Salivary gland cancer and risk of subsequent skin cancer.

There are epidemiologic similarities between salivary and skin neoplasms that could be attributed to exposure to ultraviolet radiation. To explore further the etiologic parallels between these two types of cancer, we studied the multiple primary association between salivary gland cancer with that of other cancers known to be induced by ultraviolet light exposure, using data from the SEER program for 1973-1984. Because nonmelanoma skin cancers other than cancers of the lip are not routinely reported to the SEER registries, we specifically evaluated the associations with melanoma and lip cancers. Expected numbers of subsequent primaries (melanoma and lip) for the 904 white men and 784 white women with an initial salivary gland cancer were computed from incidence rates using the Connecticut Tumor Registry. There were significantly increased risks for subsequent lip cancer among men (RR = 8.7) and for melanoma among women (RR = 7.1). Among men there was also a significant association between an initial lip cancer and risk of subsequent salivary gland cancer (RR = 12.7). These observations, together with reported increases in incidence of these tumors, suggest a common etiology, which could partly be explained because of exposure to ultraviolet radiation.