Salivary gland cancer. A case-control investigation of risk factors.

Unlike most upper aerodigestive tract cancers, salivary gland cancers are relatively infrequent, are characterized by a diversity of histologic subtypes, and have never been etiologically associated with tobacco exposure. We present the results of a case-control study of risk factors for these cancers, with risk estimates derived from self-administered comprehensive risk-factor questionnaires distributed to patients at The University of Texas M. D. Anderson Cancer Center, Houston. Cases were 64 patients with histologically confirmed salivary gland cancer. Control subjects, randomly selected from the same patient population excluding patients with cancer of the head and neck or nonmelanoma skin cancer, were frequency-matched to the cases by age, sex, and ethnicity to achieve a 2:1 control subjects/cases ratio. On multivariate analysis, prior radiotherapy was a significant risk factor for both men (odds ratio [OR] = 2.1) and women (OR = 2.3). Among women, higher educational attainment (OR = 2.4), alcohol use (OR = 2.0), and hairdye use (OR = 2.5) were also significantly associated with risk. There were no significant differences between cases and control subjects with respect to tobacco exposure or specific occupational or leisure-time exposures. There is biological plausibility for associations with hairdye use and alcohol exposure.