Better-Than-Expected: A Review Finds Relatively Better Survival in Melanoma of Unknown Primary

Hensin Tsao, MD, PhD reviewing Bae JM et al. J Am Acad Dermatol 2015 Jan.

The recognition of better-than-formerly-expected prognosis in patients with these tumors is reassuring, but can we assume advanced disease is not involved?

Melanoma of unknown primary (MUP) constitutes a relatively small and clinically uncertain group of melanoma lesions. In the past, outcomes were expected to be similar to those of other advanced-stage melanomas. In this meta-analysis, however, investigators found better-than-expected outcomes associated with MUP.

To compare outcomes of MUPs with melanomas of known primary, the authors of this review scanned the literature and identified 18 studies (total, 2084 patients with unknown and 5894 with known primaries). Compared with patients with stage III melanoma of known primary, MUP patients had better survival (hazard ratio 0.83). Their survival was also better than patients with stage IV disease and known primary (HR, 0.85). In a review of 22 studies including 3312 patients with MUP, advanced stage and older age were factors associated with worse survival.

Citation(s):

Bae JM et al. Metastatic melanomas of unknown primary show better prognosis than those of known primary: A systematic review and meta-analysis of observational studies. J Am Acad Dermatol 2015 Jan; 72:59.