Smear and HPV Testing

Why does screening work?

Thanks to the screening practices that became widespread in the middle of the 20th century, the rates of occurrence of and death from cervical cancer have fallen markedly over the past 50 years.

Screening detects the precancerous changes that can progress to cancer if they are not treated. In the United States it is estimated that around 200,000 women each year need treatment for a precancerous change.

Against this, largely because screening recommendations are not followed, it was projected that in 2025 there would be 13,360 new diagnoses of cervical cancer and 4,320 deaths in the United States. The problem, in other words, is not that screening is ineffective but that it is not done.

The difference between a smear and an HPV test

The smear (Pap) test looks at cells: it examines whether there is a change in the cells taken from the cervix. It has been effective in reducing the rates of occurrence of and death from cervical cancer.

The HPV test, on the other hand, looks not at the cell but at the cause: it looks for the presence of the high-risk HPV types that can lead to cancer. The HPV test is more sensitive and, when the result is negative, gives stronger reassurance that there is no cancer.

For this reason screening with the HPV test alone (primary HPV screening) has become the preferred method in guidelines both in the United States and worldwide.

How is screening planned?

• Primary HPV screening is the preferred method, to be done every 5 years from the age of 25 (ACS 2020).
• When the sample is taken from the cervix by a doctor and the result is negative, it is recommended that screening be repeated every 5 years.

How the guidelines reached their present form is also instructive: in 2002 co-testing (HPV plus examination of the cells) every three years was recommended; in 2012 co-testing every five years became the preferred method; and in 2020 primary HPV screening every five years from the age of 25 became the preferred approach.

Self-collected samples

In 2024 and 2025, HPV testing on a sample collected by the person themselves from the vagina was approved. With this method there is no need to use an examination instrument (speculum).

According to the consensus recommendations published in 2025 and the ACS, which adopted them:

• Primary HPV screening on a cervical sample taken by a doctor is preferred.
• A vaginal sample collected by the person themselves is an acceptable option for people aged 25–65 at average risk.
• If an HPV test on a self-collected sample is negative, it is recommended that it be repeated after 3 years (not the 5 years that apply to a doctor-taken sample).

It is stated that this approach may overcome barriers to accessing screening. But there are two cautions: most of those whose HPV test is positive need further assessment steps, and the data on the method's long-term real-world effectiveness are still limited. In some higher-risk people a sample taken by a doctor continues to be recommended.

When is screening stopped?

Because of the frequency of cervical cancer seen in women over 65 and inadequate adherence to the criteria for stopping screening, the ACS updated its 2020 guideline. For screening to be brought to an end in a person at average risk:

• The primary HPV tests done at ages 60 and 65 must be negative (preferred), or the tests in which HPV testing and examination of the cells are done together must be negative (acceptable).
• If these tests are not available, three consecutive negative examinations of the cells done at the recommended interval, the last of them at the age of 65, is acceptable.
• If testing is done on a self-collected sample, a 3-year interval should be followed.

It is a condition that the last HPV test not be at an age younger than 65.

The HPV vaccine

The HPV vaccine offers an important opportunity for protection from cancer. According to US data, in the period 2012–2016 an average of 34,800 cancers a year were attributed to HPV infection. 92% of these (32,100 cases) — cancers of the cervix, oropharynx, anus, vagina, vulva and penis — are due to the types targeted by the nine-valent vaccine.

Who is it recommended for?

• It is recommended routinely at age 11 or 12; vaccination can be started from the age of 9.
• It is recommended for everyone up to the age of 26 who has not been adequately vaccinated.
• In some inadequately vaccinated adults aged 27–45 it may be considered through a shared decision with the doctor. It is stated that most adults in this age group will not benefit from the vaccine.
• The vaccine is not licensed for adults over 45.

Why vaccinating at a younger age matters

The vaccine has been shown to be more effective at younger ages: being vaccinated at 12–13 is markedly more effective than at 14–15, which in turn is more effective than being vaccinated in late adolescence and early adulthood. The American Cancer Society encourages recommending the vaccine from the age of 9 or 10, stating that routine vaccination between the ages of 9 and 12 would raise on-time vaccination rates and thereby increase the number of cancers prevented.

No evidence has been found that the protection given by the vaccine decreases over time.

Is testing needed before vaccination?

No. Doing a smear or HPV test before vaccination in order to decide whether the vaccine is appropriate is not recommended. The recommendations apply to everyone, regardless of behavioural or medical risk factors for HPV infection.

Pregnancy and breastfeeding

In pregnant women HPV vaccination is postponed until after the pregnancy; but there is no need for a pregnancy test before vaccination. People who are breastfeeding can be vaccinated.