Occupational disparities in tumor grade and cytosolic HMGB1 expression in renal cell cancer

Objectives We sought to examine occupational disparities in tumor grade and cytosolic expression of high-mobility group box-1 (HMGB1) among renal cell cancer (RCC) patients. Methods This retrospective study included 318 RCC patients with complete information on occupation and pathology in Kanagawa Cancer Registry (KCR). Longest-held occupations were grouped into manual workers (e.g., manufacturing, construction) versus "others." Odds ratios (OR) and 95% confidence intervals (CI) for high-grade histology were estimated by logistic regression, adjusted for age and sex. We also examined a sub-sample of 74 low-grade RCC inpatients to estimate the OR for positive cytosolic HMGB1 expression in manual workers, adjusting for age, sex, and other available covariates. Results High-grade tumors were more prevalent in manual workers compared to other occupations: 23.0% (14/61) versus 10.9% (28/257, p = .01) with an adjusted OR of 2.28 (95% CI, 1.11-4.69). In the sub-sample of low-grade RCCs, positive cytosolic HMGB1 expression was more prevalent in manual workers compared to other occupations: 71.4% (10/14) versus 38.3% (23/60, p = .03) with a sex- and age-adjusted OR of 3.76 (95% CI, 1.03-13.7). Conclusions Manual workers are associated with increased risks of high-grade renal cell tumors and cytosolic HMGB1 expression.