Despite the active campaign on cancer prevention, the incidence of throat cancers in the United States has not dropped in recent years. In fact, the statistics are even rising in some areas, as opposed to the downward trend in other head and neck cancers that are usually associated with smoking and drinking alcohol.
It is being investigated if infections with the sexually transmitted human papilloma virus (HPV) could be the real cause. HPV is a virus that causes infections such as genital warts and most cervical cancers. Recently, researchers have found that the transmission of HPV through oral sex is a potential cause of throat cancer.
Early findings emphasize the importance of research directed at establishing if the newly available HPV vaccine is effective in males. This vaccine is considered to be almost 100% effective in preventing cervical infections. Thus, the medical community and vaccine industry is encouraged to study its role in preventing oral cancer.
At present, tobacco use and drinking alcohol are ranked as the biggest risk factors for head and neck cancers. According to the American Cancer Society, about 90% of patients with these sickness either smoke or chew tobacco, or have done so in the past, and up to 80% of oral cancer patients also drink a lot of alcohol.
The newly published analysis of head and neck cancer trends in the U.S. showed that the decline in smoking has led to a decline in most head and neck cancers over the past two decades. However, throat cancer remains to be the main exception to this trend. This is more specifically defined as cancer of the oropharynx, which includes the tonsils, base of the tongue and soft palate, and side and back of the throat.
Although these cancers are rare, their incidence has remained steady, overall, while tongue cancer rates among young adults have increased. They conclude that this is likely due to HPV infections, which could be spread through oral sex.
Over the last five years, 35% of the throat cancer patients treated at M.D. Anderson Cancer Center had no history of smoking and that close to 90% of patients who had never smoked showed evidence of oral infections with HPV.
The current policy in the U.S. is to recommend HPV vaccine only to young girls aged 11 to 12 years old, and for women up to age 26 who have not received it yet. Researchers concluded that vaccinating only females against HPV could result in a missed opportunity to prevent throat cancers. However, in countries like Australia and Mexico, the HPV vaccine is being offered even to males, though there is still no clinical proof to show that HPV infections in men lead to throat cancer. Studies are now under way to find out if the vaccine can protect boys against genital HPV infections.
“The HPV vaccine could be a very effective protection against cervical cancer, and there is a good chance that it will reduce the incidence of other types of HPV-promoted cancers as well,” said Debbie Saslow, PhD, of the American Cancer Society. “But we have no data to confirm that, and we won’t have any in the near future.”