Clinicopathological characteristics and prognosis of patients with small bowel tumors: A single center analysis of 220 cases / 中华胃肠外科杂志

Objective: To analyze the clinicopathological characteristics and prognosis of patients with small bowel tumors. Methods: This was a retrospective, observational study. We collected clinicopathological data of patients with primary jejunal or ileal tumors who had undergone small bowel resection in the Department of Gastrointestinal Surgery, West China Hospital, Sichuan University between January 2012 and September 2017. The inclusion criteria included: (1) older than 18 years; (2) had undergone small bowel resection; (3) primary location at jejunum or ileum; (4) postoperative pathological examination confirmed malignancy or malignant potential; and (5) complete clinicopathological and follow-up data. Patients with a history of previous or other concomitant malignancies and those who had undergone exploratory laparotomy with biopsy but no resection were excluded. The clinicopathological characteristics and prognoses of included patients were analyzed. Results: The study cohort comprised 220 patients with small bowel tumors, 136 of which were classified as gastrointestinal stromal tumors (GISTs), 47 as adenocarcinomas, and 35 as lymphomas. The median follow-up for all patient was 81.0 months (75.9-86.1). GISTs frequently manifested as gastrointestinal bleeding (61.0%, 83/136) and abdominal pain (38.2%, 52/136). In the patients with GISTs, the rates of lymph node and distant metastasis were 0.7% (1/136) and 11.8% (16/136), respectively. The median follow-up time was 81.0 (75.9-86.1) months. The 3-year overall survival (OS) rate was 96.3%. Multivariate Cox regression-analysis results showed that distant metastasis was the only factor associated with OS of patients with GISTs (HR=23.639, 95% CI: 4.564-122.430, P<0.001). The main clinical manifestations of small bowel adenocarcinoma were abdominal pain (85.1%, 40/47), constipation/diarrhea (61.7%, 29/47), and weight loss (61.7%, 29/47). Rates of lymph node and distant metastasis in patients with small bowel adenocarcinoma were 53.2% (25/47) and 23.4% (11/47), respectively. The 3-year OS rate of patients with small bowel adenocarcinoma was 44.7%. Multivariate Cox regression-analysis results showed that distant metastasis (HR=4.018, 95%CI: 2.108-10.331, P<0.001) and adjuvant chemotherapy (HR=0.291, 95% CI: 0.140-0.609, P=0.001) were independently associated with OS of patients with small bowel adenocarcinoma. Small bowel lymphoma frequently manifested as abdominal pain (68.6%, 24/35) and constipation/diarrhea (31.4%, 11/35); 77.1% (27/35) of small bowel lymphomas were of B-cell origin. The 3-year OS rate of patients with small bowel lymphomas was 60.0%. T/NK cell lymphomas (HR= 6.598, 95% CI: 2.172-20.041, P<0.001) and adjuvant chemotherapy (HR=0.119, 95% CI: 0.015-0.925, P=0.042) were independently associated with OS of patients with small bowel lymphoma. Small bowel GISTs have a better prognosis than small intestinal adenocarcinomas (P<0.001) or lymphomas (P<0.001), and small bowel lymphomas have a better prognosis than small bowel adenocarcinomas (P=0.035). Conclusions: The clinical manifestations of small intestinal tumor are non-specific. Small bowel GISTs are relatively indolent and have a good prognosis, whereas adenocarcinomas and lymphomas (especially T/NK-cell lymphomas) are highly malignant and have a poor prognosis. Adjuvant chemotherapy would likely improve the prognosis of patients with small bowel adenocarcinomas or lymphomas.

Clinical significance of No.11p posterior lymph nodes dissection in gastric cancer surgery / 中华胃肠外科杂志

Objective: To analyze the association of No.11p posterior lymph node metastasis with clinicopathological features and its prognostic significance in gastric cancer. Methods: A single-center retrospective cohort study was conducted. Clinicopathological data of patients with primary gastric cancers undergoing No.11p posterior lymph node dissection from January 2016 to December 2020 were retrieved from the Database of Gastric Cancer, West China Hospital, Sichuan University. Case inclusion criteria: (1) gastric cancer proved by pathology; (2) radical resection with intraoperative No.11p posterior lymph node dissection; (3) operations performed by the same surgical team; (4) no previous history of other malignant tumors and no concurrent malignant tumors. Those with stump gastric cancer, history of gastrectomy, neoadjuvant chemotherapy, incomplete clinicopathological data and lost to follow-up were excluded. During the operation, the upper edge of the pancreas was retracted forward to expose the area between the upper edge of the pancreas and the splenic vessels. The proximal segment of the splenic artery was skeletonized to remove lymphatic tissue anterior and superior to the splenic artery for No.11p lymph node dissection. For patients with lymphadenopathy in the area between the splenic artery and the splenic vein, dissection was performed. The enlarged lymph nodes were labeled with titanium clips and named as No.11p posterior lymph node. Pathological examination was performed separately after the specimen was isolated. Statistical analysis was performed using R software. Results: A total of 127 gastric cancer patients, who underwent No.11p posterior lymph nodes dissection were included in this study, of which 120 patients without No.11p posterior lymph nodes metastasis (No.11p posterior lymph nodes negative) and 7 patients with No.11p posterior lymph nodes metastasis (No.11p posterior lymph nodes positive). A total of 8 metastatic No.11p posterior lymph nodes were detected in 7 patients, metastasis rate and with a ratio of 5.5% (7/127) and 6.8% (8/127), respectively. In the subgroup analysis of T3-4 stage patients, the metastasis rate and ratio of No.11p posterior lymph nodes were 9.0% (7/78) and 10.7% (8/75), respectively. Compared to negative cases, patients with No.11p posterior lymph nodes metastasis had larger tumor (P=0.002), higher proportion of Borrmann type Ⅲ and Ⅳ tumors (P=0.005), more metastatic lymph nodes (P<0.001), more advanced T stage (P=0.043), N stage (P=0.004) and TNM stage (P=0.015). In survival analysis, patients with No.11p posterior lymph node metastasis had a significantly worse prognosis than those without metastasis after adjusting for TNM stage (hazard ratio=3.009, 95% confidence interval: 1.824-4.964, P<0.001). Conclusions: The No.11p posterior lymph node metastasis in gastric cancer is associated with worse prognosis. For patients of T3-4 stage gastric cancer, No.11p posterior lymph node dissection should be emphasized during radical operation.

Mapping the epigenetic modifications of DNA and RNA

Over 17 and 160 types of chemical modifications have been identified in DNA and RNA, respectively. The interest in understanding the various biological functions of DNA and RNA modifications has lead to the cutting-edged fields of epigenomics and epitranscriptomics. Developing chemical and biological tools to detect specific modifications in the genome or transcriptome has greatly facilitated their study. Here, we review the recent technological advances in this rapidly evolving field. We focus on high-throughput detection methods and biological findings for these modifications, and discuss questions to be addressed as well. We also summarize third-generation sequencing methods, which enable long-read and single-molecule sequencing of DNA and RNA modification.