Genital warts tied to range of cancers
People who’ve ever had genital warts may have a somewhat higher risk of several types of cancer - possibly including common skin cancers, a new study suggests.
The findings, reported in the Journal of Infectious Diseases, confirm some well-established connections between the genital warts virus and certain cancers. And they hint that there could be additional risks.
Genital warts are caused by certain strains of the human papillomavirus (HPV). It’s well known that some of those HPV strains - some of which are the focus of vaccines - can also promote tumors.
In most people, the immune system is able to clear HPV infection fairly quickly. But some people harbor persistent infections, and a chronic infection with a cancer-linked strain can eventually lead to cancer in some cases.
HPV is probably best known as a cause of cervical cancer - a disease that experts say is nearly always caused by HPV. The virus is also blamed for most cases of anal cancer, and a large share of vaginal, vulvar and penile cancers.
Lesser known is the link between HPV and certain cancers of the mouth and throat. But a number of studies have found that a large portion of those cancers can be traced to HPV infection.
Genital warts and risk of cancer – a Danish study of nearly 50,000 patients with genital warts
Conclusions Individuals with GW have a long-term increased risk of anogenital cancers and head and neck cancers. The elevated risks of non-melanoma skin cancers might indicate an association with HPV, while excess risks of other cancers could point to differences in other risk factors between individuals with GW and the general population.
Maria Blomberg,
Soren Friis,
Christian Munk,
Andrea Bautz and
Susanne K. Kjaer
###
Published by Oxford University Press on behalf of the Infectious Diseases Society of America.
These latest findings, from a study of more than 49,000 Danish adults, confirm all those connections, said Dr. Susanne Kruger Kjaer of the Danish Cancer Society, who worked on the study.
What are Genital Warts?
Genital warts, which are also known as “venereal warts”, are a highly contagious disease that is transmitted sexually. The disease is caused by various forms of human papillomavirus (HPV). 90 percent of all cases of genital warts are caused by types 6 and 11 of HPV. Most of the people who get these two strains never develop any symptoms and visible warts. HPV may also cause cervical cancer. Around 70 percent of cervical cancer cases result from types 16 and 18. The strains, however, of HPV that bring about genital warts are not related to the ones that cause cervical cancer.
Genital warts are small cauliflower-shaped bumps that are flesh-colored. They are often as tiny as 2 millimeters in diameter, but they can grow in clusters and expand into large masses in the genital region.
They also hint that HPV might be involved in the risk of non-melanoma skin cancers - the most common, and highly curable, types of skin cancer.
CANCER IN LESS THAN FIVE PERCENT
For the study, Kjaer and her colleagues looked at medical records for nearly 33,000 women and 16,000-plus men diagnosed with genital warts over 30 years.
What is the association between HPV infection and cancer?
High-risk HPV infection accounts for approximately 5 percent of all cancers worldwide . However, most high-risk HPV infections occur without any symptoms, go away within 1 to 2 years, and do not cause cancer. These transient infections may cause cytologic abnormalities, or abnormal cell changes, that go away on their own.
Some HPV infections, however, can persist for many years. Persistent infections with high-risk HPV types can lead to more serious cytologic abnormalities or lesions that, if untreated, may progress to cancer.
As expected, they had higher-than-average rates of cervical, anal, penile and vaginal cancers, as well as certain mouth and throat cancers.