MONTREAL The incidence of melanoma in the United States increased rapidly over a 10-year period, regardless of tumor thickness and socioeconomic status, reported Dr. Eleni Linos.
"This has implications for preventive screening and primary care," she said at the annual meeting of the Society for Investigative Dermatology.
Dr. Linos and her coinvestigators examined data from the Surveillance, Epidemiology, and End Results (SEER) registry between 1992 and 2004 (J. Invest. Derm. 2009 Jan. 8 [doi:10.1038/jid.2008.423
During the study period, the incidence of melanoma of all thicknesses increased from 18 per 100,000 in 1992 to 26 per 100,000 in 2004an annual increase of 3%, said Dr. Linos of Stanford (Calif.) University. The steepest increase was seen in men aged 65 years and older, in whom the incidence rose from 73 to 126 new cases per 100,000. "The vast majority of melanomas that are diagnosed are thin, and that is why we have not seen such a dramatic increase in mortality rates," she explained. Overall mortality rose by 0.4% annually.
Melanoma trends were examined according to socioeconomic status to determine whether the findings could be explained by better screening in those with a higher status. Similarly, tumor thickness was examined to determine whether the increased incidence could be explained by more diagnoses of thin, clinically insignificant tumors.
"We found parallel increases across all socioeconomic groups and thicknesses, representing a true increase in clinically significant tumors," she said.