PALO ALTO, CA — Genetic and environmental risk factors have been associated with the development of multiple primary melanomas (MPM) but a new study questioned whether those patients might have increased predisposition to developing internal malignancies.

The report published in the Journal of the American Academy of Dermatology sought to identify the risk of subsequent malignancies in MPM patients.1

Researchers from the VA Palo Alto, CA, Health Care System and Stanford University Medical Center analyzed multiple primary standardized incidence ratios for patients with one or more, two or more and three or more primary melanomas (PM) in the SEER database from 1973-2014.

Ultimately, they identified 223,799 patients with one or more, 19,709 with two or more and 3,995 with three or more PM, and found that risks of subsequent internal malignancy increased with number of PM, with observed to expected (O/E) ratios of 0.99, 1.14, and 1.23 (p<0.05) for patients with at least one, two and three PM respectively.

The study team reported that Internal malignancy was higher in younger MPM patients and those with superficial spreading melanoma

Most frequent malignancies among MPM patients included breast, prostate, thyroid, soft tissue, brain, kidney, non-Hodgkin’s lymphoma, and chronic lymphocytic leukemia. Results indicated that risk of subsequent cutaneous melanoma increased with O/E ratios of 8.09, to 22.52, to 41.03 (p<0.05) respectively.

While limited by incomplete SEER information about pigmentation phenotypes, histology, and treatments, study authors concluded, “Patients with MPM have increased risk of subsequent internal and cutaneous malignancies and may benefit from tight adherence to age-specific cancer screening.”

1. Cai ED, Swetter SM, Sarin KY. Association of multiple primary melanomas with malignancy risk: a population-based analysis of the Surveillance, Epidemiology, and End Results Program database from 1973-2014. J Am Acad Dermatol. 2018 Oct 1. pii: S0190-9622(18)32637-9. doi: 10.1016/j.jaad.2018.09.027. [Epub ahead of print] PubMed PMID: 30287320.