If you think you’ve been seeing more cases of malignant melanoma, you probably have.
A large-scale, population-based study reports significant increases for all histological subtypes and all tumor thicknesses between 1992 and 2004. Moreover, they reflect an actual growing burden not a statistical illusion, the researchers conclude.
“Our findings…show persistent increases among more fatal, thick tumors and contest the argument that rising incidence rates are solely attributable to increased diagnosis of thinner tumors,” they assert (J Invest Dermatol. 2009 Jan 8;[Epub ahead of print]).
Led by Eleni Linos, MD, PhD, a dermatologist at Stanford University Medical Center in Palo Alto, Calif., the team analyzed diagnoses of invasive melanoma among non-Hispanic whites obtained by the Surveillance Epidemiology and End Results (SEER) program. The data covered represented 291 million person years of data.
A total of 70,596 new cases of malignant melanoma were diagnosed in the 13 SEER areas across the country over the study period, yielding an overall increase of 45% during the 12 years or 3.1% each year. The incidence rate also rose significantly from 18.2/100,000 in 1992 to 26.3 in 2004.
Men aged >65 years showed the sharpest change. Rates of new cases rose from 73.2 in 1992 to 126.1 in 2004 “giving this group both the highest absolute rate, as well as the fastest annual percent change, 4.5%,” the study observes.