Effect of aprepitant on adherence to high-dose cisplatin-based chemotherapy.

Abstract

9078 Background: Treatment of locally advanced head and neck cancers (HNC) and gastroesophageal cancers (GEC) frequently consists of high-dose cisplatin, which is highly emetogenic. Our aims were to 1) explore the impact of aprepitant for improving adherence to cisplatin-based chemotherapy in HNC and GEC, 2) examine its effect on reducing chemotherapy-induced nausea and vomiting (CINV) and 3) determine if use of aprepitant changed after introduction of insurance coverage for this drug. Methods: Patients diagnosed with HNC or GEC in British Columbia, Canada from Jan 2008 and June 2011 and prescribed high-dose cisplatin were reviewed. Using regression models that adjusted for confounders, we evaluated the relationship between aprepitant use and treatment and outcome characteristics, such as number of chemotherapy cycles, prevalence of CINV, and recurrence and survival. Results: A total of 333 patients were identified: 162 HNC and 171 GEC patients of whom 80% were men, 44% were aged >/=60 years, 35% were smokers, and 42% were alcohol users. Aprepitant was prescribed in 49%, nausea and vomiting occurred in 64 and 24%, respectively, and completion of all planned cisplatin was 52%. Younger patients (55 vs 41%, p=0.01) and those with less tumor burden (64 vs 38%, p<0.01) were more likely to be given aprepitant. Individuals who received aprepitant were significantly less likely to experience CINV (p<0.01). Use of aprepitant differed between HNC and GEC patients (p<0.01); however, its use did not increase when insurance coverage of this agent was introduced (p=0.16). In multivariate analyses, aprepitant use was significantly associated with adherence to all planned cisplatin treatments (OR 2.33, 95% CI 1.27-4.25, p<0.01). In Cox regression, completion of all cisplatin cycles was significantly correlated with a lower risk of recurrence (HR 0.56, 95%CI 0.32-0.97 p=0.04) and a trend towards decreased death (HR 0.56, 95%CI 0.31-1.10, p=0.10). Conclusions: Aprepitant was associated with a reduction in CINV in both HNC and GEC patients and correlated with better adherence to high-dose cisplatin-based chemotherapy. Individuals who completed all planned cisplatin had improved outcomes, specifically a lower risk of recurrence from HNC and GEC.