HUMAN PAPILLOMAVIRUS AND ORAL SEX, THE CANCER CONNECTION

Human papillomavirus (HPV) infection from oral sex may have increased rate of tonsillar cancer, a study from Sweden hints.

HPV infection is considered the leading cause of cervical cancer.

Reports from both the US and Finland have documented a rise in the incidence of tonsillar cancer. This occurred in the absence of any increase in smoking or alcohol consumption, two well-known causative factors for the malignancy. This led to investigators from the Karolinska Institute in Stockholm, to look for other epidemiologic trends that might explain the growing incidence of tonsillar cancer.

HPV is known to be associated with tonsillar cancers. Whether an increase in HPV-positive cases drove the recent increase in incidence, however, was unclear.

In their study, reported in the International Journal of Cancer, the investigators found that the incidence of tonsillar cancer rose by 2.8-fold in Sweden during the study period, 1970 to 2002. Cases of the disease in women rose by 3.5-fold, while cases in men increased by 2.6-fold.

At the same time, the proportion of HPV-positive cases of tonsillar cancer increased 2.9-fold, the report indicates. In the 1970s, 23.3 percent of cases were HPV-positive compared with 68 percent in 2000 to 2002.

This may be related to patterns of sexual behavior, with high-risk HPV-16 infections, not uncommon in the genital area, also becoming more common in the mouth due to an increase in oral sex.

The investigators hypothesize that an "epidemic" of HPV infection in the oral cavity, due to changed sexual habits, "may contribute to the significant increase in incidence of tonsillar cancer."

Source: International Journal of Cancer, December 1, 2006.

GONORRHEA AND BLADDER CANCER

Gonorrhea, a common sexually transmitted infection, can double the risk of bladder cancer in men.

Earlier studies had already suggested a link and scientists from the Harvard School of Public Health in Massachusetts who monitored the health of 51,529 American men found 286 cases of bladder cancer in men who had had the infection.

"We observed a two-fold increase in bladder cancer risk among men with a history of gonorrhea," investigators said and reported in the British Journal of Cancer.

The link was stronger for invasive and advanced bladder cancer, which is more serious and difficult to treat, and among smokers.

Bladder cancer is the ninth most common cancer worldwide. Smoking is a leading cause of the disease and accounts for 65 percent of cases in men and 30 percent in women.

"Gonorrhea is an infection that often recurs, causing local inflammation and symptoms such as incomplete emptying of the bladder. The inflammation itself or the associated symptoms could be contributing to the development of bladder cancer," investigators said.

The findings strengthen the suspected linked between gonorrhea and bladder cancer in men.

The next step is to confirm whether the increased risk could be caused directly by the gonorrhea infection or its symptoms.

Source: British Journal of Cancer Tuesday, January 9, 2007






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