Older Men More Likely to Develop Multiple Primary Melanomas

Older men are more likely to be diagnosed with multiple primary melanomas and have worse disease–specific survival than men with a single primary melanoma, according to a new study presented at the Society for Melanoma Research (SMR) 2015 International Congress, held November 18–21 in San Francisco.

Multiple primary cutaneous melanomas are diagnosed in a proportion of patients with cutaneous malignant melanoma. The impact on disease–specific survival is not well characterized, noted Hanna Eriksson, MD, PhD, of the department of oncology-pathology at the Karolinska Institute in Stockholm, Sweden.

Dr. Eriksson and colleagues aimed to describe the clinical characteristics and survival in multiple primary melanoma patients compared to single primary melanoma patients, including possible gender differences.

They identified 27,235 patients diagnosed with an invasive, primary cutaneous malignant melanoma in Sweden between 1990 and 2007. Some 700 patients developed two or more cutaneous malignant melanomas during the study period and were defined as multiple primary melanoma patients.

Data were linked to nationwide, population-based health and census registers and followed through 2012. Clinical characteristics were compared between both patient groups.

The researchers found that men comprised a significantly higher proportion of multiple primary melanoma patients compared with single primary melanoma patients (60% vs 49%). The multiple primary patients were significantly older at diagnosis as well, with a median age of 64 years compared with 62 years among those with single primaries.

In the multiple primary melanoma group, the vast majority were diagnosed with two cutaneous malignant melanomas. The index tumor was the most advanced in more than two-thirds of these patients. Their median time between diagnosis of the first and second melanoma was 1.4 years.

The multiple primary patients had a reduced disease–specific survival compared to single primary patients that reached statistical significance. “We found the risk of cutaneous malignant melanoma–specific death increased by 57% with the diagnoses of a second melanoma,” Dr. Eriksson said.

After full adjustment for prognostic factors and potential mediators, the risk of cutaneous malignant melanoma–specific death was significantly increased in men with multiple primary melanomas compared to men with a single primary melanoma. This difference was not seen among women.

Men aged 70 and older diagnosed with multiple primaries had an increased risk of disease–specific death compared to men with a single primary melanoma.

A significant association was found with the interval between cutaneous malignant melanoma diagnoses, with an increased risk of cutaneous malignant melanoma death in patients with a second melanoma within 5 years from diagnosis of the index tumor.

A high level of education was also associated with a significantly higher risk of being diagnosed with a second cutaneous malignant melanoma.

In conclusion, Dr. Eriksson said that the results “emphasize the need for improved early detection strategies and follow-up specifically targeting patients at risk for multiple primary melanomas.”