Use of glucosamine and chondroitin and lung cancer risk in the VITamins and Lifestyle (VITAL) cohort

Objective: Inflammation plays an important role in lung carcinogenesis. Epidemiologic studies have reported inverse associations of non-steroidal anti-inflammatory drug (NSAID) use and lung cancer risk. Previously, we found that ever use of glucosamine and chondroitin, which have anti-inflammatory properties, were inversely associated with lung cancer risk. After an additional year of follow-up, we further examined the association including frequency/duration of use, interaction with factors associated with inflammation, and lung cancer histology. Methods: Participants were members of the VITamins And Lifestyle cohort. Adults, aged 50-76 years, who were residents of western Washington State, completed a baseline questionnaire in 2000-2002 (n = 76,904). Participants were queried on their use of glucosamine and chondroitin, over the 10 years prior to baseline, and categorized as nonuser, low use <4 days/week or <3 years, or high use ≥4 days/week and ≥3 years. Lung cancer cases (n = 808) were ascertained through linkage to the Surveillance, Epidemiology, and End Results cancer registry. Results: High 10-year use of glucosamine [hazard ratio (HR), 0.77; 95% CI: 0.56-1.07; p trend = 0.04] but not chondroitin was associated with a reduction in lung cancer risk. The association with glucosamine was limited to adenocarcinoma (HR, 0.49; 95% CI: 0.27-0.90; p trend <0.01) and was not modified by NSAID use or smoking status. Conclusions: Our results for glucosamine use are similar to the prior human studies of NSAID use and lung cancer, both in magnitude and the limitation of the association to adenocarcinoma. Unlike NSAIDs, glucosamine has no known adverse effects. Although confirmatory studies are needed, glucosamine is an attractive candidate for lung cancer chemoprevention.