Is an HPV test better than a Pap smear for cervical cancer screening? What to know as Ontario shifts guidelines

Yahoo

27-02-2025

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Ontario is the latest province to change how it screens for cervical cancer. Starting March 3, healthcare providers will be replacing Pap smears with human paoillomavirus (HPV) testing. According to Ontario Health, HPV testing is a more accurate method for detecting cervical cancer, which means people could be tested less frequently.
Previously, B.C. and P.E.I. announced plans to adopt HPV testing as the primary method of cervical cancer screening. Quebec began a gradual transition to HPV tests in 2023 with the goal of replacing Pap smears in 2025. In July 2024, Nova Scotia announced it's intention to switch to HPV testing, but it would take approximately two years before Pap smears would be replaced.
In B.C., eligible patients can request an at-home screening kit that includes a vaginal swap which can be sent by mail to be processed. Ontarians will still need to visit a healthcare provider to receive an HPV test, since at-home tests are not part of the current roll out.
Cervical cancer is a sexually transmitted disease.Dr. Kim Alexander
In a previous interview with Yahoo Canada, Ontario-based gynecologist Dr. Kim Alexander said that roughly 95 per cent of cervical cancers are caused by HPV: "Cervical cancer is a sexually transmitted disease … so if we know your HPV status, we actually know your level of risk."
With HPV testing, she added "we can actually know whether you have the virus that causes cancer. That's super powerful." Moreover, HPV testing is essentially more accurate than Pap smears, and they can now be done faster than before.
The Canadian Medical Association Journal stated: "Pap testing has a high specificity of 96.8 per cent but a low sensitivity (55.4 per cent), which means that screening misses almost half of existing abnormalities."
A Papanicolaou test, also known as a Pap smear or Pap test, checks for abnormal cervical cells which could lead to cancer if left untreated, but they don't test for HPV itself. An HPV test, however, screens for high-risk types of HPV that could cause pre-cancers of the cervix. Neither test actually detects cancer — only abnormalities or high-risk strains of HPV.
Alexander said HPV testing comes positive on average 15 years before a cancer develops. A Pap test may never become positive — even if a person has the virus.
"The false rate of Pap test is in the range of 10 to 20 per cent, so we can miss things on the Pap test. ... HPV testing missing rate is close to zero. … It's very effective in determining your risk," Alexander noted.
Both tests are performed by taking a swab of the cervix to obtain a sample of cervical cells which are then sent for testing. Usually, these tests are tests are performed by a doctor or nurse who may insert a speculum to open the vagina to access the cervix. Some people may feel discomfort or a slight cramp during the process and may experience light bleeding afterwards, but the swab can be obtained very quickly.
Health Canada outlined HPV is one of the most common sexually transmitted infections (STIs) in the country — and worldwide. There are more than 100 types of HPV, most of which cause no symptoms and go away on their own. Some types, however, can infect areas such as the hands and feet, according to the federal agency.
"Other types target the anogenital area and are transmitted during vaginal, or oral sex or during intimate skin-to-skin contact with someone who is infected," Health Canada noted.
HPV causes almost all cervical cancers but is also linked to cancer of the throat, oral cavity, penis, anus, vagina or vulva. Moreover, it's possible to be infected by more than one type of HPV at a time, according to Health Canada. It estimated as many as 75 per cent of sexually active men and women will have at least one type of HPV infection in their lifetime.
According to Alexander, HPV testing is done in a similar way to a Pap smear, where a swab gets used to collect a small sample of cells from a cervix or vagina that may have the cancer-causing virus.
In Canada, HPV testing may not be covered by a provincial or territorial health program, and people may have to pay for it out-of-pocket.
Alexander described Ontario's current process: "If my patient gets a funny Pap test, I can actually call into the lab and ask them to run an HPV [test] on it."
"Or, I can check a box when I submit that Pap specimen that says please run HPV at this time. ... And because we really want to get a good idea about their ongoing risk, most of my patients do agree to pay the $100 that it cost to process their HPV test," she added.
Unlike the Pap test, which requires a cytopathologist to detect precancerous cervical cells, testing of a cervical sample for HPV subtypes uses polymerase chain reaction (PCR), the Canadian Medical Association Journal explained.
"One of the bonuses of implementing [HPV testing] now is that the machines we're using are the same machines that they used for COVID," Alexander explained.
"That's actually going to help speed up implementation."
Because HPV testing is able to catch problems so early, Alexander said it only needs to be done every five years, in comparison with the three years recommendation of Pap smears.
"The awesome thing about HPV testing is that it gives you a risk before you might even be developing a problem. ... Ideally, we're going to see that HPV test changed to negative for most people who get the virus," she explained.
For most people the virus is going to be a minor blip in their life.Dr. Kim Alexander
Alexander added 80 per cent of people will clear the virus from their body within two years, especially patients in their 20s: "Most people are not going to get cancer. For most people, the virus is going to be a minor blip in their life … but at some point as we get older, that gets more challenging."
Alexander said cervical cancer "is a vaccine preventable disease." The vaccine is generally available for kids in school and for people up to the age of 26, but people who are older can get it too.
The HPV vaccine commonly used is the HPV9 vaccine, also known as Gardasil 9. This vaccine protects against nine different types of HPV and protects against seven types that can cause cancers of the cervix, anus, mouth and throat, penis, vagina and vulva, and two types that can cause genital warts.
At-risk people include those who:
Have had genital warts
Have had abnormal Pap tests
Have frequent new sexual partners
The vaccine is also recommended for people who are in midlife too, aged 40 and up.
"Doctors and non-doctors have stereotypes about who's at risk, and that married people are not at risk for acquiring the HPV virus," Alexander shared.
Midlife vaccination is something to consider.Dr. Kim Alexander
"But midlife relationship instability is so common, like divorce, affairs and those who decide to have non-monogamous relationships, which can put people in midlife at risk."
Unlike younger people who have a higher chance of clearing the virus, only 60 per cent of people in their 40s clear it within two years.
"This is why midlife vaccination is something to consider ... because the virus is just there for longer, with more ability to cause problems for people," Alexander added.