-year overall survival rates also did not significantly differ between the IA and EA groups(94.7%and 94.7%,respectively;P=0.9891).There was no difference in the type of recurrence between the two groups.In addition,there were no significant differences in SSI incidence or the number of days on antibiotics;however,postoperative biological responses,such as the white blood cell count(10200 vs 8650/mm^(3),P=0.0068),C-reactive protein(6.8 vs 4.5 mg/dL,P=0.0011),and body temperature(37.7 vs 37.5℃,P=0.0079),were significantly higher in the IA group.CONCLUSION IA is an anastomotic technique that should be widely performed because its risk of intraperitoneal bacterial contamination and medium-term oncological outcomes are comparable to those of EA.

Colon cancer arising from colonic diverticulum:A case report

BACKGROUND Colonic diverticulosis is a common disease, and the coexistence of colonic diverticulosis and colorectal cancer is often seen clinically. It is very rare that colon cancer arises from the mucosa of a colonic diverticulum. When colon cancer arises in a diverticulum and then tends to develop outside the wall, without developing within the lumen, the differential diagnosis from complicating lesions due to colonic diverticulitis is difficult. CASE SUMMARY A 76-year-old man was admitted to a nearby clinic with a chief complaint of discomfort and urinary frequency. Since a vesicosigmoidal fistula was seen on abdominal computed tomography, he was referred to our hospital. Laparoscopic sigmoidectomy was performed because the various diagnostic findings were diagnosed as a vesicosigmoidal fistula with diverticulitis of the sigmoid colon. However, on histopathological examination, it was diagnosed as a vesicosigmoidal fistula due to colon cancer arising in the diverticulum. Laparoscopic partial resection of the bladder was performed because local recurrence was observed in the bladder wall one and a half years after surgery. It is currently one year after reoperation, but there has been no recurrence or metastasis. CONCLUSION Colon cancer arising in a diverticulum of the colon should be considered when diverticulitis with complications is observed.

Neoadjuvant chemoradiotherapy for locally advanced gastric cancer with bulky lymph node metastasis:Five case reports

BACKGROUND Neoadjuvant chemoradiotherapy(NACRT)has not been accepted as a general therapy for gastric cancer because of its localized effect and toxicity for radiosensitive organs.However,if radiation therapy could compensate for the limited or inadequate treatment choices available for elderly patients and/or those at high risk,the available therapeutic options for advanced gastric cancer might increase.From this perspective,we present our experiences of five patients with advanced gastric cancer in whom we used NACRT therapy with interesting results.CASE SUMMARY We admitted five patients with clinical Stage III gastric cancer and bulky lymph node metastasis or adjacent organ invasion at the time of diagnosis.A total of 50 Gy of preoperative intensity modulated radiation therapy was delivered to the patients in doses of 2.0 Gy/d,together with a regimen of concomitant chemotherapy comprising two courses of oral tegafur/gimeracil/oteracil(S-1;65 mg/m2 per day)for three consecutive weeks followed by two weeks of rest,starting at the same time as radiotherapy.All patients underwent no residual tumor resection and a pathological complete response of the primary tumors was achieved in two patients.The incidence of hematological toxicity was low,although the digestive toxicities of anorexia and diarrhea developed in three of the five patients,necessitating termination of radiation therapy at 30 Gy and S-1 at three weeks.However,even 30 Gy of irradiation and half the dose of S-1 resulted in sufficient downstaging,indicating that even a reduced amount of NACRT could confer considerable effects.CONCLUSION Slightly reduced NACRT might be useful and safe for patients with locally advanced gastric cancer.

Classification of rectal cancer according to recurrence types-comparison of Japanese guidelines and Western guidelines

BACKGROUND Rectal cancer is characterized by more local recurrence(LR)and lung metastasis than colon cancer.However,the diagnosis of rectal cancer is not standardized as there is no global consensus on its definition and classification.The classification of rectal cancer differs between Japanese and Western guidelines.AIM To clarify the characteristics of rectal cancer by comparing the tumor location and characteristics of rectal cancer with those of colon cancer according to each set of guidelines.METHODS A total of 958 patients with Stage II and III colorectal cancer were included in the analysis:607 with colon cancer and 351 with rectal cancer.Localization of rectal cancers was assessed by enema examination and rigid endoscopy.According to Japan guidelines,rectal cancer is classified as Rb(below the peritoneal inversion),Ra(between the inferior margin of second sacral vertebrae and Rb)or RS(between Ra and sacral promontory).RESULTS There were no significant differences between RS rectal cancer and colon cancer in the rates of liver and lung metastasis or LR.Lung metastasis and LR were significantly more common among Rb rectal cancer(in Japan)than in colon cancer(P=0.0043 and P=0.0002,respectively).Lung metastases and LR occurred at significantly higher rates in rectal cancer measuring≤12 cm and≤10 cm than in colon cancers(P=0.0117,P=0.0467,P=0.0036,P=0.0010).Finally,the rates of liver metastasis,lung metastasis,and LR in rectal cancers measuring 11 cm to 15 cm were 6.9%,2.8%,and 5.7%,respectively.These were equivalent to the rates in colon cancer.CONCLUSION High rectal cancer may be treated with the same treatment strategies as colon cancer.There was no difference in the classification of colorectal cancer between Japan and Western countries.