By Pamela Fayerman
If you’re a female having sex, you should be getting Pap smears because various cancers, like that of the cervix, are sexually transmitted. (So are most throat cancers, which Michael Douglas had, as well as vagina/vulva, penis and anus. And, yes, women do get anus cancers).
Pap smears detect pre-cancerous changes in cells on the cervix caused by virulent, persistent strains of the human papillomavirus (HPV), the most common sexually transmitted infection. It’s so common, in fact, that almost everyone who has ever had sex will be exposed to it in the course of a lifetime. Most people clear the infection without serious ramifications.
About 150 women of all ages get cervical cancer each year in B.C. Fortunately, only a few women under the age of 25 are diagnosed with it. So the B.C. Cancer Agency is considering raising the age when women should start getting screened for cervical cancer, to 25, from the current age of 21.
In a previous post, I wrote about other guidelines that could result in up to 200,000 fewer Pap smears being done in B.C. each other, a drop of a third of all Paps conducted annually.
Nearly 600,000 Pap smears that detect pre-cancerous changes in the cervix are paid for annually in B.C. through the public health insurance plan. The age for when those tests should begin, and the frequency of such tests, is a hot-button issue as jurisdictions around the world are changing or contemplating changes to guidelines.
Some countries omit an age altogether and simply recommend that screening begin when women become sexually active.
• Few young women get invasive forms of cervical cancer each year.
• Pap smears are best at detecting cancers in women over age 35.
• HPV infections that cause precancerous lesions tend to resolve spontaneously in younger women.
• Some women end up getting unnecessary interventions like biopsies after a false positive test. Biopsies involving the removal of tissue, and subsequent scarring, may, in rare cases, lead to problems during labour and delivery.
About 60,000, or 10 per cent of Pap smears are done on women between ages 21 and 25 annually, said Dr. Dirk van Niekerk, medical leader of cervical cancer screening at the BCCA. The low incidence of cervical cancer occurring in women aged 20 to 24 may not justify screening in that age bracket, he said.
The Canadian Task Force on Preventive Health Care announced several months ago that there were no benefits outweighing potential harms of screening women younger than age 25. That provoked a sharp response from medical organizations, including the Society of Obstetricians and Gynecologists (SOGC) and the Society of Gynecologic Oncology of Canada, that screening should remain at age 21 until “better data exists to support the safety of delaying the initiation of screening ….”
Dr. Stephen Kaye, head of the B.C. Medical Association section on gynecology, said in an interview that B.C. specialists haven’t yet discussed the matter as a group. But he supports the SOGC stand.
Kaye said while there may be only a few cases of cervical cancer in B.C. each year in the youngest age group, screening may indeed be preventing many cases from ever developing into cancer. He also worries that if the age for first Pap smears is raised, young women will lose opportunities for early contact with gynecologists:
“That first point of contact is when we can also discuss contraception and screen for other infections, so we have to think about that, too.”
The matter is controversial in Britain where a rise in cervical cancer rates has coincided with a policy to delay the age to start screening. The BCMJ study says the increase in British cases is “more likely attributable to changes in sexual behaviour,” among them, more sexual partners, which is causing more HPV infections, than to a change in screening policy.
While acknowledging the argument that greater numbers of sexual partners may lead to an increase in infections and may, in fact, necessitate more screening, not less, van Niekerk said:
“That’s a difficult argument to make in favour of screening. It (screening) should stand on its own merit.”