Cervical cancer: The Pap test controversy

Do you need to have a Pap every year? The newest guidelines say no, which concerns many women. Cervical cancer survivor Jenny Charlesworth investigates.

Photo: iStock

Getting a Pap test is about as much fun as sitting through a toddler’s tantrum. But it’s the first line of defence in detecting pre- and cancerous cells of the cervix, which is why each year, Canadian women grin and bare it quite literally.

So when I learned that the Canadian Task Force on Preventive Health Care had proposed new recommendations encouraging women to start getting their Paps later (at age 25), and then only every three years, I was dumbfounded.

I’m a poster girl for the Pap. A routine yearly exam discovered a tumour on my cervix four years ago, when I was just 27. After undergoing an eight-hour surgery, I’m cancer free, but will now likely face fertility complications. Obviously, I think that getting your lady bits poked and prodded every year is well worth any discomfort. Most women I know have become accustomed to this annual ritual, but I was surprised to discover that some provinces already recommend the exam be performed less frequently.

The Pap is the most successful cancer-screening method in Canada, with an 80 percent or higher success rate in preventing mortality. (By comparison, mammography screening can reduce breast-cancer deaths by only about 20 percent.) By detecting precancerous cells early, the Pap has eliminated cervical cancer for the majority of women who would have gotten the big C.

So if it’s working to stop cervical cancer, why the new recommendations? The consensus among doctors, now armed with more understanding of the disease than ever before, is that we need to balance benefit with harm when it comes to women’s health.

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“Pap testing is a good procedure that really works, but it has been oversold to women,” says James Dickinson, the Calgary doctor who wrote the new guidelines issued by the Canadian Task Force on Preventative Health Care.

The likelihood of a Canadian woman actually getting cervical cancer in her lifetime is less than1.5 percent. This type of cancer generally develops very slowly over the course of 20 or even 30 years, so the most effective age range for screening is 30 to 69. (I somehow hit the statistical jackpot by getting this rare form of cancer in my twenties.) “By having more frequent screens, the extra reduction in cancer is calculated to be less than one percent of the already low risk, but the risk of false-positives remains about 10 percent each time,” explains Dickinson. It may be a relief to find out your Pap is a false-positive — meaning the test shows abnormal cells, which can be a precursor to cancer, when they are actually normal. But if you’ve already been sent for a follow-up, where doctors may have biopsied perfectly healthy cells (this is typically done when moderate to severe cell changes are detected; minor changes are handled with “watchful waiting” and repeat Paps). Procedures like biopsies run the risk of damaging the function of the cervix and can lead to miscarriages and premature labour down the road.

To minimize this potential harm to younger women, the Task Force proposes bumping the age at which screening begins from 20 or 21 (the age varies by province) to 25, when statistics show women still only have a two-in-a-million chance of getting cervical cancer. “There is evidence to support that younger women clear precancerous lesions much more readily than older women do,” says Gillian Bromfield, director of cancer control policy at the Canadian Cancer Society. “So in some cases, they are being sent for potentially invasive treatment for precancerous lesions that may have cleared on their own.”

Starting the screening program later might benefit a woman’s reproductive health in the long run, but the Canadian Cancer Society still recommends 21 as a more appropriate age to begin screening, so issues can be caught as early as possible. “We want to prevent cervical cancer. We want to detect it when it’s in the precancerous phase and treatment is easy, safe and effective,” says Joan Murphy, clinical lead for the Ontario Cervical Cancer Screening Program.

All of the provinces and territories oppose the age change and, since the Task Force guidelines are not mandatory, women will still be able to have Paps before they turn 25. However, many health-care providers agree that the change to screening every three years is the best measure in preventing undue harm.

Your next appointment

What does this mean for your upcoming physical? The new recommendations aren’t intended to be one-size-fits-all. Your doctor will suggest a screening schedule that’s appropriate for you, based on your personal history and family background. For example, a woman who has had abnormal Paps or has a history similar to mine can still count on her doc getting up close and personal annually. Otherwise, it may be three years before you see those stirrups. Worried that you’ll forget an appointment so far down the road? In Alberta, Saskatchewan and Ontario, programs are in place to help you keep track.

Yasmin Harrison, a general practitioner in Toronto, has been faced with mixed reactions when she tells patients they can put off their Pap. “Half of them are really happy about it, and the other half are very concerned,” she says. “Some women are still asking to have Paps yearly, despite being told it’s potentially causing more harm than good.” If a woman insists on a Pap outside of the guidelines, she may have to pay out of pocket. (The test costs about $20.) “I would have thought it would deter patients,” says Harrison. “However, the last two women who wanted Paps, even though they were unnecessary, actually offered to pay.”

The HPV connection

Human papillomavirus viruses are sexually transmitted infections that cause up to 70 percent of cervical cancer cases. Canadian health-care providers hope to introduce HPV screening in conjunction with the Pap to help identify women who are at risk for developing cancer, but are waiting for the test to become publicly funded, like the Pap.

What about the vaccine?

As more people are immunized against the HPV virus, doctors anticipate seeing less precancerous changes of the cervix in the next generation. “As good as the vaccine is — and it is very good — we still need to screen,” explains Betsy Brydon, president of the Society of Canadian Colposcopists. So far, there are no plans to abandon the Pap in favour of HPV testing across Canada, but the vaccine may impact the evolution of our cervical cancer-screening programs.