British Columbia to Start Self-Testing for HPV for Cervical Cancer Screening

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Big news in cervical cancer screening: the province of British Columbia in Canada announced they are moving to at-home mail-in tests for cervical cancer screening. At first blush, it might seem like lesser care because it doesn’t require a visit to a healthcare provider for the test, but this is a step forward for cervical cancer screening. 

Let’s review

Pap Smear 101

Traditionally, cervical cancer screening or CCS involves a Pap smear. This is a scraping of cells from the cervix, and then the sample is sent to a pathology lab to be reviewed under the microscope for precancerous changes. The point of a Pap is to identify precancer early so it can be treated before it progresses to cervical cancer. 

Pap smears have been revolutionary for cancer prevention, but they are not without issues. A Pap requires a pelvic exam with a speculum because the provider needs to see the cervix, but the speculum is rated as the worst part of the pelvic exam experience. In addition, not all providers are skilled in making these exams less uncomfortable, and inexcusably, some are inattentive to the pain they are causing. Even when the exam is done by the most skilled and compassionate provider, some women find these exams painful because of medical conditions or triggering because of previous sexual or medical trauma. Like any visit to a provider, they also require time off work (I am including childcare as work), school, or require taking a child/children to the exam, all of which add a barrier. And there can even be more barriers to accessing traditional cervical cancer screening in the office. For example, transgender people with a  cervix are less likely to receive recommended cervical cancer screening versus cisgender people with a cervix, and people who live in rural communities may have difficulty accessing a provider. In addition, in Canada, many people struggle to get appointments with primary care providers as there aren’t enough. 

These aren’t the only barriers to cervical cancer screening with Pap smears. Special training is required for the lab technicians who evaluate the Pap smears. Abnormal smears are sent to a pathologist to review and give the final report, and in most labs, 10% of the normal Pap smears read by the technicians are re-read by the pathologist as quality control. A healthcare system needs enough technologists and pathologists to process Pap smears.

In British Columbia, it was taking six months (yes, you read that correctly, six months) to get the results of Pap smears, so that system was clearly not working. In addition to the anxiety, these kinds of delays increase the chances a result might never get to a patient (who may have moved, for example, during the wait), and so a precancer might go untreated. The progression from an easily treatable precancer to a more involved cancer is typically slow, so it is unlikely the six months would have resulted in precancers becoming untreatable cancers, but the risk of having paperwork lost in the shuffle increases with time. And finally, Pap smears aren't perfect. They can miss precancers and overcall abnormalities, leading to painful investigations that may not have been needed.

Suffice it to say there are many reasons to improve cervical cancer screening. 

Cervical Cancer: It’s About the Human Papilloma Virus

While there are several types of cervical cancer, the most common by far is caused by infection with the human papillomavirus or HPV. In addition, HPV-related pre-cancer is the type of cancer that is screened for with a Pap smear. The idea of detecting high-risk HPV or hrHPV, the prerequisite for cancer, makes a lot of sense.

HPV detection outperforms Pap smears in detecting precancerous lesions that need treatment and in preventing cervical cancer. If you don’t have the virus, you can’t have a precancer due to the virus. HPV testing is also automated, so it removes the human error component, and it’s highly effective because these tests are very sensitive. Also, once a lab has the equipment, they can process more HPV results over the same period compared to Pap smears. 

Some inconclusive or even false negative Pap smears are the result of collection errors. If the provider doesn’t get a good sample from the cervix, the test may not be adequate. With HPV testing, if the sample comes from the vagina, it is just as good because if there is hrHPV in the cervix, it’s also in the vagina. So, HPV testing removes the error at the level of obtaining the sample. 

We now have studies that tell us that self-collecting an HPV sample from a vaginal swab performs just as well when it is collected at home as when a healthcare provider collects it. In a study published in 2018, researchers mailed at-home HPV tests to participants, who followed up in the office and repeated the HPV test themselves, and then the provider collected the HPV test the traditional way. The prevalence of high-risk HPV was the same in all three samples. And mailing HPV tests to women who have not received their cervical cancer screening increased their rate of screening. 

It’s Not Just About HPV, It’s About HPV that Persists

In head-to-head analyses of HPV testing and Pap smears, HPV testing outperforms Pap smears. A negative HPV test is more reassuring that a precancer or cancer will not develop in the next three years versus a negative Pap smear. And this holds true at four years and even five years between HPV testing. Extending the duration between HPV testing works because it takes years for an infection to become a precancer.

You Don’t HAVE to Test At Home

With the new program in British Columbia, people aren’t required to test at home; they can still have the test done by a provider, and that’s important because it might take time for some people to be comfortable with this approach. In addition, there will be people for whom collecting an at-home test may be challenging or impossible due to physical limitations. And finally, some people might want the test done by a provider.

People can be reassured that when studies, at-home testing was well received. In one study, 96% reported being willing to do it again, 97% reported no or little physical discomfort, and 99% reported no pain. From a pain perspective, this outperforms Pap smears by a wide margin. 

Why Does HPV Screening Start at Age 25 in the British Columbia Program?

The age when screening for cervical cancer starts, and the method varies by country. Factors that influence screening programs include the health care infrastructure, local rates of cervical precancer and cancer, balancing the benefits (catching precancer) vs. the harms (false-positive tests and unnecessary procedures), and resources such as the ability of labs to process Pap smears versus HPV testing.

The Canadian Task Force on Preventive Health Care recommended increasing the age of cervical cancer screening to 25 in 2013. Beginning the mail-in screening program at age 25 is in line with these recommendations. In addition, HPV screening is not recommended for people under the age of 25 as HPV infections are so common in this age range HPV testing can lead to unnecessary follow-up procedures. In countries where cervical cancer screening starts at age 21, HPV testing is not recommended until age 25.  

Testing in British Columbia also goes until age 69.

The Three Recommended Cervical Cancer Screening Methods In the United States

Cervical cancer screening approaches are broken down by age in the United States. For individuals aged 30–65, there are three recommended approaches:

• Primary hrHPV testing every 5 years

• Pap alone every 3 years (least preferred option)

• Co-testing with a combination of Pap and hrHPV testing every 5 years

A Pap smear is recommended for people aged 21–29 years, but hrHPV alone is an acceptable alternative for those aged 25–29 years. The reason a Pap is preferred for ages 25-29 is that hrHPV testing by itself at this age increases the number of procedures that are needed (colposcopies) without further reducing the rate of cervical cancer.

Primary Prevention

Cervical cancer screening, whether HPV testing or Pap, is secondary prevention. Primary prevention is getting the HPV vaccine. And getting vaccinated against HPV is highly effective. For example, in the UK, vaccination of girls at ages 12-13 resulted in an 87% reduction in cervical cancer and a 97% reduction in precancer compared to age-matched unvaccinated controls, and in Sweden, vaccination before age 17 resulted in an 88% lower rate of cervical cancer versus those who were not vaccinated. 

Guidelines May Change Down the Road…And That’s Okay

Cervical cancer screening guidelines are periodically updated, and that’s okay. New studies are done, and new tests may be developed. We want science to change with new data. It can be hard to switch from something that we’ve always done; for example, a lot of people were worried when we switched from annual Pap smears to every three years because how could less screening be better? But an annual Pap doesn’t detect more cancers; what it does is find more abnormalities that aren’t cancer, leading to more unnecessary and painful tests as well as worry. 

We Need to Meet People Where They Are While Also Considering the Limits of the Health Care System

I think the BC program is a great example of this. We know HPV testing is where cervical cancer screening is headed; a six-month delay in getting Pap results is unacceptable, and getting access to a doctor to do a Pap smear can be challenging in many communities. Mail-in-home HPV testing is a solution for cervical cancer screening that provides people with the best test and has the potential to improve access and convenience. As more and more regions and countries adopt this approach, we will get more data about how these programs are received and their impact on cervical cancer.

References

BC Gov News https://news.gov.bc.ca/releases/2024HLTH0001-000015

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