Sticking it to Cancer
A new vaccine, amazingly, may rid the world of cervical cancer, while doctors aim other needles at more killer tumors
Unfortunately, HPV is an annoyingly common germ. About 25 percent of adolescents and young women and men are infected at any given time. It's passed around through sexual contact--and that doesn't mean just fluids but also skin rubbing on skin. Fortunately, the body is pretty good at getting rid of most infections on its own. The virus infects the skin, but skin is constantly shedding cells, so it's constantly dumping the virus, too.
But sometimes it doesn't. If the virus invades skin stem cells--cells at the bottom of a skin layer that constantly divide to replenish the layers above them--it can cause a persistent infection. That can lead to trouble, but not right away. "It takes about one to three years of infection to produce a lesion," says Diane Harper, a cervical cancer specialist at Dartmouth Medical School. "And during that time you don't have any symptoms. But eventually, there will be some abnormal cells." That's a low-grade lesion, and it can hang around for an additional five years, looking more and more unusual. It's still not cancer, though. That transformation can take another five years. "So it could take 13 or so years after initial infection for a true cancer to develop," says Harper. That's why, although the peak infection years are adolescence and the early 20s, most women with actual cancer are in their 30s or older.
Katie Allen was 48 in 1995, when she began spotting blood. "I thought I was starting menopause. Cancer was the furthest thing from my mind," says the Anaheim, Calif., archaeologist. But the flow got heavier after a few months, so Allen made an appointment to see a gynecologist. She was stunned when he called to say she had cancer. "All I could think was: I have cancer, and I'm going to die. I haven't even been getting regular Pap tests. I've killed myself."
Allen opted for a hysterectomy, but during the operation surgeons found that the cancer had spread to lymph nodes in her pelvis. The surgeon took them out, but Allen still needed radiation to zap any malignant cells left behind. The radiation did the trick, but Allen suffered from side effects, such as bad diarrhea, for years. And she had exhaustive, repeated checkups every three months. "But I count myself lucky, because you die from this disease. If there was a vaccine, and my daughter could get it, I'd make her do it."
She and her daughter may be having that conversation very soon. Gardasil is designed to protect against the two most malevolent types of HPV, numbers 16 and 18. It also protects against two types that cause genital warts in men and a few hundred thousand low-grade lesions in women that prompt anxiety and thousands of pelvic exams. "That adds up to a big health expense, so removing it is a big public-health benefit," says Eliav Barr, who runs Merck's HPV clinical testing program. (These checkups and procedures cost between $3 billion and $6 billion per year in the United States.)
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