Cervical cancer screening is easily done with a pap smear. The pap smear has successfully reduced mortality from cervical cancer since it was introduced in mid 20th century. We now know that nearly 100% of cervical cancer specimens will test positive for a virus called human papillomavirus (HPV).
Who should be screened?
All women over the age of 21.
How often? At least every 3 years in those 21 to 29 and at least every 5 years in those older than 30 as long as the results are normal. Some need more frequent screening–like those with HIV, immunosuppression, or those with history of abnormal pap smears.
What is HPV?
It is a virus that is sexually transmitted. It is thought that most sexually active people have been exposed to HPV in their lifetime. Most people’s body clears the virus, but in some individuals the virus causes changes in the cells of the cervix which over time can change into cancerous cells.
Why not start pap smears before 21?
We want the body to have a chance to clear the HPV. Realistically-speaking, the median age of first sexual encounter is age 17. Most HPV infections are transient and will become undetetctable within one to two years. Only persistent infections are at risk for becoming cancer. It takes many years for these cellular changes to occur, thus screening at age 21 is suggested. If screening occurs earlier than age 1, this is likely to lead to unnecessary (and painful!) procedures in patients whom cellular changes were likely to clear without intervention.