Twelve to 15 million white patients living in the United States have had at least one nonmelanoma skin cancer in their lifetimes, according to estimates based on a new mathematical model.
This figure is approximately twice that of previous estimates based on patient surveys, such as the estimate calculated in the National Health Interview Study, according to Dr. Robert S. Stern of Beth Israel Deaconess Medical Center and Harvard Medical School, Boston.
This difference can be attributed in part to people often incorrectly reporting their skin cancer histories when they are surveyed, falsely believing that basal cell and squamous cell lesions are not cancerous or that all skin cancers can be considered melanoma.
Dr. Stern devised his mathematical model using the same basic data available from national samples, such as the Surveillance, Epidemiology, and End Results (SEER) studies and information from the National Cancer Institute.
His model, however, took into consideration several factors that had not been accounted for in previous estimates, such as the likelihood that patients develop numerous nonmelanoma skin cancers over the course of several years and that “a substantial proportion” of patients with melanoma also have nonmalignant skin cancers.
According to his model, “about 13 million white non-Hispanic U.S. residents (6%) have had more than 22 million nonmelanoma skin cancers” (Arch. Dermatol. 2010;146:279-82).
These estimates put the prevalence of a skin cancer history at a level far higher than that of any other cancer—prevalence that “exceeds that of all other cancers diagnosed since 1975,” he added. “Recent population-based data concerning skin cancer incidence, morbidity, and cost of care are lacking for the most common types of skin cancer, [basal cell carcinoma] and [squamous cell carcinoma].”
Regarding patients' inaccurate reporting of skin cancer histories in surveys and interviews, Dr. Stern noted that many patients equate skin cancer with melanoma. “Hundreds of thousands of patients may be unnecessarily burdened with the belief that they have had a potentially lethal cancer (melanoma) when in fact they have had a skin tumor that is very unlikely to be lethal,” he wrote.
In contrast, patients with breast or prostate cancer are much more likely to accurately report their cancer histories, so incidence and prevalence estimates for these tumors are much more accurate than those for skin cancer, Dr. Stern noted.
This study was funded in part by the National Institutes of Health. Dr. Stern reported being a consultant for Johnson & Johnson, Vertex, and Takeda and an expert witness for Alphapharm, Mutual Pharm, and Johnson & Johnson.