From the Guidelines
Pap smears are recommended every 3 years for women aged 21-29, and every 5 years with both the HPV test and the Pap test (preferred) or every 3 years with the Pap test alone (acceptable) for women aged 30-65. Women younger than 21 do not need screening regardless of sexual activity, as cervical cancer is rare in this age group and most HPV infections clear spontaneously 1. Women over 65 who have had adequate prior screening with normal results can discontinue screening, and those who have had a total hysterectomy (including removal of the cervix) for non-cancerous reasons can also stop screening. However, women with a history of cervical cancer, DES exposure before birth, HIV infection, or immunosuppression may need more frequent screening. These recommendations are based on understanding that cervical cancer develops slowly over time, and that too-frequent screening can lead to unnecessary procedures for transient HPV infections that would resolve on their own.
Some key points to consider:
- Women aged 21-29 years should receive cytology screening every 3 years with either conventional cervical cytology smears or liquid-based cytology 1.
- For women aged 30-65 years, the preferred approach is to be screened every 5 years with the combination of HPV testing and cytology (“cotesting”) 1.
- Women should discontinue screening after age 65 years if they have had 3 consecutive negative cytology tests or 2 consecutive negative cotest results within the 10-year period prior to ceasing screening, with the most recent test occurring within the last 5 years 1.
- Women at any age should NOT be screened annually by any screening method 1.
It's essential to note that these recommendations are based on the most recent and highest-quality evidence available, and your healthcare provider may recommend a different schedule based on your personal risk factors and medical history.
From the Research
Frequency of Pap Smears
- The frequency of Pap smears is recommended to be annual for women who have begun sexual activity until the age of 35, and at 5-year intervals after that, as stated in the study 2.
- This screening schedule can help reduce both the incidence and mortality rate from invasive cervical cancer.
- The study 2 also mentions that colposcopy is essential for evaluating patients with abnormal cervical smears, but it has no role as a primary screening procedure for cervical cancer.
Comparison with Other Screening Methods
- A study 3 compared PAP smear cytology with other screening tools, including visual inspection with acetic acid, Lugol's iodine, cervicography, and HPV testing, in women at different risk for cervical cancer in Brazil and Argentina.
- The study 4 analyzed the degree of agreement between HPV testing, Pap smear, and colposcopic directed cervical biopsies, and found a fair agreement between Pap smear and colposcopic biopsy.
- Another study 5 compared the conventional Pap smear and colposcopy in screening for cervical cancer in patients with secondary immunodeficiency, and found that colposcopy had higher accuracy, sensitivity, specificity, and negative predictive values than the Pap smear.
Predictive Value of Pap Smears and HPV Testing
- A study 6 assessed the clinical outcome of patients with conservatively treated cervical adenocarcinoma in situ (AIS), and found that HPV testing significantly predicted disease persistence/clearance, while the predictive power of Pap smear did not reach statistical significance.
- The combination of Pap smear and HPV testing was found to offer clear advantages over single cytology in monitoring women conservatively treated for cervical AIS, with a sensitivity of 90.0%, specificity of 50.0%, positive predictive value of 52.9%, and negative predictive value of 88.9% at the first follow-up visit 6.