Dr. Marla Shapiro: New cervical cancer guidelines
Dr. Marla Shapiro, Canada AM health and medical expert
Published Tuesday, January 8, 2013 7:12AM EST
Last Updated Tuesday, January 8, 2013 8:23AM EST
New guidelines have been released in Canada that recommend less frequent routine screening for cervical cancer. When we hear that we should be doing less, many women worry that it is financially driven and not in their best interest, but data worldwide does show that in most cases we are doing Pap tests too frequently.
So what do the guidelines say?
Firstly, the age of initiation of screening has changed. The reason is that we now understand the link between the human papillomavirus and its causative effect in causing cervical cancer. It is why there is such a push for young women -- before the age of any sexual activity -- to have the HPV vaccine. We also know that women under the age of 30 when exposed to HPV will clear the virus on their own as long as they have a healthy immune system. The virus has to persist in your body to cause disease. For that reason, the age of screening has been pushed back. Screening should begin at age 25 and be conducted every 3 years.
In addition, the guidelines also recommend screening for women aged 70 years and older who have not been adequately screened in the past. However, if there has been adequate screening -- meaning 3 normal Paps in the past 10 years -- screening can end at age 70.
Rates of cervical cancer and deaths from the disease have decreased significantly over the past 30 years since the introduction of the Pap test, the main screening tool. It detects precursor lesions and can lead to early treatment and better long-term outcomes for women compared with treating the disease once symptoms arise. It is likely that much of the change seen in the incidence of cervical cancer in Canada is due to screening.
The key message here is that early and frequent (often annual) cervical screening is unnecessary: other countries have achieved similar outcomes with less frequent testing and starting screening at older ages.
This represents an update to the Canadian Task Force on Preventive Health Care's guidelines issued in 1994. Aimed at physicians and policy-makers, the guidelines contain recommendations for cervical screening based on the latest available evidence as well as comparisons with screening in other countries.
- No routine screening for women under age 25, including sexually active wome
- Routine screening every 3 years for women aged 25 to 69 years
- Ending screening for women aged 70 and over who have undergone adequate screening - that is, 3 successive negative Pap test results over the previous 10 years
- Screening for women over age 69 if they have not undergone adequate screening - that is, until 3 negative test results have been obtained.
- Screening frequency should be appropriate for the risk profiles of women
- Women who have had complete hysterectomies for benign issues will not need further screening
- Women who have sex with women should be screened according to the above recommendations.
- Most countries outside North America recommend 3- or 5-year intervals for cervical cancer screening
- U.S. task force recommends human papilloma virus (HPV) testing for women aged 30 years and older every 5 years, although this may increase testing and over treatment.
- Although HPV testing exists, it is not offered in all Canadian provinces and was not included in the guidelines. With time it is likely that HPV screening will be incorporated as a more targeted way to screen for cervical cancer and cervical cancer risk.