Association between patient medications and postoperative outcomes in early-stage non-small cell lung cancer.

Abstract

Background: Currently, there is no consensus on how to comprehensively assess comorbidities in lung cancer patients in the clinical setting. Prescription medications may be a preferred comorbidity assessment tool and provide a simple mechanism for predicting postoperative outcomes for lung cancer. We examined the relationship between prescription medications and postoperative outcomes for early-stage non-small cell lung cancer (NSCLC).

Methods: We conducted a retrospective cohort study of patients with clinical stage I NSCLC who underwent surgical resection in the Veterans Health Administration (VHA) between 10/01/2006 and 09/30/2016. Details of all outpatient prescriptions filled by patients within the VHA system from 1-year up to 14 days before surgery were collected. Medications were categorized using the Anatomical Therapeutic Chemical (ATC) Level One classification system. We assessed the association of medications prescribed in the year prior to surgery with postoperative adverse events (composite of death or major complication) at 30 and 90 days following surgery and overall survival (OS).

Results: We included 9,741 veterans in the analysis. The median number of prescription medications filled in the year preceding surgery was 11 (interquartile range: 7-16). In multivariable-adjusted analyses, a higher number of prescription medications was associated with increased risk of 30-day [multivariable-adjusted odds ratio (aOR): 1.016; 95% confidence interval (CI): 1.007-1.026] and 90-day postoperative adverse events (aOR: 1.015; 95% CI: 1.006-1.024) and decreased OS (adjusted hazard ratio: 1.019; 95% CI: 1.014-1.023). Within a subgroup of patients with a high comorbidity burden (Charlson-Deyo Comorbidity Index score of 6-8), a higher number of prescription medications was also associated with reduced OS (P<0.001). Patients prescribed medications from the ATC respiratory system class had elevated risk of postoperative adverse events at 30 days (aOR: 1.255; 95% CI: 1.095-1.439) and 90 days (aOR: 1.254; 95% CI: 1.097-1.434) compared to patients without these prescription medications. Significantly increased odds for 90-day postoperative adverse events were observed with each additional prescription medication from the ATC respiratory (aOR: 1.057; 95% CI: 1.027-1.088) and nervous system (aOR: 1.035; 95% CI: 1.005-1.066) classes.

Conclusions: The number of medications prescribed preoperatively is associated with short- and long-term postoperative outcomes for early-stage NSCLC, even when adjusting for several covariates including age and comorbidity burden. Patients prescribed a higher number of medications acting primarily on the respiratory and nervous systems are at elevated risk for postoperative adverse events after curative-intent resection. Prescription medications may be a reliable tool to assess comorbidities and perioperative risk for patients with NSCLC.