Background: Despite clinical trials demonstrating improved survival with adjuvant chemotherapy (AC) for patients with American Joint Committee on Cancer stages I to III non-small cell lung cancer (NSCLC), it is unclear whether this survival benefit extends to broader populations. The current study evaluated patterns of AC use and examined the impact of AC on survival.
Methods: A retrospective analysis was conducted of patients in the Veterans Affairs Central Cancer Registry diagnosed with stages IB to IIIA NSCLC between 2001 and 2008. Descriptive statistics were used to examine patterns of AC use over an 8-year time period. Cox proportional hazards regression analyses were used to estimate hazards ratios (HR) and 95% confidence intervals (95% CIs) to compare mortality risk among patients treated with and without AC.
Results: Among 14,306 patients with stages IB to IIIA NSCLC, 4929 underwent surgery and 22% of these received AC. The percentages of patients diagnosed in 2001 through 2003, 2004 through 2005, and 2006 through 2008 receiving AC were 7.0%, 29.8%, and 29.5%, respectively. There was no survival benefit with AC noted for patients diagnosed between 2001 and 2003, but AC was associated with improved survival for the period between 2004 and 2005 (HR, 0.78; 95% CI, 0.67-0.91) and 2006 through 2008 (HR, 0.79; 95% CI, 0.69-0.91). Of those patients receiving AC, 89% received platinum-doublet chemotherapy. Carboplatin remained the most common agent, although cisplatin use reached 43% in the period between 2006 and 2008. The HR for cisplatin relative to carboplatin was 0.96 (95% CI, 0.80-1.15).
Conclusions: There was a significant increase in the use of AC between 2001 and 2008 and AC was associated with an improvement in overall survival.
Keywords: adjuvant drug therapy; non-small cell lung cancer; survival; veterans.
© 2014 American Cancer Society.