EGFR mutation prevalence, real-world treatment patterns, and outcomes among patients with resected, early-stage, non-small cell lung cancer in Canada.

OBJECTIVES: The ADAURA trial demonstrated the benefit of adjuvant osimertinib among patients with resected, early-stage, epidermal growth factor receptor-mutated (EGFRm) non-small cell lung cancer (NSCLC). To understand the potential population impact, it is critical to deduce the prevalence, management, and outcomes of this patient population in the real-world setting before use of adjuvant osimertinib. MATERIALS AND METHODS: Using PALEOS (Pan-cAnadian Lung cancEr Observational Study) data (2012-2019), a retrospective, multi-center, observational cohort study was conducted among patients with early-stage (IB-IIIA) resected NSCLC who had not received neoadjuvant therapy. Study outcomes included EGFRm prevalence, treatment patterns, recurrence outcomes, and overall and disease-free survival (OS/DFS). RESULTS: Among patients undergoing reflexive EGFRm testing by a pathologist at time of diagnosis irrespective of disease stage (N = 535), 23 % were EGFRm-positive; 15.9 % had common mutations and 5.6 % had uncommon mutations. Within the EGFRm-positive cohort (N = 156), mean age at diagnosis was 68 years, 65 % of patients were female, and 35 % were of Asian descent. At diagnosis, 48 %, 31 %, and 21 % had stage IB, II, or IIIA disease, respectively; 46 % received adjuvant therapy after resection. Half of patients experienced disease recurrence, typically involving distant sites; central nervous system metastasis varied from 12 % to 15.0 % across disease stages. EGFR tyrosine kinase inhibitors were the most commonly received therapy after first metastatic recurrence. Median OS (DFS) was not reached, 71.2 (22.8) months, and 50.1 (18.0) months among stage IB, II, and IIIA patients. Patients with uncommon EGFRm had a lower probability of survival than those with common EGFRm (2 years: 87 % vs 91 %-94 %; 4 years: 56 % vs 73 %-82 %). CONCLUSION: Approximately-one-quarter of patients with resected, early-stage NSCLC were EGFRm-positive in this study. These patients had high recurrence rates and suboptimal long-term survival after treatment with current therapies. New adjuvant treatments are warranted.

Treatment patterns and outcomes in early-stage ALK-rearranged non-small cell lung cancer.

INTRODUCTION: We evaluated the baseline demographics, treatment patterns, and outcomes of patients with ALK-rearranged early stage (Stage I-III) non-small cell lung cancer (NSCLC). We also evaluated the efficacy and toxicity of durvalumab consolidation treatment in patients with ALK-rearranged unresectable stage III disease. METHODS: Retrospective chart-review analysis of all patients with histologically confirmed stage I-III reflexively tested ALK-rearranged NSCLC managed with curative intent at two Canadian Centers. RESULTS: Of 48 patients, 19 (40%) were stage I, 5 (10%) were stage II and 24 (50%) were stage-III. Median progression-free survival (PFS) was 27.6 months overall (95%CI: 20.5-51.4) and 144.4 months in stage-I, 27.6 months in stage-II and 14.9 months in stage III patients. Of 20 patients with unresectable stage-III disease treated with chemoradiation (9 also received durvalumab consolidation), 18/90% have relapsed. Median PFS was 10.9 months (95%CI:5.9-22.5). A non-significant trend toward improved PFS was seen in patients receiving additional durvalumab compared to patients treated with chemoradiation alone (median PFS, 12.5 vs 5.9 months, p = 0.16). Toxicity-related treatment modifications on subsequent first ALK-TKI at time of metastatic disease were needed in three (33%) patients who had received chemoradiation alone and two (29%) patients with consolidation durvalumab; no relevant pulmonary or hepato-toxicity was observed overall. CONCLUSION: Treatment strategies and PFS of patients with Stage I-III ALK-rearranged NSCLC are similar to patients without molecular driver alterations. Durvalumab consolidation treatment appears generally safe in patients with unresectable stage III ALK-rearranged disease; however, the degree of benefit of such an approach remains unclear.

Biology and patterns of response to EGFR-inhibition in squamous cell cancers of the lung and head & neck.

The identification of common molecular aberrations that drive cancer progression has led to targeted therapies that improve treatment efficacy in many tumor types. Epidermal growth factor receptor (EGFR) inhibitors have been used to treat both lung and head and neck cancers with squamous cell histology. These tumors often show high EGFR expression and/or increased gene copy number, but low incidence of the activating kinase domain mutations common to adenocarcinomas of the lung. In this manuscript, we review clinical trial data on EGFR-inhibitors in the treatment of squamous cell carcinoma (SqCC) of the lung and head and neck (SCCHN), including both efficacy and biomarker analyses. Although some efficacy with use of EGFR inhibitors is observed, the level of benefit varies within and across tumor types, and the predictive capacity of high EGFR protein expression and/or gene amplification, if any, is limited. Due to the lack of candidate biomarkers that consistently predict response to EGFR-inhibitor therapy across treatment setting and class of agent in SqCC of the lung and SCCHN, we explore the biology, genomics and patterns of response to EGFR-inhibitors to inform identification of potential biomarkers, highlighting several key molecules that have shown promise in preclinical studies and clinical trials across multiple cancer sites.