Detection of Rare Mutations in EGFR-ARMS-PCR-Negative Lung Adenocarcinoma by Sanger Sequencing

PURPOSE: This study aimed to identify potential epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer that went undetected by amplification refractory mutation system-Scorpion real-time PCR (ARMS-PCR). MATERIALS AND METHODS: A total of 200 specimens were obtained from the First Affiliated Hospital of Guangzhou Medical University from August 2014 to August 2015. In total, 100 ARMS-negative and 100 ARMS-positive specimens were evaluated for EGFR gene mutations by Sanger sequencing. The methodology and sensitivity of each method and the outcomes of EGFR-tyrosine kinase inhibitor (TKI) therapy were analyzed. RESULTS: Among the 100 ARMS-PCR-positive samples, 90 were positive by Sanger sequencing, while 10 cases were considered negative, because the mutation abundance was less than 10%. Among the 100 negative cases, three were positive for a rare EGFR mutation by Sanger sequencing. In the curative effect analysis of EGFR-TKIs, the progression-free survival (PFS) analysis based on ARMS and Sanger sequencing results showed no difference. However, the PFS of patients with a high abundance of EGFR mutation was 12.4 months [95% confidence interval (CI), 11.6−12.4 months], which was significantly higher than that of patients with a low abundance of mutations detected by Sanger sequencing (95% CI, 10.7−11.3 months) (p < 0.001). CONCLUSION: The ARMS method demonstrated higher sensitivity than Sanger sequencing, but was prone to missing mutations due to primer design. Sanger sequencing was able to detect rare EGFR mutations and deemed applicable for confirming EGFR status. A clinical trial evaluating the efficacy of EGFR-TKIs in patients with rare EGFR mutations is needed.

Therapeutic effect of endoscopic retrograde biliary drainage and nasal biliary drainage for hilar cholangiocarcinoma / 中华消化内镜杂志

Objective To evaluate the clinical effect of endoscopic retrograde biliary drainage (ERBD) and endoscopic naso-biliary drainage (ENBD) on hilar cholangiocarcinoma (HACC).Methods The clinical data of 87 patients with HACC,who underwent ERBD and ENBD form January 2010 to January 2016,were retrospectively analyzed.The incidence of postoperative severe cholangitis,biliary obstruction again within 4 weeks,reduction of total bilirubin and survival time were studied.Results There were significant differences between ERBD group and ENBD group on the incidence of severe cholangitis[29.2％ (14/48) VS 10.3％ (4/39),x2 =4.689,P=0.030] and bile duct obstruction in 4 weeks after operation [47.9％ (23/48) VS 23.1％ (9/39),x2=5.710,P =0.017].The total bilirubin within 2 weeks and 4 weeks postoperatively was significantly reduced compared with that before operation (P＜0.05).There was no statistical difference in descend range of total bilirubin between the two groups.There was significant difference between ERBD group and ENBD group in the median survival time [14 weeks (range,0-60 weeks) VS 34 weeks (range,2-96 weeks),x2 =10.101,P=0.010].Conclusion Compared to ERBD,ENBD has certain advantages on palliative care for HACC.