What are the Canadian guidelines for cervical cancer screening?

Canadian Guidelines for Cervical Cancer Screening

The Canadian guidelines recommend cervical cancer screening with cytology (Pap test) every 3 years for women aged 21-29 years, and either cytology every 3 years or HPV testing with cytology (cotesting) every 5 years (preferred) for women aged 30-65 years. 1

Age-Based Screening Recommendations

Under 21 years

• No screening recommended regardless of sexual activity or other risk factors 1

Ages 21-29 years

• Screening with cytology (Pap test) alone every 3 years 2, 1
• HPV testing is not recommended for routine screening in this age group 2
• Reflex HPV testing may be used to assess women aged 25-29 with ASC-US results 2

Ages 30-65 years

• Preferred: Cotesting (HPV + cytology) every 5 years 2, 1
• Acceptable alternative: Cytology alone every 3 years 2, 1
• Primary HPV testing every 5 years is emerging as a preferred strategy in some provinces 1, 3

Over 65 years

• Discontinue screening if:
  • Adequate prior screening with normal results (3 consecutive negative cytology tests or 2 consecutive negative cotests in the past 10 years, with most recent test in past 5 years) 2
  • No history of high-grade squamous intraepithelial lesions (HSIL), adenocarcinoma in situ, or cancer 2, 1

Special Populations

Women who have had a hysterectomy

• Discontinue screening if total hysterectomy with removal of cervix and no history of HSIL, adenocarcinoma in situ, or cancer 2, 1
• Continue routine screening if subtotal (supracervical) hysterectomy 1

High-risk women

• Women with HIV infection, compromised immune system, in utero exposure to diethylstilbestrol, or previous treatment of high-grade precancerous lesion or cervical cancer should receive individualized follow-up 2, 1
• Women with history of CIN 2/3 should continue screening until three consecutive negative cytology tests within a 10-year period 1

Pregnant women

• More conservative management is recommended 2
• Colposcopy is preferred for pregnant women with LSIL, but deferring until 6 weeks after childbirth is also an option 2
• Treatment of CIN 1 is not recommended during pregnancy 2
• For pregnant women with CIN 3, treatment can wait until after delivery 2

HPV-vaccinated women

• Follow the same screening recommendations as unvaccinated women 2, 1

Management of Abnormal Results

• CIN 1 should not be treated in any age group unless persistent for 2 years 2, 1
• More conservative management is recommended for young women aged 21-24 years 2
• For women aged 21-24 years with HSIL, colposcopy is recommended but immediate treatment is not 2
• Young women aged 21-24 years with CIN 3 should be treated with a diagnostic excisional procedure 2
• Women older than 65 years should continue to be screened if they have ASC-US, even if they are HPV-negative 2

Important Considerations

• Annual screening is not recommended for any age group 2
• HPV testing should not be used as a stand-alone test for screening in most settings 2
• Despite recommendations, Canadian women have shown preferences for screening every three years compared to every five or ten years, and initiating screening at age 21 compared to age 25 or 30 4
• Approximately 50% of cervical cancers occur in women who have never been screened or who have not been screened in the past 5 years 1

Screening Effectiveness

• Cervical cytology screening has decreased cervical cancer incidence and mortality by over 70% in Canada 1
• HPV-based screening provides 60-70% greater protection against invasive cervical cancer compared to cytology-based screening 1
• The focus should be on ensuring women receive adequate screening, appropriate evaluation of abnormal results, and indicated treatment, regardless of which screening strategy is used 2