Early Melanoma: Low Risk of Mortality

The findings could indicate that some patients currently classified as melanoma may not face the same risks traditionally associated with melanoma.

Although melanoma is the most serious type of skin cancer, most patients have a high chance of surviving the disease. There is evidence that more cases of melanoma are being overdiagnosed in patients who would never experience symptoms.

Using cancer registry data, researchers identified a subset of early-stage melanoma patients with almost no melanoma-related deaths, which could represent cases contributing to overdiagnosis. The research, which Wiley publishes online in CANCER , a peer-reviewed journal of the American Cancer Society, may help doctors determine which patients have a very low risk of death from melanoma after removing the growth.

For the study, Megan M. Eguchi, MPH, of the University of California, Los Angeles; Kathleen F. Kerr, PhD, of the University of Washington; David E. Elder, MB, ChB, FRCPA, of the University of Pennsylvania; and colleagues analyzed data from the US Surveillance, Epidemiology, and End Results (SEER) database on patients who were diagnosed in 2010 and 2011 with stage 1 melanoma that was 1.0 mm or less thick. and had not spread to the lymph nodes. Models were developed to identify patients with a very low risk of dying from melanoma within 7 years, as well as those with a higher risk of death.

Among the 11,594 patients in the analysis with follow-up data, the overall 7-year melanoma mortality rate was 2.5%. However, the models identified a subset of 25% of patients in the large cohort with a risk of less than 1%.

These patients tended to be younger and their cancers had minimal skin invasion. A very small subgroup of patients (less than 1%) who were older and had slightly more advanced tumors (although considered low risk by current criteria) had a risk of death greater than 20%, and these patients may be considered so that they can save their lives, more complex therapy.

The findings show that a subset of melanoma patients with a very low risk of death can be identified using some standard risk factors. It is hoped that the findings of this study can be used as a starting point for future research using additional study designs and variables beyond those available in the SEER database to further improve this classification.

"Given the very low risk of death from melanoma associated with some of the cases identified in this study, and if these findings can be verified and perhaps expanded in other studies, the use of a different term such as ’melanocytic neoplasm of low malignant potential’ may be more appropriate than melanoma, as has been done with some other neoplasms or tumors previously labeled as cancers," Dr. Elder said. "Such a term can potentially alleviate people’s concerns related to prognosis and outcomes and begin to address the problem of overdiagnosis."