The risk for malignant primary adult-onset glioma in a large, multiethnic, managed-care cohort: cigarette smoking and other lifestyle behaviors.

PURPOSE

To determine the risk for malignant primary adult-onset glioma (MPAG) associated with cigarette smoking and other lifestyle behaviors in a large, multiethnic, managed-care cohort.

METHODS

The study population included a cohort of 133,811 subscribers to the Kaiser Permanente Medical Care Program of Northern California who had received a multiphasic health checkup and questionnaire between 1977 and 1985, were at least 25 years old at their start of follow-up, and had no prior history of benign or malignant brain tumors. In this cohort, patients were followed for up to 21 years for the development of MPAG.

RESULTS

Risk for MPAG among women increased with increasing packs of cigarettes smoked per day (p-for-trend = 0.04), adjusting for cigar and pipe smoking, patient age, sex, race, education, alcohol use and coffee consumption. A similar pattern was not observed for men. Individuals who smoked marijuana at least once a month, adjusting for cigarette smoking (packs smoked per day) and for the factors noted above, had a 2.8-fold (CI = 1.3-6.2) increased risk for MPAG. Relative risk for MPAG increased with increasing consumption of coffee (p-for-trend = 0.05).

CONCLUSIONS

Cigarette smoking was associated with an increased risk for MPAG among women but not among men. Individuals who smoked marijuana at least once a month had an increased risk for MPAG, although no dose-response relation was observed. Drinkers of >7 cups of coffee per day had a 70% increased risk for MPAG and smaller risk elevation for lower consumption. Alcohol usage was not associated with an increased risk for MPAG.