Correlation of circulating tumor DNA EGFR mutation levels with clinical outcomes in patients with advanced lung adenocarcinoma / 中华医学杂志(英文版)

BACKGROUND@#Circulating tumor DNA (ctDNA) is a promising biomarker for non-invasive epidermal growth factor receptor mutations (EGFRm) detection in lung cancer patients, but existing methods have limitations in sensitivity and availability. In this study, we used the ΔCt value (mutant cycle threshold [Ct] value-internal control Ct value) generated during the polymerase chain reaction (PCR) assay to convert super-amplification-refractory mutation system (superARMS) from a qualitative method to a semi-quantitative method named reformed-superARMS (R-superARMS), and evaluated its performance in detecting EGFRm in plasma ctDNA in patients with advanced lung adenocarcinoma.@*METHODS@#A total of 41 pairs of tissues and plasma samples were obtained from lung adenocarcinoma patients who had known EGFRm in tumor tissue and were previously untreated. EGFRm in ctDNA was identified by using superARMS. Through making use of ΔCt value generated during the detection process of superARMS, we indirectly transform this qualitative detection method into a semi-quantitative PCR detection method, named R-superARMS. Both qualitative and quantitative analyses of the data were performed. Kaplan-Meier analysis was performed to estimate the progression-free survival (PFS) and overall survival (OS). Fisher exact test was used for categorical variables.@*RESULTS@#The concordance rate of EGFRm in tumor tissues and matched plasma samples was 68.3% (28/41). At baseline, EGFRm-positive patients were divided into two groups according to the cut-off ΔCt value of EGFRm set at 8.11. A significant difference in the median OS (mOS) between the two groups was observed (EGFRm ΔCt ≤8.11 vs. >8.11: not reached vs. 11.0 months; log-rank P = 0.024). Patients were divided into mutation clearance (MC) group and mutation incomplete clearance (MIC) group according to whether the ΔCt value of EGFRm test turned negative after 1 month of treatment. We found that there was also a significant difference in mOS (not reached vs. 10.4 months; log-rank P = 0.021) between MC group and MIC group. Although there was no significant difference in PFS between the two groups, the two curves were separated and the PFS of MC group tended to be higher than the MIC group (not reached vs. 27.5 months; log-rank P = 0.088). Furthermore, EGFRm-positive patients were divided into two groups according to the cut-off of the changes in ΔCt value of EGFRm after 1 month of treatment, which was set at 4.89. A significant difference in the mOS between the two groups was observed (change value of ΔCt >4.89 vs. ≤4.89: not reached vs. 11.0 months; log-rank P = 0.014).@*CONCLUSIONS@#Detecting EGFRm in ctDNA using R-superARMS can identify patients who are more likely sensitive to targeted therapy, reflect the molecular load of patients, and predict the therapeutic efficacy and clinical outcomes of patients.

Genetic Variants in the ELOVL5 but not ELOVL2 Gene Associated with Polyunsaturated Fatty Acids in Han Chinese Breast Milk / 生物医学与环境科学（英文）

The present study was designed to examine the contributions of the fatty acid elongase (ELOVL) gene polymorphisms to the levels of polyunsaturated fatty acids (PUFAs) in breast milk. Two hundred and nine healthy Han Chinese mothers were included in the study. Carriers of minor alleles of SNPs (rs2397142 and rs9357760) in ELOVL5 were associated with higher levels of linoleic acid (LA), dihomo-γ-linolenic acid (DGLA), arachidonic acid (AA), docosatetraenoic acid (DTA), docosahexenoic acid (DHA), while in rs209512 of ELOVL5 the carriers of minor alleles had lower levels of DTA compared to major homozygote alleles (P ranged from 0.004-0.046), and genetically explained variability ranged from 3.2% for eicosapentaenoic acid (EPA) to 6.0% for LA. Our findings demonstrated that common variation in ELOVL5 gene encoding rate-limiting enzymes in the metabolism of PUFAs contribute to the PUFAs in breast milk.