Last week I lamented that we can prevent so few cancers.  Cervical cancer screening is one of the success stories of prevention.  Regular pap smears can drastically decrease the risk of cervical cancer and makes death from cervical cancer virtually unheard of.

Cervical cancer is a sexually transmitted disease, caused by human pappilomavirus (HPV).  Pap smears check for telltale changes in the cervix that happen after HPV infection.   Over many years these changes lead to cervical cancer.

But while potentially life-saving for some women, other women can not benefit from pap smears and should not have them.  A study in this issue of the Annals of Internal Medicine interviewed physicians about the kinds of patients to whom they would recommend pap smears and found that many doctors perform pap smears on women for whom it is not helpful.

Below is a summary of the U.S. Preventive Services Task Force recommendations for pap smears.  More details are available by following the links below.

  • Women who have been sexually active and have a cervix should have pap tests. Pap tests should begin within 3 years of onset of sexual activity or age 21, which ever comes first, and should be repeated at least every 3 years.
  • Women older than 65 who have had recent normal pap smears should not have further pap tests. This is because cervical cancer this late in life is very rare and would have already caused abnormal pap smears.
  • Women who no longer have a cervix because of a hysterectomy for a benign disease (that is, not for cancer) should not have further pap tests. That’s because it’s impossible to get cervical cancer without a cervix.

Like all good things, the benefit is derived from judicious use.  Even though in other women the test is crucial, performing pap tests on women who can not benefit from it is just bad medicine.  It falsely reassures women that they are taking care of themselves.  It wastes patients’ time and scarce resources.  And it ultimately decreases physician credibility.

Learn more:

U.S. Preventive Services Task Force recommendations for cervical cancer screening

Wall Street Journal Health Blog:  Who Should Get a Pap Smear?

Annals of Internal Medicine article:  Specialty Differences in Primary Care Physician Reports of Papanicolaou Test Screening Practices: A National Survey, 2006 to 2007