Letter to the editor

Scand J Work Environ Health 1997;23(4):308    pdf

https://doi.org/10.5271/sjweh.224 | Issue date: Aug 1997

Re: "Malignant melanoma among lithographers" by H Nielsen, L Henriksen, JH Olsen. Scand J Work Environ Health 1996;22:108--11

by Carlton BD, Shah H

In a recent article in the Scandinavian Journal of Work, Environment & Health (1), Nielsen et al reported a higher incidence of malignant melanoma among lithographers and suggested that hydroquinone may be implicated in the observed increased risk. Overall, there was a nonsignificant decrease in the relative risk for cancer (24 versus 26.2 cases expected). In this population, 5 cases of malignant melanoma versus 1.5 were expected. The authors have suggested that exposure to hydroquinone, which is used as developer, may be associated with the higher incidence of melanoma. The suggested link between hydroguinone and melanoma is presumed because hydroquinone is known to reduce pigmentation when applied chronically to skin. There are, however, epidemiologic data which suggest that hydroquinone exposure does not result in melanoma and experimental data that hydroquinone may be antineoplastic toward melanoma. Chavin et al (2) and Chavin & Abramowitz (3) have shown that hydroguinone can, under certain circumstances, inhibit or destroy melanoma cells in vitro and in vivo. In a study in which mice were injected with NIH Harding Passey melanoma cells and given hydroquinone, the incidence of successful transplantation was reduced, and, although host survival was not elucidated, both the pharmacologic and the toxicologic effects of hydroquinone on melanoma cells may play significant roles (3). Of greater relevance to hydroquinone exposure in the workplace is the report of Pifer et al (4) on the mortality experience of 879 men and women working in a hydroquinone manufacturing plant. Overall cancer mortality in the cohort was significantly decreased (33 observed versus 57.9 expected, standardized mortality ratio 57, 95% confidence interval 39--80). In the combined category of "bone, connective tissue, skin and breast" 1 tumor versus 1.8 was observed, and this tumor was not a melanoma. Overall, we do not believe that the available data would support a link between hydroquinone exposure and an increased incidence of malignant melanoma in lithographers.

This article refers to the following text of the Journal: 1996;22(2):108-111