High prevalence of hypothyroidism in male patients with cutaneous melanoma

A recent study reported a higher than expected prevalence of hypothyroidism among patients with cutaneous melanoma. To further characterize and validate those findings, we conducted a retrospective review of the prevalence of hypothyroidism among all consecutive patients diagnosed with cutaneous melanoma in the dermatology clinic at the Michael E. DeBakey VA Medical Center (VAMC) in Houston, Texas. To accomplish this task, the electronic medical records of all patients diagnosed with cutaneous melanoma at the VAMC from January 2001 through October 2004 were examined for signs of hypothyroidism. Data regarding the site of melanoma and age at diagnosis were obtained for these hypothyroid cases and for age- and gender-matched euthyroid controls from the same melanoma cohort. Among 156 cutaneous melanoma patients (151 male and 5 female), 8 (5.1 %) showed a history of hypothyroidism [7 of 151 male (4.6 %) and 1 of 5 female (20 %)]. The prevalence of hypothyroidism among the male melanoma patients was significantly higher than that reported for the general population. The prevalence data concerning hypothyroidism among our female patients was not considered evaluable due to the primarily male distribution of our study population. We conclude that hypothyroidism (excluding iatrogenic etiologies) is frequent among male patients with cutaneous melanoma. Our results further suggest that a subset of melanoma tumors may respond to hormones of the hypothalamus-pituitary-thyroid axis, raising many questions that could influence the diagnosis, care, and treatment of a subset of melanoma patients.