Black and Hispanic patients in Florida's Miami-Dade County are more likely than white patients to have a more advanced stage of melanoma at the time of diagnosis of the disease, according to a report published in the June issue of the Archives of Dermatology, one of the JAMA/Archives journals.
The skin cancer melanoma has become increasingly more common, with incidence rates increasing 2.4 percent annually in the United States over the past decade, according to background information in the article. Because light-skinned individuals are at higher risk for melanoma, much of the prevention and early detection efforts have targeted white populations; this may help explain improving survival rates (up to 92 percent from 68 percent in the 1970s) among whites. However, similar progress has not been seen among black and Hispanic populations.
Shasa Hu, M.D., University of Miami Miller School of Medicine, and colleagues reviewed 1,690 melanoma cases reported in Miami-Dade County between 1997 and 2002. Of those, 1,176 occurred in white patients, 485 in Hispanic patients and 29 in non-Hispanic black patients.
Hispanic and black patients were both more likely to have advanced-stage melanomas than white patients. Of the melanoma patients, 16 percent of Hispanics and 31 percent of blacks had cancer that had already metastasized (spread to other organs and tissues) at the time it was diagnosed, compared with 9 percent of whites. Black patients had the highest rate, 52 percent, of regional- or distant-stage melanoma, the two most severe stages that indicate the cancer has spread to other lymph nodes or organs; this compares to 26 percent for Hispanics and 16 percent for whites. White patients were more likely to be diagnosed with earlier stages of melanoma, including melanoma in situ, or cases in which the cancer cells are found only in the outer layer of skin, and local melanoma, in which cancer has spread to the lower layers of skin but not to the surrounding lymph nodes. Twenty-seven percent of white patients, 10 percent of black patients and 22 percent of Hispanic patients were diagnosed with melanoma in situ; 57 percent of white, 38 percent of black and 52 percent of Hispanic cases were diagnosed at the local stage.
This disparity in stage at diagnosis may contribute to lower survival rates among blacks and Hispanics, the authors write. According to previously published studies, the five-year survival rate for melanoma diagnosed in the local stage is 98 percent. The rate drops to 64 percent for regional stage melanoma and 16 percent for distant stage.
"Evidence suggests that secondary prevention efforts such as skin cancer examination are suboptimal in Hispanic and black populations," the authors conclude. "Although varying cultural values may account for some differences in health care use, public education regarding melanoma risk in black and Hispanic persons and delivery of skin cancer screening and examinations represent the main potential areas of intervention to improve the stage at diagnosis of melanoma in these populations. We hope that earlier diagnosis of melanoma at a more favorable stage will ultimately improve melanoma survival rates in minority populations." (Arch Dermatol. 2006;142:704-708)
Skin cancer is the most common of all cancers, but it is also the most preventable.