Cervical Cancer Screening Guidelines: Who to Screen, When to Screen, and How

Mar 29

Written By The OB/GYN Resident Survival Guide

Cervical cancer screening is one of those topics that comes up constantly in clinic, on exams, and in everyday patient counseling. Despite being one of the most well-established screening protocols in medicine, the guidelines can feel confusing with multiple organizations, different age cutoffs, and evolving recommendations around HPV testing. In this episode, I break down the current cervical cancer screening guidelines so you can feel confident knowing who to screen, when to screen, and how.

Before we get into the clinical content, a special congratulations to all of you who matched to residency this past week!! It's truly such an exciting time. I would love to know where you matched and into what specialty. Send me a message on Instagram or by email at info@drkcmiller.com.

If you matched into OB/GYN, don't forget to download the OB/GYN Residency Starter Pack: A 5-Step Guide for Incoming Interns. It's a free guide that covers what suture skills to practice, apps to download, which practice bulletins to review leading up to July 1st, and more. The link to download is in the show notes or you can grab it here.

I also want to give a special shout out to those of you who did not match this year. Please know that this is not the end of the road for you. You absolutely have a place and a future in medicine. There are many excellent physicians and physician content creators who themselves did not match the first or second time around and have made some very encouraging content about that period in their lives. I've linked at least one of those videos here. If you need a little encouragement or want to connect, feel free to reach out to me.

Whose Guidelines Are These?

The guidelines reviewed in this episode are endorsed by multiple major organizations, including the American College of Obstetricians and Gynecologists (ACOG), the Society of Gynecologic Oncology (SGO), the American Society for Colposcopy and Cervical Pathology (ASCCP), and the United States Preventive Services Task Force (USPSTF). Cervical cancer is one of the few cancers where screening recommendations are largely unified across multiple organizations.

These recommendations are specifically for average-risk patients, meaning individuals who are not immunocompromised, do not have a known history of high-grade cervical histology, and have no known in utero exposure to diethylstilbestrol (DES).

When Do We Start and Stop Cervical Cancer Screening?

Start: Age 21. Screening should begin no earlier than age 21. As HPV vaccination rates continue to increase, this may eventually be pushed out to age 25 (as recommended by the American Cancer Society), but for now, while vaccination rates remain below target levels in the United States, ACOG, ASCCP, and SGO continue to recommend starting at 21. Remember, the HPV vaccine was only introduced in the U.S. in 2006, so we are still building up the number of vaccinated individuals in the population.

Stop: Age 65 (if adequate prior screening with negative results). Adequate prior screening is defined as:

3 consecutive negative cytology results, OR
2 consecutive negative co-testing results, OR
2 consecutive negative primary high-risk HPV test results

All within the 10 years prior to discontinuing screening.

How Do We Screen?

Ages 21 to 29

For patients aged 21 to 29, screening is done with cytology alone every 3 years. No HPV testing is included in this age group as a default.

That said, the newer FDA-approved primary high-risk HPV screening tests are acceptable for use starting at the age of 25, performed every 5 years. So if a patient wants to transition from cytology-based testing to primary high-risk HPV testing at 25, this is supported by ACOG, ASCCP, and SGO.

The more we have learned about cervical cancer and precancer, the more we understand that the presence or absence of high-risk HPV strains tells us significantly more about a patient's cervical cancer risk than cytology does. It is possible that one day, screening with cytology will be phased out entirely, but we are not there yet.

Ages 30 to 65

For patients between the ages of 30 and 65, there are three acceptable screening options:

Primary high-risk HPV testing every 5 years (this is actually the preferred, gold standard method per SGO)
Cervical cytology alone every 3 years
Co-testing (cytology + high-risk HPV testing) every 5 years

When to Continue Screening Beyond Age 65

While average-risk patients with adequate prior negative screening can stop at 65, there are several important exceptions. About 20% of cervical cancers occur in patients older than 65, so it is important to identify who still needs ongoing surveillance.

1. History of treated high-grade histology or cytology. Patients with a history of CIN 2, CIN 3, AIS, HSIL, or persistent ASC-H should continue screening at 3-year intervals (after the initial post-treatment surveillance period) for at least 25 years after treatment, even if that extends beyond age 65.

2. Never adequately screened. If a patient establishes care at age 68, for example, and has never had a Pap smear or has not been screened in the last 10 years, screening should not be skipped simply because they are older than 65.

3. Immunocompromised patients. This includes patients with HIV. Screening should continue throughout their lifetime, regardless of age.

4. History of hysterectomy with prior high-grade disease. Even after a total hysterectomy (cervix removed), patients with a history of CIN 2 or greater within the last 25 years should continue surveillance every 3 years for 25 years, even if that extends beyond age 65.

Summary

For the average-risk patient:

Cervical cancer screening should begin at age 21 and can stop at age 65, provided the patient has had adequate prior screening with negative results within the past 10 years.
Ages 21 to 29: Cytology alone every 3 years. Primary high-risk HPV testing is acceptable starting at age 25, performed every 5 years.
Ages 30 to 65: Primary high-risk HPV testing every 5 years (preferred), co-testing every 5 years, or cytology alone every 3 years.
Continue beyond 65 for patients with treated high-grade histology (even post-hysterectomy) who have not yet completed 25 years of surveillance, patients who have never been adequately screened, and immunocompromised patients.