Platinum and etoposide with concurrent thoracic radiation is the standard treatment for LS-SCLC. Elderly pts are common, and may experience higher rates of adverse events (AEs) and have a worse outcome from this treatment.
IPD were collected from 11 phase 2 or 3 trials for LS-SCLC conducted by the US National Cancer Institute-supported cooperative groups activated from 1990 to 2010. Overall survival (OS), progression-free survival (PFS) and AEs were compared between pts age ≥ 70 years (elderly) and for pts < 70 years (younger). Unadjusted and adjusted hazard ratios (HRs) for survival time and CIs were estimated by univariate and multivariable frailty Cox models.
IPD from 1049 younger and 254 elderly pts were analyzed. In the univariate and multivariable models, elderly pts compared with younger pts had worse OS (HR of 1.40; 95% CI, 1.20 to 1.65 and 1.36; 95% CI, 1.15 to 1.59). Median OS in elderly and younger pts was 17.8 months and 23.5 months, respectively. In the univariate and multivariable models, elderly pts had worse PFS (HR of 1.23; 95% CI, 1.06 to 1.43 and 1.19; 95% CI, 1.03 to 1.39). Median PFS in elderly and younger pts was 10.6 and 12.3 months, respectively. Elderly and younger pts had a similar rates of all grade ≥ 3 AEs, but elderly pts had a statistically significantly higher rate of all grade ≥ 4 AEs (p < 0.01), hematologic ≥ 4 AEs (p < 0.01), and grade 5 AEs (8% vs 3%, p < 0.001). When specific AEs were analyzed, elderly pts experienced a higher rate of grade ≥ 3 dyspnea (p = 0.03), but a lower rate of grade ≥ 3 vomiting (p = 0.01) and esophagitis (p = 0.03). Elderly pts compared with younger pts completed treatment at a lower rate (p = 0.02), stopped treatment at higher rates due to adverse events (p = 0.02), patient refusal (p < 0.01), and death during treatment (p < 0.01).
Elderly pts with LS-SCLC experienced a worse PFS and OS, and experienced a statistically higher rate of grade 4 and 5 adverse events. Future trials should investigate methods to identify vulnerable elderly pts and reduce the toxicity of treatment.
Clinical trial identification
Legal entity responsible for the study
Tom Stinchcombe and Xiaofei Wang.
NIH grant: R21-AG042894.
All authors have declared no conflicts of interest.