Anal squamous intraepithelial lesions (ASIL) are common in homosexual and bisexual men, and high-grade ASIL (HSIL) in particular may represent an anal cancer precursor. Cervical cytology is a useful screening tool for detection of cervical HSIL to prevent cervical cancer. To assess anal cytology as a screening tool for anal disease, we compared anal cytology with anoscopy and histopathology of anal biopsies. A total of 2958 anal examinations were performed on 407 HIV-positive and 251 HIV-negative homosexual or bisexual men participating in a prospective study of ASIL. The examination consisted of a swab for anal cytology and anoscopy with 3% acetic acid and biopsy of visible lesions. Defining abnormal cytology as including atypical squamous cells of undetermined significance and ASIL, the sensitivity of anal cytology for detection of biopsy-proven ASIL was 69% (95% confidence interval: 60 to 78) in HIV-positive and 47% (95% confidence interval; 26 to 68) in HIV-negative men at their first visit and was 81% and 50%, respectively, for all subsequent visits combined. The absence of columnar cells did not affect the sensitivity, specificity, or predictive value of anal cytology. Anal cytology may be a useful screening tool to detect ASIL, particularly in HIV-positive men. The grade of disease on anal cytology did not always correspond to the histologic grade, and anal cytology should be used in conjunction with histopathologic confirmation.

Using individual subject data from 10 case-control studies, comprising over 3000 cases and almost 4000 controls, we have estimated the relative risk of melanoma associated with aspects of complexion, namely, hair, eye and skin colour and freckling in adulthood, and have examined the relationships between these factors and naevus count in terms of melanoma risk. Compared with individuals with black or dark brown hair, the relative risks for developing melanoma in those with light brown, blonde and red hair were 1.49 (95% CI 1.31, 1.70), 1.84 (95% CI 1.54, 2.21) and 2.38 (95% CI 1.90, 2.97), respectively. Individuals with blue eyes had a risk 1.55 (95% CI 1.35, 1.78) times that for those with brown eyes, or 1.15 (95% CI 0.94, 1.40) after adjusting for hair colour and freckling in adulthood. The relative risks associated with hair and eye colour were independent of those for naevus count and skin colour. Light skin colour and high freckle density were also highly significant risk factors, independent of each other and of naevus count and hair and eye colour. The risks associated with these factors, while individually modest, are largely independent, and thus pigmentation characteristics and freckling tendency should be useful in identifying high risk groups to be targeted for prevention.

We conducted a case-control study in the western United States to determine the relation between occupations or chemical exposures and increased risk of uveal melanoma. Among men (221 patients, 447 controls), we found increased risks for occupational groups who had intense exposure to ultraviolet light [odds ratio (OR) = 3.0; 95% confidence interval (CI) = 1.2-7.8], welding exposure (OR = 2.2; 95% CI = 1.3-3.5), and asbestos exposure (OR = 2.4; 95% CI = 1.5-3.9 for most likely exposed). The highest odds ratio was for the small number of men (nine cases, three controls) who were chemists, chemical engineers, and chemical technicians (OR = 5.9; 95% CI = 1.6-22.7). Odds ratios also were elevated for exposures to antifreeze, formaldehyde, pesticides, and carbon tetrachloride, but these findings, based on recall of specific chemical exposures, are more subject to recall bias than the findings based on occupational groups.

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