Cervical Screening FAQs for Healthcare Providers

Most cervical cancers are caused by human papillomavirus (HPV).

HPV is a family of common viruses. There are more than 100 types of HPV and some types are considered to be oncogenic (cancer-causing). Currently, 13 types of HPV are known to be oncogenic, including types 16, 18 and 45. Persistent infection with oncogenic types of HPV can lead to abnormal cell changes in the cervix. If left untreated, these cell changes can lead to cervical cancer over time. Only abnormal cell changes that are caused by oncogenic types of HPV can lead to cervical cancer.

HPV is passed from one person to another through sexual activity. Sexual activity is defined as any sexual contact with another person, including any time someone has contact with another person’s genital (private parts). This contact can be with the hands, mouth or genitals. HPV infections are common and up to 80 per cent of sexually active people will have at least one HPV infection in their lifetime.

Most HPV infections go away on their own without causing any harm, but some infections will persist. It typically takes 15 to 20 years for persistent infections with oncogenic types of HPV to lead to cervical cancer.

Potential Benefits of Regular Cervical Screening

Getting screened regularly can find cervical pre-cancer and cancer earlier which may mean that:

• The chance of dying from cervical cancer is lower
• Treatment has a better chance of working
• Fewer treatments may be needed and the treatments may be less invasive (easier to handle)

Screening can be a part of taking an active role for patients in protecting their health. Getting a normal result from a cervical screening test can be reassuring for some people.

Potential Harms of Regular Cervical Screening

• False-positive: Getting an abnormal result when there is no HPV infection, pre-cancer or cancer present. False positive results can lead to extra testing, like a biopsy (taking a small sample of tissue), that can cause anxiety and stress for some people.
• False-negative: Missing an HPV infection, pre-cancer or cancer on a cervical screening test, which could lead to delayed treatment.
• Overdiagnosis: Finding an HPV infection, pre-cancer or cancer that would not otherwise cause health problems, that may lead to unneeded treatment.

Someone is eligible for cervical screening as part of the Ontario Cervical Screening Program if they:

• Have a cervix
• Are age 25 and older
• Have ever been sexually active
• Have Ontario Health Insurance Plan (OHIP) coverage
• Have no symptoms suggestive of cervical cancer

For more information about screening eligibility, see Cervical Screening Guidelines Summary.

The 5-year screening interval is consistent with knowledge about the natural history of cervical cancer. Evidence shows that getting screened with a cervical screening test every 5 years is as effective as getting screened with a Pap test every 3 years because the cervical screening test is better at detecting cervical pre-cancer and cancer. More frequent screening is not supported by evidence, which shows that the potential harms of shorter screening intervals outweigh the benefits. More frequent screening can result in more false-positives and more referrals to colposcopy, which causes unnecessary anxiety and discomfort.

Some of the evidence also suggests that the protective effect of a negative HPV test extends beyond 5 years. However, because this is an area of evolving evidence, the OCSP chose a screening interval of 5 years based on the precautionary principle (i.e., when there are potential harms, prevention should be the priority if there is any scientific uncertainty).

Most people can stop screening if they had 1 negative human papillomavirus (HPV) test result from age 65 to 69.

The following people should screen until age 74:

• People who did not have a cervical screening test from age 65 to 69
• Immunocompromised populations
• People ages 65 to 69 who have been discharged from colposcopy and have been advised to screen every 2 years because they have not yet met the criteria to return to routine screening

People with a positive HPV test result from age 65 to 69 should follow the cervical screening pathway until they have a negative HPV test result or until they are age 74, whichever occurs first.

People age 70 to 74 with a positive HPV test resultshould be referred to colposcopy.

Cervical screening is not recommended for people age 75 and older.

For more information about the screening cessation criteria, see Cervical Screening Guidelines Summary.

The following people should screen more often than every 5 years:

• Immunocompromised populations (see How often should I screen people who are immunocompromised?)
• People with human papillomavirus (HPV)-positive (other high-risk types) and low-grade or normal reflex cytology test results (see What are the next steps for people with HPV-positive [other high-risk types] test results?)
• Some people who have been discharged from colposcopy to primary care (see How often should I screen people who have had a colposcopy and have been discharged back into primary care?)

People who are immunocompromised should get screened every 3 years if their last cervical screening test result was negative.

The Ontario Cervical Screening Program defines immunocompromised populations as:

• People who are living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), regardless of CD4 count
• People requiring treatment (either continuously or at frequent intervals) with medications that cause immune suppression for 3 or more years
• Organ transplant recipients (solid organ or allogeneic stem cell transplants)
• People who are living with systemic lupus erythematosus, regardless of whether they are receiving immunosuppressant treatment
• People with congenital (primary) immunodeficiency
• People who are living with renal failure and require dialysis

People who are positive for HPV types 16, 18 or 45 will receive a test result of “HPV-positive (types 16, 18/45).”

People with HPV-positive (types 16, 18/45) test results should be referred to colposcopy, regardless of their reflex cytology test result.

People who are positive for HPV types other than 16, 18 or 45 will receive a test result of “HPV-positive (other high-risk types).”

The next steps for people with HPV-positive (other high-risk types) test results is based on their reflex cytology test result and screening interval.

Recommendations for people being screened in 5 years (or 3 years if immunocompromised) include the following:

• People with HPV-positive (other high-risk types) and low-grade or normal reflex cytology test results should repeat their screening test in 2 years. This allows time for the HPV infection to clear on its own.
• People with HPV-positive (other high-risk types) and high-grade reflex cytology test results should be referred to colposcopy.

Recommendations for people being screened in 2 years after a previous HPV-positive (other high-risk types) test result include the following:

• People who are HPV-positive (regardless of HPV type and reflex cytology test result) at the 2-year re-screen should be referred to colposcopy because continuing to test positive indicates persistent infection.
• People who are HPV-negative at the 2-year re-screen can return to average risk screening in 5 years, immunocompromised screening in 3 years or stop screening if cessation criteria have been met.

People who are immunocompetent with negative HPV test results should screen again in 5 years. People who are immunocompromised should screen again in 3 years.

Providers should repeat the HPV or cytology test using the Ontario Cervical Screening Program (OCSP) requisition form.

Invalid HPV test results

• An HPV test should be repeated at the participant’s earliest convenience, preferably within 3 months.
• People with two consecutive invalid HPV test results within a 21-month period should be referred to colposcopy.

Unsatisfactory reflex cytology test results

• People who are HPV-positive (other high-risk types) with an unsatisfactory reflex cytology test result should have a repeat standalone cytology test within 3 months. If someone has two consecutive unsatisfactory cytology test results within a 21-month period, they should be referred to colposcopy.
• People who are HPV-positive (types 16, 18/45) with an unsatisfactory reflex cytology test result should be referred to colposcopy.
• The use of transition-related hormone therapy (i.e., androgen therapy) in transmasculine and nonbinary people has been associated with a higher rate of unsatisfactory cytology test results. A course of intravaginal estrogen therapy can be considered after an unsatisfactory cytology test result in people who have had androgen therapy and in post-menopausal people.

People who have been discharged from colposcopy should resume screening in 2 years, 3 years or 5 years, depending on their cytology result at referral, immune status, histology and cytology test results, human papillomavirus status at discharge and whether treatment was required before discharge from colposcopy. A colposcopist should indicate the next cervical screening interval in primary care on the discharge summary.

For post-discharge screening recommendations, see Cervical Screening Guidelines Summary.

People should be referred back to colposcopy if they have been screened 2 years after being discharged and have a human papillomavirus (HPV)-positive test result, regardless of HPV type or reflex cytology.

People who have undergone a subtotal hysterectomy and retained their cervix should continue to follow the Ontario Cervical Screening Program’s (OCSP’s) cervical screening recommendations.

For people who have undergone a total hysterectomy and have had their cervix removed, see the OCSP’s Vaginal Vault Testing Guidance.

If someone has a negative HPV test result, they are not at elevated risk for developing cervical cancer.

The cervical screening test checks for types of HPV that can sometimes cause cervical cancer. It does not check for other types of HPV, such as those that cause genital warts.

The types of HPV that cause genital warts are non cancer-causing. Although these types of HPV may cause changes to the cells of the cervix, they never progress to cervical cancer.

View or download these resources from Ontario Health (Cancer Care Ontario) to share with your patients:

• What you should know about cervical screening
  • Cervical Screening Fact Sheet – English
  • Cervical Screening Fact Sheet - French
• After a cervical screening test