Adoption of Adjuvant Chemotherapy for Non-Small-Cell Lung Cancer: A Population-Based Outcomes Study

Purpose Since 2004, several clinical trials have demonstrated that adjuvant chemotherapy (ACT) improves survival in patients with early-stage non-small-cell lung cancer (NSCLC). Here, we evaluate the uptake of ACT and its impact on outcomes in the general population of Ontario, Canada. Methods All patients diagnosed with NSCLC in Ontario from 2001 to 2006 who underwent surgical resection (n = 6,304) were identified using the Ontario Cancer Registry. We linked electronic records of treatment to the registry. We described uptake of ACT and compared survival of all patients with surgically resected NSCLC diagnosed from 2001 to 2003 with patients diagnosed from 2004 to 2006. As a proxy measure of ACT-related toxicity, we evaluated hospitalizations within 6 months of surgery. Results Demographic, disease, and treatment-related characteristics did not differ between the 2001 to 2003 and 2004 to 2006 study cohorts. Over the study period, the proportion of patients receiving ACT increased from 7% (192 of 2,950 patients) to 31% (1,032 of 3,354 patients; P < .001). The proportion of patients admitted to hospital within 6 months of surgery remained stable and (36% in the 2001 to 2003 cohort and 37% in the 2004 to 2006 cohort). However, within 2 years of surgery, there was a 33% reduction in the proportion of patients admitted to hospital with metastatic disease (P < .001). During the study period, there was a substantial improvement in 4-year survival among surgically resected patients, from 52.5% (2001 to 2003) to 56.1% (2004 to 2006; P = .001). Conclusion There has been a rapid uptake of ACT for NSCLC, which was not associated with an increased rate of hospitalization. The adoption of ACT was associated with a substantial improvement in overall survival, suggesting that the benefits seen in clinical trials are generalizable to the general population.