Blog | Monday, May 7, 2012

QD: News Every Day--Women with melanomas less likely to progress

Women have a 30% advantage over men in all aspects of the progression of localized melanoma, most likely caused by an underlying biologic sex difference, researchers reported.

Researcher looked at data from four adjuvant, randomized, controlled, phase III trials of the European Organisation for Research and Treatment of Cancer Melanoma Group to derive 2,672 patients with stage I/II disease: 48% men and 52% women.

At diagnosis, men were older, were more likely to have an ulcerated or thicker primary tumor, and more often had melanomas on the head, neck, or trunk and fewer melanomas on extremities.

Results were published early online at the Journal of Clinical Oncology.

Women had a highly consistent and independent advantage in overall survival (adjusted hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.59 to 0.83), disease-specific survival (adjusted HR, 0.74; 95% CI, 0.62 to 0.88), time to lymph node metastasis (adjusted HR, 0.70; 95% CI, 0.51 to 0.96), and time to distant metastasis (adjusted HR, 0.69; 95% CI, 0.59 to 0.81).

Subgroup analysis showed that the advantage was consistent across all prognostic subgroups (with the possible exception of head and neck melanomas) and in pre- and postmenopausal age groups. (Menopause was assessed by age, not by status: premenopausal, 45 years or less; unknown, 46 to 59 years; postmenopausal, more than 60 years.

The authors wrote, "This further refutes the first hypothesis of an explanation by behavioral differences. Therefore, it is likely that fundamental biologic sex differences, either tumor- or host-related, cause this female advantage."

Estrogens are often mentioned as a possible contributing factor, the authors noted, but for most end points, sex differences were equal in pre- and postmenopausal age groups, when estrogen levels drop significantly in women.

An editorialist commented that gender-based disparity is real, rather than a result of study artifacts, and that men consistently demonstrate lower awareness, resistance to screening, and less knowledge seeking behavior when it comes to skin malignancies.

To counter these factors, indications for sentinel lymph node biopsy should be different for men and women. Also, the editorial continued, "In this study, self-skin examination and physician performed skin examination (by both dermatologists and primary care physicians) were identified as complementary early detection strategies, particularly in older men, so promoting these practices and increasing men's skin cancer awareness and examination practices should be labeled as priorities."