Retrieval from the cancer registry generated an identical number (seven) of melanoma and nonmelanoma skin cancers; this suggests that records were incomplete.
Kubasiewicz and Starzynski (1989) described the methods used to identify and interview men who had incident cases of skin cancer from 1982 through 1988 in the registry for Lodz, Poland, and age-matched sets of population and hospital controls. With selection for “all skin lesions suspected to have a neoplastic origin”, they reported that the 374 interviewed cases (of the 520 identified cases born after 1900) had 278 basal-cell carcinomas, 70 “carcinomas planoepitheliale”, 13 cases of Bowen’s disease (carcinoma in situ, precancerous), and 13 cases of Arning’s carcinoid (superficial basal-cell carcinoma). In an analysis that focused on occupational exposure to PAHs, Kubasiewicz et al. (1991) reported on a final set of 376 cases and their 752 population and 752 hospital controls. Full work histories were gathered, but the exposures analyzed consisted of self-reports on each of 17 possible agents, three of which would fit in our fuels classification: petroleum, petrol, and gasoline. The distinction between petrol and gasoline was not stated, but the results for gasoline exposure were said to be too sparse to analyze. Minor increases in crude risks of skin cancer were reported for both petroleum and petrol (ORs 1.17 and 1.30, respectively). The definition of skin cancer used in the study clearly excluded melanoma, but it did encompass some skin lesions that do not coincide with the malignant classification the present committee intended to address.
Using the Alberta (Canada) Cancer Registry, Gallagher et al. (1996) identified all men with squamous-cell carcinoma and basal-cell carcinoma who were 20–79 years old when diagnosed in 1983–1984. All 225 subjects with a first primary squamous-cell carcinoma were eligible. For first primary basal-cell carcinoma, only one-fourth of the cases with the lesion on the head or neck were retained, but all subjects with such a tumor elsewhere were kept; the total was 314 eligible cases of basal-cell carcinoma. During home interviews, 180 men with squamous-cell carcinoma and 226 men with basal-cell carcinoma completed a questionnaire that included a complete work history and a list of specific exposures of interest. Of 573 age-matched controls with no history of skin cancer drawn from men in the Alberta Health Care Insurance Plan (which includes everyone resident in the province for more than 3 months), 406 men completed the same questionnaire. The sets of squamous-cell carcinoma and basal-cell carcinoma cases were compared with the controls separately. With adjustment for age, skin pigmentation (for example, fair skin), ethnicity, and exposure to sunlight, but not smoking, the risk of squamous-cell carcinoma after exposure to petroleum products (specified to be gasoline and oil) was increased (OR 1.3, 95% CI 1.0–2.0), but not the risk of basal-cell carcinoma (OR 0.9, 95% CI 0.6–1.3). Although the response rates were low and the exposure data came only from self-reports, the results of the study suggest a potential relationship between exposure to petroleum-derived fuels and squamous-cell carcinoma.
Table 4.24 presents the most relevant findings reviewed by the committee in drawing its conclusion on the possibility of an association between exposure to combustion products and nonmelanoma skin cancers.