Pap smears, also known as Pap tests, are screening tests for cervical cancer. They involve collecting cells from the cervix and examining them under a microscope to look for precancerous changes or early signs of cancer.
The Pap test has been credited with dramatically reducing deaths from cervical cancer. When detected early, cervical cancer is one of the most successfully treatable cancers. Prior to the introduction of regular Pap screening, cervical cancer was a leading cause of cancer death for women.
Current guidelines recommend that women begin getting regular Pap tests at age 21 and continue getting them on a regular basis until age 65. After age 65, most major medical organizations recommend stopping Pap test screening if the previous tests have been consistently normal.
This raises the obvious question: Why stop at age 65? Why not continue to get Pap tests regularly for life? Below we will look at the reasoning behind the age 65 cutoff recommendation.
Why Age 65?
There are several reasons why Pap smear guidelines change for women over 65:
Most Cervical Cancer Happens Earlier in Life
Cervical cancer was previously most common in women in their 40s and 50s. However, due to the success of widespread Pap screening programs, the average age of a cervical cancer diagnosis has increased. It now most often occurs in women in their mid to late 50s. Still, it remains relatively rare over age 65.
According to the American Cancer Society, about 15% of new cervical cancer cases are diagnosed in women over 65. The vast majority of new cases (75%) are found in women younger than 50.
This distribution of cervical cancer cases reflects the typical progression of the disease. Cervical cancer usually takes 10-20 years to develop. Abnormal cells first turn precancerous and then finally progress to true cancer. This process usually takes decades and often life events like childbirth play a role.
Since the cancer develops slowly over many years, most concerning cellular changes happen earlier in life. Regular Pap tests detect these precancerous changes so they can be treated before cancer actually develops.
Risk Factors Decline for Older Women
Two major risk factors for cervical cancer also decline with age:
- HPV infection – HPV stands for human papillomavirus. There are over 150 strains of the HPV virus, but only certain “high-risk” strains can lead to cervical cancer. HPV is extremely common in younger women and is transmitted through sexual contact. However, the body’s immune system often clears the infection on its own. By age 65, most women will have either cleared an HPV infection or developed cellular changes that were caught by Pap tests.
- Smoking – Cigarette smoking is another important risk factor for cervical cancer. However, smoking rates decline significantly in older age groups. According to the CDC, only 8.4% of women over 65 were current smokers compared to 13.5% of women aged 45-64.
With lower rates of HPV infection and smoking, older women are much less likely to develop significant cervical cell changes that could lead to cancer.
Life Expectancy Declines
Average life expectancy also plays a role in the decision to stop screening at age 65. In the US, women’s life expectancy is around 81 years. Cervical cancer is slow growing, so most women diagnosed with early stage cervical cancer after age 65 are likely to die of another cause before the cancer becomes deadly.
Continued Pap testing would have little impact on life expectancy for an otherwise healthy women with a normal prior Pap history. Discontinuing testing avoids unnecessary procedures and anxious follow up in a population with limited remaining life span.
Potential Harms Outweigh Benefits
All screening tests have limitations and come with potential risks and side effects. For older women, the harms and costs of continued testing are thought to outweigh the potential benefits.
Potential downsides of continuing Pap smears after age 65 include:
- False Positive Results – Abnormal Pap results are more common in post-menopausal women due to hormonal changes, but most of these tests come back normal on repeat testing. Anxiety and costs increase due to additional testing.
- Overdiagnosis – Detection and treatment of cellular changes that would never have actually progressed to cancer.
- Procedure-Related Risks – Discomfort, infection, bleeding from the Pap procedure. Risks increase if follow up biopsies or treatments are necessary.
Since most elderly women are at low risk for cervical cancer, the harms of continued testing are believed to outweigh finding the rare case of actual cancer.
Who Should Delay Stopping Screening?
Some women over 65 who are at higher risk for cervical cancer may benefit from continued Pap tests. This includes:
- Women with history of precancer or cervical cancer treatment. An estimated 50% of cervical cancer cases occur in women who have not had regular Pap screenings.
- Women with compromised immune systems, such as from HIV, organ transplant, or chronic steroid use. The immune system often clears HPV infection before cancer can develop.
- Women who were exposed to diethylstilbestrol (DES) before birth. DES was sometimes prescribed to prevent miscarriage but increased risk of certain cancers in the daughters.
Women over 65 who have had normal prior Paps and are not high risk should feel comfortable stopping screening. But those with risk factors or history of abnormal Paps should discuss continued screening with their doctor.
What About HPV Testing?
HPV or human papillomavirus testing is sometimes used in conjunction with the Pap smear to screen for cervical cancer.
HPV testing looks for infection with the strains of HPV virus known to cause cancer. A positive HPV test signals that a woman has been exposed to a cancer-causing virus strain.
HPV testing is not recommended for most women over 65. The harms of HPV testing likely outweigh benefits for the average elderly woman.
HPV infection usually clears within 1-2 years, especially in older women with stronger immune response. A positive HPV test in an older woman will usually not progress to precancer or cancer within her remaining lifetime. But it may trigger unnecessary additional testing and treatment.
However, HPV testing with Pap tests may help guide decisions in older women found to have abnormal cervical cell changes. If HPV is detected along with an abnormal Pap, it signals a higher risk that the changes could progress to cancer.
The Bottom Line
While cervical cancer screening has been invaluable in reducing cancer deaths, it does come with some potential downsides and risks. For low risk women over the age of 65, these potential harms appear to outweigh the small chance of benefit.
Women over 65 who have consistently normal Pap results can feel comfortable discontinuing routine screening. And of course, any symptoms like abnormal bleeding should prompt a prompt medical evaluation regardless of age or screening status.
The decision to stop screening is based on large population studies showing limited survival benefit for elderly women. But women should discuss Pap testing with their doctor based on their individual health profile and risk factors.
While screening intensity declines after 65, cervical cancer prevention does not end. Avoiding smoking and practicing safe sex remain important lifelong protections against HPV exposure and cervical cancer development.
Key Points
- Most major medical organizations recommend stopping routine Pap smear screening at age 65 for average risk women.
- The risk of cervical cancer declines significantly for older women due to lower HPV rates and reduced smoking.
- Potential harms like false positives, overdiagnosis, and procedure risk are thought to outweigh the benefits of finding rare cases of cancer.
- Women over 65 with history of abnormal Paps or higher cancer risk should discuss continued screening with their doctor.
- Stopping screening does not mean stopping prevention. Avoiding smoking and safe sex remain important at any age.