OBJECTIVETo investigate gene mutations of epidermal growth factor receptor (EGFR) and K-ras in Chinese patients with non-small cell lung cancer (NSCLC) and its clinicopathological significance, and to analyze the correlation between these mutations and tumor response to erlotinib treatment.

METHODSMutations of exons 18, 19, 20 and 21 of the EGFR and codons 12, 13 of the K-ras in 301 cases of NSCLC were detected by PCR-amplification and gene sequencing. The relationship between the mutations and clinicopathological characteristics of the 301 patients was analyzed.

RESULTSEGFR mutations were present in 32.9% (99/301) of the samples: 3 mutation in exon 18, 59 in exon 19, 2 in exon 20, and 35 in exon 21. Mutations of K-ras were present in 4.7% (14/301) of the samples: 13 in codon 12 and 1 in codon 13. EGFR mutations were never found in tumors with K-ras mutations, suggesting a mutually exclusive relationship. EGFR mutations were more common in adenocarcinomas, non-smokers and females. Seven out of 10 erlotinib-treated patients with disease control carried EGFR mutation.

CONCLUSIONThe frequency of EGFR mutation in Chinese NSCLC patients is higher than that in Westerners, but the frequency of K-ras mutation is quite opposite. Combined detection of EGFR gene and K-ras gene mutation may help clinicians to choose patients who may gain benefit from EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment, and to predict their response to erlotinib treatment and prognosis.

Adenocarcinoma ; drug therapy ; genetics ; pathology ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; pathology ; Carcinoma, Squamous Cell ; drug therapy ; genetics ; pathology ; Codon ; Erlotinib Hydrochloride ; Exons ; Female ; Genes, erbB-1 ; Genes, ras ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; pathology ; Male ; Middle Aged ; Mutation ; Protein Kinase Inhibitors ; therapeutic use ; Proto-Oncogene Proteins ; genetics ; Proto-Oncogene Proteins p21(ras) ; Quinazolines ; therapeutic use ; Receptor, Epidermal Growth Factor ; genetics ; Sex Factors ; Smoking ; Young Adult ; ras Proteins ; genetics

Objective: To explore the efficacy and feasibility of transanal hand-sewn reinforcement of low stapled anastomosis in preventing anastomotic leak after transanal total mesorectal excision (taTME). Methods: A descriptive cohort study was conducted. Clinical data of 51 patients with rectal cancer who underwent taTME with transanal hand-sewn reinforcement of low stapled anastomosis at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2020 were retrospectively collected. Inclusion criteria: (1) age >18 years old; (2) rectal cancer confirmed by preoperative pathology; (3) distance from tumor to anal verge ≤ 8 cm according to pelvic MR; (4) the lesion was evaluated to be resectable before operation; (5) with or without neoadjuvant chemotherapy and radiotherapy; (6) taTME, end-to-end stapled anastomosis, and reinforcement in the anastomosis with absorbable thread intermittently were performed, and the distance between anastomosis and anal verge was ≤ 5 cm. Exclusion criteria: (1) previous history of colorectal cancer surgery; (2) emergency surgery due to intestinal obstruction, bleeding or perforation; (3) patients with local recurrence or distant metastasis; (4) the period of postoperative follow-up less than 3 months. The procedure of transanal hand-sewn reinforcement was as follows: firstly, no sign of bleeding was confirmed after checking the anastomosis. Then, the anastomosis was reinforced by suturing the muscle layer of rectum intermittently in a figure-of-eight manner using 3-0 single Vicryl. The entry site of the next suture was close next to the exit site of the last one. Any weak point of the anastomosis could also be reinforced according to the specimen from the circular stapler. The primary outcome were the incidence of anastomotic leak, methods of the secondary operation, anastomotic infection, anastomotic stricture, and conditions of Intraoperative and postoperative. Results: All the 51 enrolled patients completed surgery successfully without any conversion to open surgery. The median operative time was 169 (109-337) minutes, and the median intraoperative blood loss was 50 (10-600) ml. The median postoperative hospital stay was 8 (5-16) days. The mssorectum was complete and distal resection margin was negative in all patients. Postive circumferential resection margin was observed in 1 patients (2.0%). Twelve (23.5%) patients underwent prophylactic ileostomy. One patient developed anastomosis stricture which was cured by digital dilatation of the anastomosis. ISREC grade C anastomotic leak was observed in 3 (5.9%) male patients, of whom 2 cases did not received prophylactic ileostomy during the operation, and were cured by a second operation with the ileostomy and anastomotic repair. The other one healed by transanal repair of the anastomosis and anti-infection therapy. One (2.0%) patient suffered from perianal infection and healed by sitz bath and anti-infection therapy. No death was reported within 30 days after operation. Conclusion: Transanal hand-sewn reinforcement in low rectal stapled anastomosis in preventing anastomotic leak after taTME is safe and feasible.
Adolescent ; Anal Canal/surgery* ; Anastomosis, Surgical ; Anastomotic Leak/prevention & control* ; Cohort Studies ; Humans ; Laparoscopy ; Male ; Postoperative Complications/prevention & control* ; Rectal Neoplasms/surgery* ; Rectum/surgery* ; Retrospective Studies ; Treatment Outcome