Study Finds Familial Risks of Second Primary Cancers for Patients With Malignant Melanoma

For patients with a malignant melanoma, second primary cancers (SPCs) appear more frequently if there is a prior family history of cancer, and this risk contributes to mortality, according to recent research.

The findings, published by JNCI Cancer Spectrum, used the Swedish Family-Cancer Database to evaluate the relative risks and causes of death in SPCs in patients with a malignant melanoma diagnosis between 1958 and 2015. A total of 35,451 patients with malignant melanoma were identified, and 3212 of them had received a subsequent diagnosis of SPC.

Researchers note that as survival rates improve among patients with malignant melanoma, this increases the likelihood that more patients will experience SPC.

“SPCs in patients with [malignant melanoma] account for 5.1% of all SPCs in Sweden and 3.9% in Germany,” the authors stated. “Patients with MM are at an increased risk of multiple MMs and at least 10 different types of other (discordant) SPCs. Multiple MMs signal increased familial susceptibility to MM, and multiple cancers, even the discordant ones, are often associated with genetic predisposition.”

The analysis revealed that familial relative risks were increased for second melanoma, squamous cell skin cancer, leukemia, bladder, ovarian, kidney cancer, cancer of unknown primary, nervous system, breast, lung, and prostate cancer. For each of these cancers, there was an excess of familial relative risks. Additionally, cause of death for malignant melanoma patients with SPC was found to be dependent on the cancer site, although SPC was determined to contribute to the deaths.

After 10 years of follow-up, the researchers noted that survival curves diverged with poorer survival for patients with SPC compared with those without a family history. The study acknowledged that other factors like therapy-related causes and environmental causes may have a role in causing SPC. However, the data in this study does not find a direct link to these risks, and instead just demonstrates the general increase in familial risk in families with multiple diverse cancers.

“In conclusion, we showed that second and higher order multiple primaries caused more than half of the deaths in MM patients with an SPC,” the author’s noted. “Family history of lung, ovary, kidney, bladder, and skin (SCC) cancer and leukemia more than doubled the risk of SPC. In agreement with previous reports, a family history of MM led to an almost 20-fold increased risk of second MM. Mortality was largely governed by the type of SPC.”

The researchers suggested prevention efforts of SPCs as a primary target, as well as a thorough family history following diagnosis of malignant melanoma, in order to improve survival for malignant melanoma patients.

Reference

Chattopadhyay S, Hemminki A, et al. Familial risks and mortality in second primary cancers in

melanoma. JNCI Cancer Spectrum. 2019;2(4):pky068. doi: 10.1093/jncics/pky068.