Human Papillomavirus (HPV), a group of viruses commonly linked to the sexually transmitted disease known as genital HPV infection, has long been associated with the development of certain types of cancers - specifically cervical cancer. However, in some cases, HPV can lead to a type of skin cancer known as squamous cell carcinoma.
While squamous cell carcinoma has a 95 percent five-year cure rate when detected and treated early, genital skin cancers can be difficult to diagnose since they are not always readily visible and may not exhibit any noticeable symptoms. As studies show, this can lead to a fatal outcome.
Speaking today at the 65th Annual Meeting of the American Academy of Dermatology, dermatologist Martin A. Weinstock, MD, PhD, FAAD, professor of dermatology and community health at Brown University in Providence, RI, and chief dermatologist at Veterans Affairs Medical Center in Providence, presented key findings from a population-based study of nonmelanoma skin cancer mortality in the United States from 1969 to 2000. The data shows a large number of fatal nonmelanoma skin cancers that occurred in the genitalia of men and women age 65 and older, which may have been caused by HPV.
Skin cancers are divided into one of two classes - nonmelanoma and melanoma. Nonmelanoma skin cancers (NMSCs) are the most common forms of skin cancer, which include basal cell carcinoma and squamous cell carcinoma. While basal cell carcinomas rarely spread to other parts of the body, squamous cell carcinomas can spread to other organs if not treated early. Melanoma can rapidly spread to the lymph system and internal organs, making it the most serious and deadly form of skin cancer.
Dr. Weinstock and his colleague Kevan G. Lewis, MD, a resident in the department of dermatology at Brown University, reviewed records from the U.S. National Center for Health Statistics and the Centers for Disease Control and Prevention mortality database. They found that of the 74,000 deaths that occurred over a 32-year period from NMSCs, genital NMSCs claimed the lives of nearly 30,000 men and women. Of the nearly 30,000 deaths attributed to genital NMSC, women were three times more likely to die of this type of cancer than men - with 22,000 deaths occurring in women compared to 8,000 deaths in men.
"As dermatologists, we expect to see skin cancers induced by ultraviolet light, because sunlight is one of the primary risk factors for the disease," said Dr. Weinstock. "But some of the most dangerous types of skin cancers are those that are not sun-induced, such as skin cancers that occur on genital skin - a place that is not exposed to intense sun and is not routinely examined by dermatologists. That's why there needs to be an increased awareness of this issue, so patients and physicians can be better prepared to detect these cancers early before they become fatal."
Dr. Weinstock reports that the number of deaths from genital NMSCs increased with age, when mortality rates were age-adjusted to the 2000 U.S. standard population based on the number of deaths per 100,000 people per year. Specifically, the number of women under age 65 who died of genital NMSCs were less than one death per 100,000 people per year. For a city of 1 million people, one death per 100,000 means that 10 people die per year.
For women between the ages of 65-74, 1.8 deaths per 100,000 people per year were reported; for women between the ages of 75-84, the number rose to 4.1 deaths per 100,000 people per year; and for women age 85 and older, the number jumped to 8.8 deaths per 100,000 people per year.
For men under age 65, less than 0.5 deaths per 100,000 people per year were reported; for men between the ages of 65-74, 1.0 death per 100,000 people per year was reported; for men between the ages of 75-84, the number rose to 1.9 deaths per 100,000 people per year; and for men age 85 and older, the number jumped to 4.1 deaths per 100,000 people per year.
"The number of deaths attributed to genital NMSCs was higher than expected, and we believe HPV was the major cause of these cancers," noted Dr. Weinstock. "The availability of the new HPV vaccine offers the potential for a substantial reduction in the development of these skin cancers for future generations.
Since HPV is a sexually transmitted disease, both men and women can practice preventive measures that could lead to a decline in mortality rates from genital NMSCs, and heed the warning signs of the disease - including new growths or sores that don't heal - to detect it early."
When the death rates from non-genital NMSCs were examined, Dr. Weinstock found that men were twice as likely as women to die from these typically sun-induced skin cancers that commonly occurred on the face, head or neck. Specifically, approximately 45,000 deaths were attributed to non-genital NMSC - roughly 27,000 deaths in men and 18,000 deaths in women.
Similar to the mortality rates for genital NMSCs, the number of deaths from non-genital NMSC also increased sharply with age for both genders. Overall, the combined number of men and women under age 65 who died from non-genital NMSC was less than one death per 100,000 people per year; for adults between the ages of 65-74, 1.9 deaths per 100,000 people per year was reported; for adults between the ages of 75-84, the number rose to 4.4 deaths per 100,000 people per year; and for adults age 85 and older, the number increased dramatically to 11.9 deaths per 100,000 people per year.
"The one bit of good news from our study is that overall the death rates from genital and non-genital nonmelanoma skin cancers have been declining over the years," added Dr. Weinstock. "Even as the number of older adults increase each year, we are finding that the overall death rates are decreasing - which could be attributed to a greater early detection and prevention of skin cancer. We are hopeful that this trend will continue and expect that the HPV vaccine will play a pivotal role in reducing the overall death rate of genital skin cancers in the future."