Objective To analyze the clinical diagnosis and treatment of recurrent cancer in gastric remnant.Methods Clinical data of 48 patients who underwent surgical re-operation because of recurrent carcinoma within gastric remnant after radical resection of gastric cancer were analyzed retrospectively.Results All 48 cases were recurrent cancer in gastric stump.The time of recurrence was 6-36 months after first radical resection.After reoperation,the mean survival time of 28 patients(58.3%)who underwent radical resection was 40 months;the mean survival time of 20 patients(41.7%)who received palliative treatment was 14.8 months(P

Objective To study the causes of local recurrence,and diagnosis and treatment outcome of recurrent colorectal cancer.Methods The clinical data of 60 patients with recurrent colorectal cancer treated during 10 years in our hospital were analyzed retrospectively.Results Among the 60 cases,40 cases(66.7 %) had recurrence within 2 years after operation.Recurrence in anastomotic stoma,perineum,abdominal incision occurred and in the abdominal cavity and pelvic cavity in 15,10,7 and 20 cases respectively,and liver metastases were found in 8 cases.All patients underwent reoperation including curative surgery for 38 patients and palliative operation for 22 patients.After radical reoperation the 1-,3-,and 5-year survival rate was 93.6 %,48.8 %,and 36.3 %,respectively,and after palliative reoperation was 54.5 %,0 %,and 0 %,respectively.Conclusions Emphasizing the application of no-tumor touch technique,resection of adequate amount of bowel,performing complete lymphadenectomy and removal of micrometastatic lesions are the major measures to prevent recurrence of rectal cancer after operation.Integrative therapy regimens,of which surgical treatment is the major component,should be considered according to the location of recurrence and the clinical staging of the recurrent cases.

Objective: To identify risk factors for positive surgical margin after laparoscopic radical prostatectomy. Method: The study retrospectively analyzed the records of 177 patients with prostate cancer who eventually underwent laparoscopic radical prostatecto-my from January 2016 to December 2017 in Peking University First Hospital. Age, prostate volume, prostate-specific antigen (PSA) be-fore needle biopsy, number of positive cores, positive percentage of needle biopsy and biopsy, and postoperative Gleason scoreand pathological stage were analyzed. Results: The overall positive surgical margin rate was 32.2% (57/177). Age, prostate volume, PSA be-fore needle biopsy, positive percentage of biopsy, and postoperative Gleason score were not significantly different (P>0.05). The study demonstrated significant differences between the number of positive cores, positive percentage of needle biopsy, and pathological stage (P<0.05). Multiple logistic regression revealed that the pathological stage was an independent factor affecting the positive surgi-cal margin rate (odds ratio, 1.616; 95% confidence interval, 1.062-2.459). Conclusions: The number of positive cores, positive percent-age of needle biopsy, and pathological stage significantly correlated with a positive surgical margin. The postoperative pathological T stage is an independent factor affecting positive surgical margins.

Postzygotic mutations are acquired in normal tissues throughout an individual's lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using optimized ultra-deep exome sequencing of the time-series samples from the same volunteer as well as the samples from different individuals.In blood,sperm,and muscle cells,we resolved three common types of mutational signatures.Signatures A and B represent clock-like mutational processes,and the polymorphisms of epigenetic regulation genes influence the pro-portion of signature B in mutation profiles.Notably,signature C,characterized by C＞T transitions at GpCpN sites,tends to be a feature of diverse normal tissues.Mutations of this type are likely to occur early during embryonic development,supported by their relatively high allelic frequencies,presence in multiple tissues,and decrease in occurrence with age.Almost none of the public datasets for tumors feature this signature,except for 19.6％of samples of clear cell renal cell carcinoma with increased activation of the hypoxia-inducible factor 1(HIF-1)signaling pathway.Moreover,the accumulation of signature C in the mutation profile was accelerated in a human embryonic stem cell line with drug-induced activation of HIF-1α.Thus,embryonic hypoxia may explain this novel signature across multiple normal tissues.Our study suggests that hypoxic condition in an early stage of embryonic development is a crucial factor inducing C＞T transitions at GpCpN sites;and indi-viduals'genetic background may also influence their postzygotic mutation profiles.