Cervical Cancer and HPV
By Bridget Avila
You would think from the commercials that we’d just discovered the link between cervical cancer and human papilloma virus (HPV). Physicians have known for decades that certain strains of HPV (the virus that causes genital warts and other subtler symptoms) caused changes in cells that could lead to cancer. In large part this is why women age 21–30 (and younger women who have been sexually active for 3 or more years) are advised to get annual Pap smears and women over 30 are advised to have Pap smears regularly. The test acts as a screening for abnormal cells caused by HPV that might be precancerous.
But all of a sudden this last year we’ve had shiny-faced women of all ages speak to us earnestly from the television and tell us that they (or their daughters, granddaughters, nieces, or friends) can be “one less,” meaning one less woman to develop cervical cancer. It was the market debut of a vaccine against certain strains of HPV and it’s led to some interesting conversations about education about sexually transmitted diseases, state-required immunizations, and whether the vaccine should be recommended not only for girls and women but also for boys and men.
Cervical Cancer 101
The cervix is the part of a woman’s anatomy that connects the body of her uterus, or womb, to her vagina, or birth canal. Cervical cancer begins on the surface of the lining of the cervix and develops gradually. Cells in this lining can develop several different precancerous changes that can be discovered in a Pap smear. These are named depending on which types of cells have been changed and how.
The American Cancer Society estimates that in 2007 about 11,150 cases of invasive cervical cancer will be diagnosed in the United States and the disease will kill about 3,670 women nationwide. Worldwide, cervical cancer strikes nearly half a million women each year and kills a quarter of a million women. Once cervical cancer was one of the most common causes of cancer death for American women, but the death rate among those with the disease declined by 74 percent between 1955 and 1992, mainly due to the increased use of the Pap test.
Like many diseases, cervical cancer affects women of color disproportionately to white women. Cervical cancer hits Hispanic women hardest, at a rate that is twice that of non-Hispanic white women, and African American women develop this cancer about 50 percent more often than non-Hispanic white women. A historical lack of access to preventive health care may cause such disparities. Because of this, some public health advocates have charged that opposing use of an HPV vaccine is racism.
Left untreated cervical cancer can cause an agonizing death marked by hemorrhaging of the womb or bursting intestines. A cervical cancer diagnosis is hardly a death sentence, though. When the disease is treated (with surgery, radiation, or chemotherapy, depending on the stage of the cancer), the 5-year relative survival rate for the earliest stage of invasive cervical cancer is 92 percent; for all stages combined the overall 5-year survival rate for cervical cancer is about 72 percent.
Pap Smears: Who and How Often?
In general it’s recommended that women age 21–65 (or younger if sexually active) receive routine Pap smears and pelvic exams. Frequency of these tests varies by age and health history. Women should consult with their health care providers to decide when testing is appropriate. The American College of Obstetricians and Gynecologists recommends the following:
· If you are younger than 30 years old you should get a Pap test every year.
· If you are age 30 or older and have had normal Pap tests for 3 years in a row, talk to your doctor about spreading out Pap tests to every 2 or 3 years.
· If you are age 65 to 70 and have had at least three normal Pap tests and had no abnormal Pap tests in the last 10 years, ask your doctor if you can stop having Pap tests.
The only women who do not need regular Pap tests are:
· Women over age 65 who have had a number of normal Pap tests and have been told by their doctors that they don’t need to be tested anymore.
· Women who do not have a cervix and are at low risk for cervical cancer. These women should speak to their doctors before stopping regular Pap tests.
Some research has indicated that as women age they are more likely to have falsely positive readings of their Pap smears. Because this can cause stress and unnecessary medical procedures, health care providers are urged to be cautious in using Pap smears in women over age 65.
Causes and Risk Factors
On a basic level, cancer occurs when a change occurs in cells, causing them to grow and divide at too fast a rate, forming a tumor or tumors. Your genetic makeup can influence how your body responds to certain environmental factors that may induce cells to turn into tumor factories. Scientists now believe that two proteins produced by particular strains of HPV turn off some genes that suppress tumors. This could lead to uncontrolled growth of the cervical lining cells and, eventually, cancer.
However, this does not completely explain how cervical cancer is caused. While HPV can cause cervical cancers, women may have HPV and never develop cervical cancer. Other risk factors are strongly correlated with cervical cancer:
· Smoking
· Immune system deficiency
· Chlamydia
· Eating a diet low in fruits and vegetables and being overweight
· Long-term use of oral contraceptives (Discuss with your doctor whether the benefits of oral contraceptives outweigh this potential risk.)
· Many full-term pregnancies
· Low socioeconomic status
· Having a mother who took diethylstilbestrol (DES) when pregnant
· A family history of cervical cancer
HPV—A Virus with No Cure . . .
Above all, however, the most important risk factor for cervical cancer is HPV infection. HPVs belong to the family of viruses called papillomaviruses because some of them cause warts or papillomas (noncancerous or benign tumors). However, the strains of HPV that cause raised bumpy warts in the genital area are seldom linked to cervical cancer and are considered “low-risk.”
There is no cure or treatment for HPV infection, which many people will have in their lifetimes, and an HPV infection does not necessarily lead to cancer. Usually a person’s immune system is successful in fighting the virus. If a woman’s Pap test results indicate changes that may have been caused by HPV, further tests are performed. Doctors have at their disposal a variety of tests to determine whether HPV is indeed present, and if so, which strains, as well as biopsies to determine whether the abnormal tissue is cancerous or not.
Statistics on the Ubiquitous HPV:
· Approximately 20 million Americans are currently infected with HPV.
· At least 50 percent of sexually active men and women acquire genital HPV infection at some point in their lives.
· By age 50 at least 80 percent of women will have acquired genital HPV infection.
· About 6.2 million Americans get a new genital HPV infection each year.
Source: the Centers for Disease Control and Prevention . . . But Now There’s a Vaccine
After 70 years of trial and error researchers have recently finalized two vaccines against HPV. Gardasil (from pharmaceutical manufacturer Merck) and Cervarix (from pharmaceutical manufacturer GlaxoSmithKline) protect against HPV types 16 and 18 (the two types that cause most cervical cancers) and Gardasil prevents genital warts caused by HPV types 6 and 11 (the types that commonly cause warts). While Gardasil is already on the market, at press time Cervarix had not yet received FDA approval, but was expected to be on the U.S. market in 2008. It has already been approved in the European Union.
Gardasil may have a jump on competition with Cervarix since it reached the market first, but GlaxoSmithKline has already launched clinical trials comparing the efficacy of the two vaccines.
Both vaccines are administered in a series of three injections over a 6-month period. Gardasil should be covered by most medical insurance plans and by government programs that pay for vaccinations in children under 18. You may want to check with your insurance company before you or your daughter gets the vaccine series, which costs around $360 before doctor’s fees.
The Federal Advisory Committee on Immunization Practices and the American Cancer Society (whose recommendations focus on the currently approved Gardasil) recommend that the HPV vaccine be administered routinely to females age 11–12 and as early as age 9, at the discretion of doctors. The vaccine is most effective if administered before the onset of sexual activity. “Catch-up” vaccines are recommended for girls age 13–18, but since women age 19–26 are more likely to be sexually active, recommendations vary as to whether these women should receive the vaccine. Women in this age group should discuss the benefits of the vaccine with their health care providers.
Studies have shown Gardasil to be 89 percent effective in preventing infection with the viral strains it protects against and 100 percent effective in preventing cervical cancer, precancerous lesions, or genital warts.
So What’s the Fuss?
Several aspects of the marketing of this vaccine have sparked controversy. There has been a push for states to rapidly mandate vaccination for girls age 11 or 12 before they can be admitted to school. Some parents felt a mandate was tantamount to the state’s usurping parental control over a child’s health care. Social conservatives spoke out against a bill introduced in the Maryland senate that would have mandated the vaccine, claiming that administering the vaccine would promote promiscuity. Tony Perkins, president of the Family Research Council, has said that he would refuse to inoculate his own daughter. “Our concern is that this vaccine will be marketed to a segment of the population that should be getting a message about abstinence. It sends the wrong message.”
Such arguments dismay physicians and public health advocates who worry that promoting abstinence alone will leave women vulnerable to a deadly disease that could be prevented. Others point out that there’s no evidence to support the argument that protection against one STD would lead to sexual activity. Alan M. Kaye, executive director of the National Cervical Cancer Coalition, compares inoculation to wearing a seatbelt: “Just because you wear a seatbelt doesn’t mean you’re seeking out an accident.”
Supporters point out that the Maryland bill provided an opt-out clause for parents who object to the vaccine for religious reasons. And if the vaccine is mandated it will not be the state’s first mandatory vaccine against a sexually transmitted disease. Just in 2006 the vaccine for hepatitis B (which is transmitted by sexual contact and sharing of hypodermic needles associated with intravenous drug abuse) was added to the state’s list of mandatory inoculations.
Other critics have objected to the mandates for different reasons. The American Academy of Family Physicians’ policy statement reads, “The AAFP feels it is premature to consider school entry mandates for human papillomavirus virus (HPV) vaccine until such time as the long term safety with widespread use, stability of supply, and economic issues have been clarified.” Some question how long the vaccine remains effective and whether vaccinating at an early age can lead to a mistaken belief that a woman is protected when she no longer is. Similarly, some charge that the way the vaccine has been marketed leaves women believing they no longer need the Pap tests that provide life-saving early detection of precancerous cell changes. At $360 per patient for the vaccines alone, before any charges for administering them, the cost could keep some children out of school. And critics of the manufacturer of the only vaccine approved so far charge that it pressed for rapid adoption of mandatory vaccination during the period when it was the only source of HPV vaccine.
Maryland’s original HPV vaccine legislation got nowhere and was replaced by a more cautious bill calling for a study of the issue by legislators, teachers, and health professionals through 2008. Besides arguments from opponents to a mandated vaccine, there are also the historical and logistical hurdles. Last January thousands of students were kept out of state schools for weeks because they had not received recently mandated chickenpox and hepatitis B vaccines, despite publicity and free clinics. Additionally, mandated inoculations need funding—something that can be hard to come by in the budget of a state that’s already struggling against a deficit.
In the long run we are likely to see more of the HPV vaccines rather than less of them. As HPV is thought to cause other cancers in both men and women, clinical trials are currently under way to test the vaccines’ efficacy in boys and men. Eventually that may mean HPV vaccines required for all students.
While finding a panacea for cancer may still be a pipe dream for budding medical researchers, HPV vaccines raise the hope that cervical cancer may go the way of smallpox and other diseases eradicated by vaccination. And since HPV affects both women and men and is the likely culprit in cancers impacting both sexes, the topic of the HPV vaccine is one that no one should ignore.
Bridget Avila is a freelance writer living on the Broadneck Peninsula who has worked in clinical health care settings and on studies impacting medical research policy.