NEW YORK - The risk of developing a primary malignancy of the salivary gland, bone, prostate, and other areas is significantly--and in some cases dramatically--increased following a cutaneous melanoma diagnosis.
That's according to research by Dr. Joshua Spanogle, a resident in the department of dermatology at the Mayo Clinic in Rochester, Minn., presented during an abstract session at the American College of Mohs Surgery annual meeting.
Dr. Spanogle looked at data from the Surveillance, Epidemiology and End Results database (SEER) from 1973 to 2003, which included "over 1.3 million person years of observation," he said.
A total of 151,996 patients were found to have a cutaneous melanoma diagnosis during that period; 16,591 (11%) of these patients had a second documented primary malignancy sometime in the next 120 months. That observed rate was 32% higher than what would be expected among a healthy population in that time period, he said.
Further analysis of the results revealed that particular cancers carried a significantly higher risk than others.
The most striking, perhaps not surprisingly, is for a second primary cutaneous melanoma: there were 3,923 through 120 months of follow-up, for a standardized incidence ratio of 8.99. "This is the 600-pound elephant in the room," said Dr. Spanogle.
But other cancers have high standardized incidence ratios (SIRs) as well. Salivary gland malignancies following carcinoma had a SIR of 2.18 overall. Prostate cancer had a SIR of 1.13 following melanoma. Breast cancer showed a SIR of 1.07. And soft tissue cancers, including malignancies of the heart, had a SIR of 2.80.
On the other hand, "Quite a few cancers had a decreased incidence following melanoma," said Dr. Spanogle, including cancer of the liver (SIR 0.77), lungs (0.83), cervix (0.57), and pharynx (0.61).
That could be because risk factors for melanoma are associated with higher socioeconomic status, like fair skin and intermittent high intensity UV exposure (tanning), said Dr. Spanogle. In contrast, risk factors for lung cancer and liver cancer are associated with comorbidities commonly found in lower socioeconomic patients, like smoking and hepatitis.
Moreover, according to Dr. Spanogle, the risks of secondary cancers of the prostate gland, bone, soft tissue, and salivary gland remained elevated throughout the study period, "implying no surveillance bias."
Instead, he speculated that the link could be genetic, and said that future research into the possibility is warranted.
Dr. Spanogle reported having no disclosures relevant to his presentation. He added that this study has been accepted for publication in the Journal of the American Academy of Dermatology.