The U.S. has arguably the world’s best medical tools available — especially when it comes to cancer screening, which has significantly reduced the mortality rates of serious killers such as breast and colorectal cancer in the last few years. But too much of a good thing can be bad, and expensive.
A government study finds that too many doctors are using the wrong test or testing the wrong women for the human papillomavirus, or HPV, the virus that causes cervical cancer. The unnecessary tests are costly and may be leading to harm and anxiety in women who receive extra medical care they don’t need.
The study, led by Dr. Mona Saraiya of the Centers for Disease Control and Prevention (CDC), suggests that doctors are still confused about when to use the two main cervical cancer screening tools — the Pap smear and the HPV DNA test — and in which women.
The two screens are not interchangeable. The Pap smear checks the cervix for abnormal or precancerous cells; because cervical cancer is slow growing, the Pap smear is usually sufficient for catching and treating it or removing potentially cancerous cells early on.
The newer HPV test adds to the information gleaned from the Pap. Now that doctors know that most cervical cancer cases are caused by certain strains of HPV, they can test abnormal cells in the cervix for those strains to determine whether a woman is at higher or lower risk of developing cancer.
Guidelines from the American College of Obstetricians and Gynecologists (ACOG) recommend that Pap and HPV tests be used simultaneously in women 30 and older. But Saraiya’s study found that many doctors are using the tests in younger women. The AP’s Lauran Neergard reported:
Why the age limit? [The American Cancer Society's gynecologic cancer director Debbie] Saslow says HPV is nearly as common as the common cold, especially in younger women — but their bodies usually clear the infection on their own and only a years-long infection is risky. Learning that a 20-something has HPV increases the odds of more invasive testing that in turn can leave her cervix less able to handle pregnancy later in life. Younger women are supposed to get HPV testing only if a Pap signals a possible problem and doctors really need the extra information.
Saraiya found that 60% of doctors and clinics give a routine Pap-plus-HPV test to younger women. She also found that 28% of doctors are performing an unnecessary type of HPV test on women of all ages: one that detects low-risk strains of the virus that can cause genital warts, but not cancer. This test came before scientists understood the risks of the various HPV strains, and some doctors still test for both the high-risk and low-risk strains, perhaps not realizing there’s a difference or because order forms for lab tests don’t differentiate between the two. However, the older HPV test is unnecessary because its results do not change women’s care.
The study suggests that women would be wise to educate themselves about how much cancer screening they really need. If you’re unsure, take a look at these guidelines from ACOG. Neergard summarized them clearly:
—Routine Paps start at age 21.
—Most women in their 20s get a Pap every two years
—Women 30 and older wait three years between screenings if they’ve had a negative Pap and negative HPV test, or three consecutive clear Paps
—If a Pap is inconclusive at any age, HPV testing may help rule out who needs further examination and who can just repeat a Pap in a year
—Anyone who’s been vaccinated against HPV, a relatively new vaccine, still must follow Pap screening guidelines for their age group
—Higher-risk women, such as those with HIV or previous cervical abnormalities, need more frequent screening
Also be sure to download the CDC’s 25-page booklet [PDF], which explains everything you need to know about cervical cancer screening.
Saraiya’s study was published in the journal Obstetrics & Gynecology.