What are the guidelines for Pap smear screening in females between 21 and 65 years old with varying medical histories?

Pap Smear Screening Guidelines for Women Ages 21-65

When to Start Screening

Cervical cancer screening should begin at age 21 years, regardless of sexual history or age of sexual debut. 1, 2

• Screening before age 21 causes more harm than benefit because abnormal results in younger women are typically transient and resolve spontaneously, while treatment can adversely affect future childbearing 1
• The process of HPV-related cervical carcinogenesis involves multiple steps and is generally not rapid, even with early sexual exposure 1

Screening Intervals by Age Group

Ages 21-29 Years

Screen every 3 years with cervical cytology (Pap test) alone. 1, 2

• HPV testing should NOT be used in this age group, either alone or in combination with cytology 1
• Annual screening provides minimal additional benefit while substantially increasing harms from unnecessary procedures and treatment of transient lesions 1, 2

Ages 30-65 Years

The preferred strategy is co-testing (Pap test plus HPV test) every 5 years. 1, 2

• An acceptable alternative is cytology alone every 3 years 1, 2
• Co-testing every 5 years provides comparable benefits and harms to cytology alone every 3 years 1, 2
• Women choosing co-testing should understand that 11% of women aged 30-34 and 2.6% of women aged 60-65 will have normal cytology but positive HPV results, requiring additional surveillance 1

Critical caveat: Adherence to recommended intervals is essential—screening more frequently (e.g., annually) dramatically increases harms without meaningful benefit 1, 3

When to Stop Screening

Standard Cessation at Age 65

Stop screening at age 65 if ALL of the following criteria are met: 1, 4, 2

1. Adequate prior negative screening: Either 3 consecutive negative Pap tests OR 2 consecutive negative co-tests within the past 10 years 1, 4, 5
2. Most recent test within the past 5 years 1, 4, 5
3. No history of CIN2, CIN3, adenocarcinoma in situ, or cervical cancer in the past 20-25 years 4, 5

• Once screening is discontinued, it should NOT resume for any reason, even with a new sexual partner 5
• The ratio of colposcopies to life-years gained becomes very large beyond age 65 in regularly screened women, making continued screening inefficient 4, 5

Critical Exceptions: Continue Screening Beyond Age 65

You MUST continue screening past age 65 in these situations: 4, 5

1. History of high-grade lesions: Continue for at least 20-25 years after treatment for CIN2, CIN3, or adenocarcinoma in situ, even if this extends screening well past age 65 4, 5
2. Inadequate screening documentation: If prior screening history cannot be verified, continue screening until cessation criteria are met 1, 4, 5
3. Never or rarely screened: Women who have never been screened should receive at least 2 negative tests one year apart, regardless of age 4, 5
4. Immunocompromised status: Including HIV infection or other causes of immunosuppression 4, 5
5. High-risk factors: Multiple sexual partners, history of HPV infection, smoking, pessary use 5

Early Cessation Before Age 65

Stop screening at any age if: 1, 4, 5

• Total hysterectomy with removal of the cervix for benign reasons (confirmed by surgical records or examination) 1, 4, 2
• Life expectancy is severely limited 4

Do NOT stop screening after hysterectomy if: 1, 2

• History of CIN2, CIN3, adenocarcinoma in situ, or cervical cancer
• Cervix remains in place (supracervical hysterectomy)

Common Pitfalls to Avoid

Overscreening is the most common error in practice: 3

• 55% of American women undergo annual Pap smears despite recommendations for 3-year intervals 3
• Even 38% of women aged 75-84 and 20% of women aged 85+ report annual screening 3
• This excessive screening increases false positives, unnecessary colposcopies, and treatment of lesions that would spontaneously resolve 1, 3

Screening women who should not be screened: 2

• An estimated 14 million eligible women aged 21-65 have not been screened within the past 3 years, while many women over 65 with adequate prior screening continue to be screened unnecessarily 6
• Focus efforts on under-screened populations: recent immigrants, uninsured women, and those without a usual source of healthcare 6

Failure to document adequate prior screening before stopping at age 65: 4, 5

• Between 28-64% of women aged 65+ have never had a Pap smear or have not had one within 3 years 5
• Always verify screening history before discontinuing—if unavailable, continue screening until criteria are met 1, 4