Descriptive epidemiological findings for 7,696 patients with newly diagnosed thyroid cancer reported to the Surveillance, Epidemiology, and End Results (SEER) program for the years 1973 through 1981 are summarized. The preponderance of this tumor in women and of the papillary histologic subtype are well documented. The data suggest that previously reported increases in the incidence of thyroid cancer among Whites levelled off in the late 1970s. Differences in the incidence of this cancer according to ethnic group were particularly striking. Compared with White men and women, Puerto Rico Hispanics and Blacks had significantly lower thyroid cancer rates (weighted rate ratios ranged from 0.48 to 0.65). New Mexico Hispanic men and Chinese, Japanese, Hawaiian and Filipino men and women had significantly higher rates (weighted rate ratios ranged from 1.56 to 3.17). Elevated thyroid cancer rates for residents of Hawaii, regardless of ethnic group, were also a noteworthy finding. Variations in thyroid cancer risk according to ethnic group and geographical residence may reflect socio-economic or local environmental influences, including the possibility of a carcinogenic agent in volcanic lava.

Using the data base for melanoma incidence compiled by the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, we compared the incidence and anatomic distribution of primary cutaneous melanomas in Hispanic and non-Hispanic Caucasian populations and in blacks between 1973 and 1981. Cases were divided into United States whites, New Mexico (NM) whites (non-Hispanic Caucasians), NM Hispanics, Puerto Rico (PR) residents by definition Hispanic, and US blacks. Among whites, the highest incidence was 8.0 per 100,000 and was ten times that of US blacks. The incidence among PR and NM Hispanic residents was 1.6 to 3.7 times that of US blacks. The anatomic distribution among NM Hispanics was similar to US and NM whites for both genders. In contrast, among PR residents the anatomic distribution in both genders was most common for the leg, similar to that for blacks. Spaniards who migrated to PR have more admixture with blacks from Africa than Spaniards who migrated to the mainland. This suggests a genetic predilection for the occurrence of melanoma on the lower extremity among PR residents as opposed to NM Hispanics.

Cancers of the cervix and buccal cavity share histologic, epidemiologic, and exposure characteristics. In particular, cigarette smoking and human papillomavirus (HPV) have been cited as etiologic cofactors of both malignancies. Using incidence data from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute for the years 1973 through 1984, we evaluated the incidence of second cancers of the buccal cavity following an initial cervical cancer. Standardized incidence ratios (SIR) were uniformly elevated for both white (SIR = 2.0), and black (SIR = 3.5) women. There were also elevated risks for the development of cervical cancer following an initial buccal cavity cancer (SIRs = 3.3 and 2.5, respectively). A similar pattern was evident for laryngeal cancer among white women. HPV transmission could account in part for the paired occurrence of these two anatomically distinct cancer sites. Cigarette smoking could act as a synergistic cofactor in the malignant transformation of viral genome-harboring tissue.

This is a descriptive epidemiologic report based on over 3000 incident testicular cancer cases occurring among residents of the US and h e r t o Rico, as reported to the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute for the years 1973 through 1982. White men had significantly higher incidence rates than their New Mexico Hispanic, black, and Puerto %can Hispanic counterparts with weighted risk ratios of 1.36,4.62, and 4.80, respectively. Ethnic differences in incidence were least evident at the extremes of age. Although the distribution of histologic subtypes did not differ across ethnic strata, morphologic expression was related to age at diagnosis. There was a predominance of right-sided tumor involvement in each ethnic group in childhood (<15 years of age), but not in the oldest age categories or among tumors presenting in cryptorchid testes. Never married men appeared to be at greater risk of developing nonseminoma testicular cancer than their married counterparts. Analysis of ethnic secular trends, using data from comparable geographic areas, showed a consistent increase in incidence among young men for all three ethnic groups. The contrast between the rate differences and the homogeneity of descriptive parameters across ethnic strata suggest the impact of quantitative rather than qualitative differences in environmental etiology.

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.