Association between the anatomic distribution of melanoma and sex

Background: Anatomic distribution of melanoma, thought to be different between men and women, has not been studied in the United States since the 1970s, although lifestyle and clothing habits have changed since then. Objective. To determine whether the anatomic distribution of melanoma varied between men and women at our institution in 2004 and in the 1970s, and to assess whether the anatomic distribution has changed over time. Methods: We recorded the body location of initial primary cutaneous melanomas and assessed other variables of interest for 152 patients seen in our clinic in 2004 and in 397 patients seen between 1972 and 1977. Logistic regression was used for analysis. Results. For the 2004 patients, males had an increased relative risk compared to females of developing a melanoma on their head and neck (relative risk ratio [RRR] = 3.33; P = .01). For the 1970s patients, this difference was not found, but males in the 1970s had higher odds of developing melanoma on their upper back, chest, and abdomen, while females in the 1970s had higher odds of developing melanoma on the upper extremity and lower extremity, particularly the lower legs and feet. Examining differences over time, we found that women in 2004 had a decreased relative risk of developing a melanoma on the lower extremities as opposed to the trunk as compared to the 1970s (RRR = 0.42; P < .01). We also found that women had increased odds of developing a melanoma on the chest in 2004 compared to the 1970s (OR = 2.65; P = .04), while men had increased odds of developing a melanoma on their lower legs in 2004 compared to the 1970S (OR = 3.18; P = .02). Limitations: The study was performed at a single academic center and the results may not generalize to all melanoma populations. There may be important unexamined confounders. Conclusions: There were significant differences between men and women in the anatomic distribution of melanoma in 2004 patients and in 1970s patients, but the nature of those differences changed over time.