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Vaccinations key to reducing HPV’s deadly strands

Howard Manly | , Karen Miller | 8/5/2013, 6 a.m.
HPV is the most common sexually transmitted infection in this country

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Ursula A. Matulonis, M.D. Medical Director, Gynecologic Oncology Dana-Farber Cancer Institute

Much progress has been made on the war on cancer. The Journal of the National Cancer Institute recently reported that death rates from all cancers combined are on the decline and improvements were evident in both men and women in all races and ethnicities. Yet, the 2012 report confirmed that the incidences of some HPV-related cancers are on the rise.

HPV, or human papillomavirus, is the most common sexually transmitted infection in the country. The Centers for Disease Control and Prevention (CDC) estimates that at any given time, roughly 20 million people are infected with HPV and another 6 million join the ranks each year.

It’s no wonder. There are more than 40 types of HPV that infect the genital areas of both males and females. Yet, most people remain unaware of these potentially lethal germs. Typically, HPV doesn’t have any symptoms, and its low-risk as well as high-risk strands are usually eradicated by antibodies found in healthy human immune systems.

But some high-risk HPVs, such as HPV 16 and HPV 18, can linger within a body and cause a myriad of cancers. Those two HPV strands account for 70 percent of cervical cancers but can be found in 40 percent of other genital cancers and almost all anal cancers. HPV 16 alone accounts for more than 50 percent of oral cancers.

The cause of the rise in HPV-linked cancers is not completely clear, but changes in sexual behavior have clearly played a part. According to the most recent Youth Risk Behavior Surveillance System, a survey conducted by the CDC, almost half of all U.S. high school students surveyed in 2011 said that they had had sexual intercourse, and more than 15 percent of these teens admitted to having sex with four or more people in their short lifetime.

The earlier in life sexual intercourse is started and the greater the number of sex partners, the greater the probability of infection and the greater the probability of a cancer-causing HPV strain.

Not surprisingly, smoking also plays a role and the combination of the two — smoking and HPV — packs a more dangerous wallop. Smokers who are afflicted with HPV 16 and HPV 18 are at increased risk for genital and oral cancers.

So significant is the impact of HPV in cervical cancer that in 2012, the American Congress of Obstetricians and Gynecologists coupled HPV testing with Pap smears for women 30 to 65 years old as part of screening for cervical cancer. The objective is to identify high-risk HPV before it can do permanent damage.

Cervical cancer is more common in Latinas and blacks, but black women die of it at a greater rate than any other race. Although its incidence and death rates have plummeted since the inception of Pap smears, the American Cancer Society estimates that in 2013, more than 12,000 women will be afflicted with the disease and roughly 4,000 women will die.

It can take up to 20 years for the cancer to form, but it leaves tell-tale signs before it strikes. Fortunately, these differences are detectable under a microscope, which allows treatment for pre-cancerous lesions in the cervix. “The cells look different,” explained Dr. Ursula A. Matulonis, the medical director of Gynecologic Oncology at Dana-Farber Cancer Institute. “They lose their features of what a normal cell should look like.”