Retrospective Cohort Study of Unresectable Stage III Non-Small-Cell Lung Cancer in Canada

Background: The management of unresectable stage iii non-small-cell lung cancer (NSCLC) is complex and best determined through multidisciplinary consultation. A longitudinal, population-level study was carried out to describe the management approach and outcomes of treatment in the real-world setting in Ontario. Methods: Individuals diagnosed with nsclc between 1 April 2010 and 31 March 2015 were identified in the Ontario Cancer Registry. Unresectable disease was defined as no surgery reported within 3 months of diagnosis. Initial treatments included radiotherapy (RT, curative or palliative), chemotherapy, targeted therapy, and chemoradiation [CRT, concurrent (cCRT) or sequential (sCRT)]. Survival was calculated from diagnosis with stage III disease to death or last follow-up. Results: Of the 24,729 individuals diagnosed with nsclc, 5243 (21.2%) had stage iii disease, with most of the latter group (4542, 86.6%) having unresectable disease. Median age was 70 years, and 54.2% were men. The frequency of first-line treatment was cCRT, 22.1%; palliative rt, 21.0%; curative rt, 19.6%; no treatment, 19.6%; chemotherapy alone, 11.6%; sCRT, 5.4%; and targeted therapy, 0.7%. Median overall survival (mOS) was 14.2 months [95% confidence interval (CI): 13.6 months to 14.7 months], with the longest survival observed in patients who received targeted therapy (mOS: 34.7 months; 95% CI: 21.4 months to 51.2 months), and the poorest, in those receiving no cancer treatment (mOS: 5.9 months; 95% CI: 5.0 months to 6.4 months). The mOS in patients receiving cCRT was 23.6 months (95% CI: 21.4 months to 25.6 months). Conclusions: Guideline-recommended cCRT is undertaken in only a small proportion of patients with unresectable NSCLC in Ontario. The reasons for low uptake of that recommendation are only partly understood.