STD Awareness: HPV Testing vs. the Pap Test

I love writing about health and medicine, but I hate going to the doctor. I don’t like taking my clothes off for a dermatological exam, I don’t like rolling my sleeve up for a shot, and I don’t like opening my mouth for a dentist. I don’t even like having my blood pressure taken — it gives me the heebie-jeebies, and probably a case of white-coat hypertension too.

For now, pelvic exams are a mainstay — and an important part of cancer prevention.

So when it comes to something even more invasive, like the Pap test to screen for cervical cancer, I’m one of those people pining for a magic wand — a tool that a health care provider can wave over your fully clothed body to detect disease. The Pap test may have transformed a scourge like cervical cancer into one of the most easily detected and treated cancers — and for that I love it — but I still fervently wish for its demise. As long as it’s replaced by something better, of course.

Last month, an article in JAMA inspired a burst of headlines. “HPV test more effective than Pap smear in cancer screening,” said CNN. Or as WebMD put it more succinctly, “HPV Test Beats Pap.” Then, last week, the U.S. Preventive Services Task Force updated their guidelines to recommend that patients 30 and older can forgo the Pap test in favor of HPV testing alone. This news might be welcome to anyone who dislikes regular Pap tests and wishes to avoid stirrups and speculums. Unfortunately, HPV tests aren’t the noninvasive “magic wand” so many of us hope for. From the patient’s perspective, the experience of undergoing an HPV test is no different from the experience of undergoing a Pap test. They both require a pelvic exam — the stuff of stirrups and speculums.

Cancerous cervical cells, as seen under a microscope. Image: National Cancer Institute

cancerous cervical cells

During a pelvic exam, a health care provider may take cell samples from your cervix. At that point, you’re all done, but for the cell samples, the journey has just begun. Once in the lab, a technician performs tests on those samples — a Pap test, an HPV test, or both. The Pap test involves examining cervical cells under a microscope for the telltale signs of cancer progression. Cervical cells start looking weird even when in a “precancerous” stage, meaning that doctors can treat cervical abnormalities before they have the chance to develop into cancer. The HPV test, on the other hand, doesn’t use a microscope at all. This test analyzes cervical cells for human papillomavirus DNA — evidence of infection with HPV, the virus that causes virtually all cervical cancers. A persistent HPV infection is what causes cervical cells to look weird under a microscope in the first place, but an HPV test can catch these infections earlier.

Current guidelines are for patients in their 20s to receive Pap tests every three years, as long as the results are normal and additional tests aren’t required. Because HPV infections are so common, it’s considered more prudent to use a microscope to check for cellular abnormalities in this age group, as an HPV test alone would lead to too many false-positive results — false alarms that subject patients to anxiety and unnecessary follow-up testing.

Once patients reach their 30s, however, they have the option to continue receiving a Pap test every three years, or to receive an HPV test every five years — dispensing with the Pap test altogether. (They can also opt to receive a Pap and HPV “co-test” every five years.) In these older patients, HPV infections are less common, meaning that false positives will also be less common. HPV testing seems to be accurate on its own, and many researchers are concerned that throwing Pap tests on top of HPV tests only increases the risk of false-positive results.

Further analysis by the USPSTF found that HPV testing after the age of 30 is associated with significantly lower cervical cancer mortality rates. For every 1,000 women, there are:

  • 8.34 deaths among those who receive no cervical cancer screening
  • 0.76 deaths among those who continue to receive the Pap test alone every 3 years
  • 0.30 deaths among those who receive Pap and HPV co-testing every 5 years
  • 0.29 deaths among those who receive HPV testing alone every 5 years

The HPV test alone can be used to screen for cervical cancer in patients 30 years of age and older — and does not need to be paired with a Pap test. Under this model, cervical cells are first tested for HPV, and are only subjected to further inspection under a microscope if they test positive for the virus. Last month’s JAMA study found this method is more accurate and detects precancer earlier. Skipping the Pap test also has the added benefit of saving time and money by avoiding unnecessary additional testing.

It would be nice if “skipping the Pap test” meant skipping the stirrups and speculum, but, for now, cervical cancer screening requires taking cell samples from the cervix. In some countries, HPV testing can be performed on samples of vaginal or cervical secretions that patients or clinicians can collect with a swab — which is less invasive than taking samples from the cervix — but in the United States, patients don’t currently have this option.

The adoption of the HPV test as a replacement of — or a complement to — the Pap test gives patients beyond their 20s more accurate results and the ability to wait longer between screening tests, while still enabling doctors to treat cervical precancer in its earlier stages. Additionally, as more tweens and teens are vaccinated against HPV, infection rates will decline, setting the stage for healthier cervixes across the population. Someday, maybe we’ll even get that magic wand, but for now, thanks to HPV testing and vaccination, we’re already poised for fewer invasive tests and less cervical cancer.

An estimated 9 out of 10 cervical cancers could be prevented with high HPV vaccination rates and widespread use of cervical cancer screening — services offered by Planned Parenthood health centers. Gardasil 9 protects against the seven strains of HPV responsible for 90 percent of cervical cancers, and Pap testing and HPV testing screen for cervical cancer. Planned Parenthood Arizona does not currently offer HPV testing without an accompanying Pap test — but we follow USPSTF guidelines and are evaluating how to update our services.

Click here to check out other installments of our monthly STD Awareness series!