Author: Donald G. McNeail Jr. and Anahad O’Connor
The actor Michael Douglas has done for throat cancer what Rock Hudson did for AIDS and Angelina Jolie did for prophylactic mastectomy. By asserting last week that his cancer was caused by a virus transmitted during oral sex, Mr. Douglas pushed the disease onto the front pages and made millions of Americans worry about it for the first time.
In this case, it was a subset of Americans who normally worry more about being killed by cholesterol than by an S.T.D. The typical victim is a middle-aged, middle-class, married heterosexual white man who has had about six oral sex partners in his lifetime.
The virus, human papillomavirus Type 16, also causes cervical cancer. So is there any early oral screening that a man can have — an equivalent to the Pap smear, which has nearly eliminated cervical cancer as a death threat in this country?
The answer, according to cancer experts and a recent opinion from the United States Preventive Services Task Force, is no. And for surprising reasons.
The Pap test — invented in 1928 by Dr. George N. Papanicolaou — involves scraping a few cells from the cervix and checking them under a microscope for precancerous changes. Precancerous cells have a “halo” around the nucleus, while cancerous ones have larger, more colorful nuclei, said Dr. Paul D. Blumenthal, a professor of gynecology at Stanford University Medical School.
In theory, it should be similarly easy to scrape and examine throat cells. But in fact, cancer specialists said, doing so would be useless.
Virtually all cancers on the mouth, tongue, gums, hard palate or anywhere in front of the uvula (the “punching bag” dangling from the soft palate) are caused by tobacco and alcohol.
The kind of chronic HPV 16 infection that leads to oral cancer occurs much farther down, near the base of the tongue. Adding to the difficulty, the infection is often “deep down in the crypts of the tonsils,” said Dr. Eric J. Moore, a Mayo Clinic surgeon specializing in such cancers.
The tonsils, an expanse of lymphoid tissue that includes much more than the two back-of-the-throat bumps removed in tonsillectomies, have deep folds and crevices.
“If you spread them out, they’re 2 feet by 2 feet, said Dr. Marshall R. Posner, medical director for head and neck cancer at Mount Sinai Medical Center. “You can’t swab them. It’s just not possible.” By contrast, the end of the cervix swabbed during a Pap test is only about two square inches and easily reached with a speculum. It is impossible even to see deep tonsillar tissue without a scope that goes through the nose. Probing this area would set off gag and vomit reflexes so strong that patients might have to be anesthetized.
A saliva test can detect an oral HPV infection. But that’s not useful, since 85 percent of the population catches at least one of the 100 different human papillomaviruses that circulate. Most infections are beaten by the immune system in a year or two. Even among those who get an oral HPV 16 infection, less than 1 percent will go on to develop throat cancer.
“If I tell you that you have HPV in your mouth, it’s not going to help you if I don’t have anything to offer you, and you’re going to live with the anxiety and fear that you might get cancer,” said Dr. Robert I. Haddad, chief of head and neck cancer at the Dana-Farber Cancer Institute in Boston. “But if I tell a woman that she has an abnormal Pap smear, there’s something she can do about it.”
Someone with chronic HPV 16 year after year would be at the highest risk for throat cancer — but even then it is not clear what to do. Probing through all the tonsillar tissue under anesthesia looking for something worrisome to biopsy would be difficult and expensive and could set off bleeding near the entrance to the lungs.
Even when surgeons find large, cancerous lymph nodes, the primary tumor that seeded them sometimes turns out to be a speck only a sixteenth of an inch wide buried by healthy tissue, Dr. Moore said.
Although throat cancer caused by HPV is increasing, it is relatively rare. About 25,000 cases a year are diagnosed in the United States, compared with 226,000 lung cancers. But it is growing in importance as smoking-related oral cancers decline.
Oral sex has become more common since the sexual revolution of the 1960s, but not astonishingly so. According to Debby Herbenick, a director of Indiana University’s Center for Sexual Health Promotion, the mean number of lifetime oral sex partners reported by American men 35 to 54 is six. Men 55 to 64 report five, and men 25 to 34 report four. Men over 65 and under 25 report three.
However, such “fairly modest changes” in sexual habits do not explain why the cancer risk has doubled or tripled over the years, said Gypsyamber D’Souza, a viral cancer specialist at Johns Hopkins Bloomberg School of Public Health. It has risen the most in white men 45 and up. The older age is explained by the fact that, like cervical cancer, it can take decades to develop.
Men are twice as likely as women to get it, according to Dr. D’Souza, and it is more common among whites than blacks, perhaps because whites are more likely, by 90 percent to 69 percent, to have ever performed oral sex.
And straight men are more likely to get the cancer than gay men. One theory is that there may be more HPV in vaginal fluid than on the penis, said Dr. Lori J. Wirth, a head and neck cancer specialist at Massachusetts General Hospital.
The lack of a screening test means that a doctor should be seen as soon as symptoms appear: a lump in the neck, a sore throat or ear pain that persists for two weeks, or what Dr. Posner called “the hot potato voice: the way you talk when something is burning the back of your throat.”
Though no studies proving it have been done, Gardasil and Cervarix, the vaccines to prevent cervical cancer from HPV Types 16 and 18, should also prevent this oral cancer and should be offered to boys and young men, several doctors said.