Incidence of bleeding and thrombosis among elderly patients (pts) undergoing systemic chemotherapy in advanced non-small cell lung cancer (NSCLC): An analysis of North Central Cancer Treatment Group (NCCTG) trials.

Abstract

e18093 Background: Elderly pts receiving platinum-based doublet chemotherapy for advanced NSCLC derive similar therapeutic benefit as younger pts. However, elderly pts experienced more bleeding without obvious survival benefit compared to younger pts when bevacizumab was added to a carboplatin paclitaxel doublet. We investigated the incidence risks of grade 3+ bleeding and thrombotic events in advanced NSCLC pts from NCCTG chemotherapeutic trials. Methods: Individual pt data from 10 trials (n = 698) were pooled. Incidence risks of grade 3+ treatment related thrombosis or hemorrhage were estimated for the entire cohort as well as by age group (grp) (< 65 vs. ≥ 65 year old [yo]) and by treatment grp (platinum-based regimen [PBR] or vascular endothelial growth factor inhibitors [VEGFI]). Logistic regression models (adjusted for age grp) were used to examine the relationship between treatment grp (PBR or VEGFI) and risk of grade 3+ events. Odds ratio (OR) and 95% confidence interval (CI) are reported. Results: 30% of pts received PBR, 20% received VEGFI, and 61% of pts were ≥ 65 yo. Overall incidence of grade 3+ thrombosis and grade 3+ hemorrhage was 3.3%, and 1.3% respectively. There were no significant differences in thrombotic events by age or treatment grp. Pts who received PBR were more likely to experience grade 3+ hemorrhage (2.4% vs. 0.8%; OR [95% CI] = 3.4 [0.9-13.5]). The risk was lower among pts ≥ 65 yo (age-specific OR was 4.9 in pts < 65 and 2.5 in pts ≥ 65 yo). Exposure to VEGFI increased the risk of hemorrhage (3.6% vs. 0.7%; OR [95% CI] = 5.2 [1.4-20.0]) though this was more marked in elderly (age-specific OR was 3.2 in pts < 65 and 7.8 in pts ≥ 65 yo). Among the 30% patients who received PBR (n = 207), addition of VEGFI further increased the risk of hemorrhage (incidence was 6.3% in VEGFI plus PBR pts and 0.7% in PBR only pts). Conclusions: PBR and VEGFI appear to increase the risk of bleeding in both younger and elderly pts. The risk of thrombotic events is not significantly affected. Due to the small effective sample size of this study, further exploration is needed for a definite conclusion. No significant financial relationships to disclose.