Primary cutaneous melanoma. Prognostic classification of anatomic location.

BACKGROUND: Anatomic location has been identified by several investigators as a significant prognostic factor for patients with primary cutaneous melanoma (CM). However, the best determination of higher and lower risk sites is still controversial, and the biologic significance of tumor site in the course of primary CM is unknown. The aim of the present study was to identify higher and lower risk sites based on multivariate analysis.

METHODS: A series of 5093 patients with invasive primary cutaneous melanoma followed from 1970 to 1988 at four university centers in Germany was investigated using the multivariate Cox proportional hazard model to analyze the importance of anatomic location for survival probability.

RESULTS: The anatomic location was found to be a highly significant prognostic factor for patients with primary melanoma by multivariate analysis (P < 0.0001). An optimized classification into sites of higher and lower risk with respect to survival was evaluated by multivariate analysis controlling for the possible confounding effects of the other significant prognostic factors. Relative to the lower leg as the prognostically favorable baseline, the following locations were associated with a significantly higher risk of death caused by primary cutaneous melanoma: back and breast (thorax), upper arm, neck, and scalp (TANS regions). The lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as lower risk sites.

CONCLUSIONS: Anatomic location was confirmed as an independent prognostic factor for patients with primary cutaneous melanoma. The TANS regions were identified as high risk sites, and the lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as intermediate sites.