Melanoma and Nonmelanoma Skin Cancer in Patients with Multiple Tumours--evidence for New Syndromes in a Population-based Study

Background: The hypotheses that Swedish patients with four or more primary tumours [including at least one cutaneous malignant melanoma (CMM)] harbour an increased number of CDKN2A (formerly p16) germline mutations, and that this group of patients show a predisposition to other tumours, e.g. nonmelanoma skin cancer (NMSC), were studied descriptively. So far the mutation 113insArg explains all CDKN2A-associated CMM in ethnic Swedes.

Objectives: All patients with four or more primary tumours, of which at least one was a CMM, from the Southern Swedish Regional Tumour Registry, between 1958 and 1999, were included in this study.

Methods: Forty-four patients were found and subdivided into three groups according to having multiple CMM (group A) or single CMM +/- NMSC (groups B and C). Screening for the presence of the Swedish founder mutation 113insArg in blood or in tissue blocks was performed.

Results: Patients in group A were younger at the time of the first CMM diagnosis than patients in group B and group C. The 113insArg mutation was found in four of 44 patients (9%), three with multiple CMM. In group C (n = 14) no founder mutation was evident, while in group B (n = 15) one mutation carrier was found. Nonmutation carriers with multiple CMM (group A) also had a predilection for meningiomas and neurinomas (four patients) or multiple NMSC (three patients). In group B CMM were especially associated with adenocarcinomas but in group C CMM were associated with multiple NMSC.

Conclusion: The association between meningiomas and neurinomas (no acoustic neurinoma was seen) might indicate a new syndrome. Patients in groups B and C may harbour unknown genetic defects, which could interact with different environmental risk factors.