Factors associated with receipt and overall survival of concurrent chemoradiotherapy versus single modality therapy in unresectable stage III NSCLC.

Abstract

e18191 Background: While concurrent chemoradiotherapy (cCRT) is standard of care for patients (pts) with unresectable stage III non-small cell lung cancer (NSCLC), some pts receive single modality therapy. This study identified predictors of therapy and differences in overall survival (OS) in a Medicare population. Methods: This retrospective study used Surveillance, Epidemiology and End Results -Medicare data (2009-2014). Stage III NSCLC pts aged ≥65 yrs, with ≥1 claim for systemic therapy or radiotherapy (RT) within 90 days of diagnosis were included. cCRT pts had overlapping claims for chemotherapy and RT ≤90 days from start of therapy; remaining pts were grouped by first therapy received. Sequential CRT patients and those with surgical resection of tumor were excluded from this analysis. Logistic regression was used to analyze predictors of cCRT. Multivariable Cox proportional hazards models were used to compare OS between therapies. Results: Of 4,544 pts identified, 51% received cCRT, 21% systemic therapy, and 27% RT. Across groups, cCRT patients were likely younger (p < 0.001), White (p < 0.001), male (p = 0.015), and with a good predicted performance status (PS) (p < 0.001). After adjustment, several variables were predictive of receiving cCRT (Table). Median OS was 14.7 months (mo) for cCRT vs. 10.9 mo for systemic therapy (adjusted hazard ratio [HR]: 1.36, 95% CI: 1.24-1.49, p < 0.001) vs. 7.8 mo for RT (adjusted HR: 1.55, 95% CI: 1.42-1.69, p < 0.001). Conclusions: Only 51% of pts received cCRT. Age, race, stage, PS and comorbidity index were predictive of cCRT. Given the survival benefit, physicians should be encouraged to pursue cCRT in all eligible pts. Further efforts to develop less morbid therapies are critical in this population. [Table: see text]