ABSTRACT
PURPOSE: Most common EGFR mutations in NSCLC include del19 and exon 21 L858R. Approximately 10% of patients have uncommon EGFR mutations (indels, missense mutations involving G719, L861 and S768 codons, and exon 20 insertions) that do not respond to TKIs. METHODS: Of 490 EGFR mutated NSCLC samples, 60 cases harboring uncommon/compound EGFR mutations were reviewed retrospectively, and 44 were included for survival analysis. RESULTS: Sixty (12.2%) patients with a median age of 63 years (25-84 years) had uncommon/compound EGFR mutations. Majority had no history of smoking (52; 86.7%). Most common major uncommon mutations (G719X in exon 18, L861Q in exon 21 and S768I in exon 20) were identified in 19 (31.7%) patients. 17 (28.3%) cases demonstrated exon 20 insertions. De novo T790M was observed in 7 (11.7%) cases and 9 cases exhibited compound/dual mutations. Among the 12 patients who received first-line EGFR TKI, 7 received afatinib. Median progression-free survival of patients following first-line afatinib was 8.13 months, irrespective of mutation type exhibited. Overall response rate to first-line afatinib therapy was 57.1%. CONCLUSION: The current study highlighted that rare/dual EGFR mutations are heterogeneous with distinct clinical features in a large Indian cohort of EGFR mutated patients with NSCLC.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Middle Aged , Afatinib , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Mutation , Protein Kinase Inhibitors/therapeutic use , ErbB Receptors/genetics , Retrospective Studies , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/geneticsABSTRACT
CONTEXT: Lung cancer has been the most common cancer in the world for several decades. Pemetrexed is recommended as an option for the maintenance treatment in metastatic adenocarcinoma lung, if disease has not progressed immediately following platinum-based chemotherapy. AIMS: To study efficacy and toxicity profile of pemetrexed as a maintenance chemotherapeutic agent in patients with stage IV adenocarcinoma lung, not progressing after first line chemotherapy. Settings and Design: This was an observational, prospective. We enrolled patients with stage IV adenocarcinoma lung who has not progressed on first line chemotherapy, from September 2013 to August 2014 at a tertiary care cancer institute in North India. MATERIALS AND METHODS: In all, 108 patients with stage IV adenocarcinoma lung were started on induction pemetrexed/platinum chemotherapy. 60 patients with no disease progression & ECOG PS 0-2 were started on Pemetrexed maintenance. Progression free survival (PFS) and toxicity profile were recorded. RESULTS: The mean number of maintenance cycles was 8.3 (range 2-28). 13 (21.6%) patients took >10 maintenance cycles. Pemetrexed maintenance therapy resulted in progression free survival (PFS) of 5.4 months. PFS on pemetrexed was consistent for all patient subgroups, including induction response: complete/partial responders (n-31) and stable disease (n-29). 14 patients had grade III/IV adverse events with anemia being the most common in 3/60 patients (5%). 3 patients (5%) developed renal dysfunction out of which 1 was grade III. CONCLUSIONS: Pemetrexed continuation maintenance chemotherapy is active and well tolerated. Pemetrexed maintenance should be considered in patients with advanced adenocarcinoma lung patients who have not progressed on completion of induction chemotherapy.
