EGFR mutation status in tumour-derived DNA from pleural effusion fluid is a practical basis for predicting the response to gefitinib

Detection and comparison of epidermal growth factor receptor mutations in cells and fluid of malignant pleural effusion in non-small cell lung cancer

Cells or cell-free fluid of malignant pleural effusion could be important clinical specimen for epidermal growth factor receptor (EGFR) mutation screening in advanced non-small cell lung cancer (NSCLC) patients. However, their usefulness in mutation detection has not been well compared. In this study we recruited 26 East Asian NSCLC patients with malignant pleural effusion, determined the mutation status of EGFR in both cells and matched cell-free fluid with the use of sequencing and mutant-enriched PCR. After comparing the mutation spectrums, we found both the cells and cell-free pleural fluid may be feasible clinical specimen for EGFR mutation detection in unresectable NSCLC given sensitive genotyping assays employed. Direct sequencing could miss a significant portion of mutations in these heterogeneous specimens. More sensitive methods, such as mutant-enriched PCR and gene scan, could provide more reliable mutational information.

Chromosomal aberrations of malignant pleural effusions of lung adenocarcinoma: different cytogenetic changes are correlated with genders and smoking habits

Chromosomal aberrations of malignant cells from pleural effusions of 31 cases of lung adenocarcinoma were analyzed. Pooled CGH results showed frequent amplifications on chromosome arms 1p (22.6%), 1q (35.5%), 2q (25.8%), 3q (38.7%), 4q (41.9%), 5p (41.9%), 5q (51.6%), 6p (19.4%), 6q (25.8%), 7p (41.9%), 7q (35.5%), 8q (32.3%), 12q (38.7%), 13q (22.6%), 14q (35.5%), 17q (19.4%), Xp (22.6%), and Xq (38.7%). Frequent deletions were found on 1p (19.4%), 3p (16.1%), 4q (16.1%), 8p (25.8%), 9p (22.6%), 9q (29.0%), 10q (22.6%), 13q (22.6%), 16p (19.4%), 16q (22.6%), 17p (29.0%), 18q (16.1%), 19p (41.9%), 19q (32.3%), 20p (19.4%) and 22q (29%). These genomic changes were generally found consistent with previous reports of CGH analysis of primary tumors of lung adenocarcinoma. Loss of 19q and 22q were more frequently found in our studies (32.3% and 29.0%, respectively) than studies of primary tumors (less than 7% for both genetic changes). Gain of 11p, although not a frequent finding, was relatively more common in this (16%) than other studies (range, 2.9-11.8%). Interestingly, occurrences of 3p loss and 11p gain were higher in smokers than non-smokers, and deletion of 3p and increased copy number of 11p and Xp appeared more often in male than female patients. Among 17 male patients, gain of chromosomal 11p was a frequent aberration in tumors of smokers, while gain of Xp was more easily found in tumors of non-smokers. One candidate gene located within 11p15, lactate dehydrogenase C (LDHC), was selected for further study. Three cases with 11p gain had amplified FISH signals of LDHC. Also tumors from smokers or male had significantly higher transcript level of LDHC than non-smokers or female, respectively. The results demonstrate that different cytogenetic changes of malignant pleural effusions from lung adenocarcinoma are correlated with genders and smoking habits. The role of LDHC in the carcinogenesis of smoking-related lung adenocarcinoma, especially in male patients with pleural effusions, deserves further investigations.