Having first-degree relatives diagnosed with melanoma increases a person’s risk of pleural and peritoneal mesothelioma, a new study shows. Researchers believe that this is likely because the two cancers share common driver mutations.
Other associations with having relatives with melanoma included cancer of unknown primary, acute myeloid leukemia, and multiple myeloma.
The study, “Risk of other Cancers in Families with Melanoma: Novel Familial Links,” was published in Scientific Reports.
Although family history of melanoma is a known risk factor for the disease, less is known about the possible familial associations with other cancers.
Studies have suggested that family history of melanoma increases the risk for breast and prostate cancer. In addition, the most common high-risk gene predisposing to melanoma, CDKN2A, is also known to be associated with pancreatic cancer. Other mutations, like inherited BAP1 mutations, while increasing the risk for melanoma, are more linked to rare cancers like uveal melanoma and mesothelioma.
Knowing which cancers are associated with family history of melanoma could provide useful information regarding genetic counseling and clinical management. Therefore, researchers at the German Cancer Research Center in Heidelberg used a novel approach to search for familial associations of melanoma with other cancers.
Using the Swedish Family-Cancer Database, the researchers assessed a total of 79,060 melanomas, 38,102 of which were in the offspring generation for which the risk was calculated.
Only 8.57 percent of melanoma patients had a family history. Among them, 3,007 had one affected family member (parent or sibling), 239 had two affected family members, and 21 had three or more affected family members.
Patients with one family member diagnosed with melanoma were more likely to develop prostate, testicular, kidney, skin, nervous system, and thyroid gland cancers, as well as non-Hodgkin’s lymphoma. Those with a first-degree relative diagnosed with multiple melanomas had increased risk for lung, breast, skin, small intestine, and bone cancers.
Finally, those with two or more affected first-degree relatives, although rare, were at increased risk for salivary gland, colorectal, pancreatic, nasal, breast, cervix, prostate, skin, and eye cancers. Myeloma, non-Hodgkin’s lymphoma, and leukemia were also more likely to occur in these patients.
In view of the recent findings suggesting an involvement of the BAP1 gene in both melanoma and mesothelioma, researchers tested the risk of mesothelioma when cutaneous melanoma had been diagnosed in family members.
Their findings revealed that those with one family member with melanoma were 55 percent more likely to develop mesothelioma in the pleura or in the mesothelium. In addition, subjects with two cases of melanoma in the family were 2.14 times more likely to develop mesothelioma, compared to those without family history of melanoma.
