Cervical cancer was once the leading cause of cancer-related deaths in American women. In the 1930s, more American women died of cervical cancer than any other kind of cancer, including breast or lung. But in 1943, a new method for cervical screening was introduced. The Babeș-Papanicolaou test (named after physicians who pioneered the method), also called a “Pap smear” or “Pap test,” became the most successful cancer screening in history. Today, according to the American Cancer Society, there are fewer than 4,000 annual deaths due to cervical cancer, mostly among women who have never been screened.
Until now, physicians recommended that women receive an annual Pap test, starting sometime in the teens. So when the U.S. Preventive Services Task Force issued a set of new guidelines for cervical cancer screening on March 15, 2012, it introduced a significant change to women’s health care routines. Now, the guidelines suggest screening should begin no earlier than age 21, and for most women over the age of 30, the tests can be safely spaced three years apart. Similar guidelines released by the American Cancer Society on March 14 support that approach.
“In the case of Pap tests, it turns out that more was not better,” explains Lily Tsai, MD, a Scripps gynecologist. “In recent years, as we have come to understand the natural history of HPV infection, we’ve seen convincing evidence that over-screening can cause harm to patients, both physical and psychological.”
Nearly all cervical cancers are the result of infection with the human papillomavirus (HPV) — a fact that was not established until recently. But not all HPV infections will cause cervical cancer. “It turns out that most people fight off HPV infections naturally without intervention,” Dr. Tsai says. “So annual Paps were identifying abnormal cells at a very early stage of infection or were non-diagnostic, leading anxious patients and providers to treat them more aggressively than was necessary.”
The most common diagnostic procedure for suspicious Pap results is a colposcopy, or magnified examination of the cervix. If abnormal areas are visualized, additional studies such as cervical biopsy or endocervical curettage may be performed and examined in the lab for precancerous changes. A confirmed high level abnormality often leads to a cone biopsy of the cervix to remove affected tissue.
“Treatments are not always benign. An unnecessary cone biopsy, for example, may increase one’s chance of a weaker cervix, potentially leading to problems in pregnancy” says Dr. Tsai. Plus the anxiety caused by an abnormal Pap test is also significant.
The American College of Obstetricians and Gynecologists recommended spacing these screenings for appropriate women three years apart in 2009, and the American Society for Colposcopy and Cervical Pathology (ASCCP) issued similar guidelines in 2006. The recently released guidelines are now in alignment with those developed by experts in the specialty.
This does not mean, however, that women can skip their annual gynecological examination. “Pap tests are not the only reason to have an annual exam,” Dr. Tsai emphasizes. “Women still need to be examined yearly, either by their gynecologist or their primary care physician, for the remainder of the pelvic exam and breast exam.
The new guidelines suggest:
- For women with no other risk factors, Pap tests should start at age 21.
- Between the ages of 21 and 30, cervical cell screening should take place at three-year intervals, with no screening for HPV.
- After age 30, women should have a combined cervical smear and HPV test every five years or Pap test alone every 3 years.
- After the age of 65, women who have had previous normal results may discontinue Pap tests.
- If a woman has had serious cervical pre-cancer, she should continue being screened for 20 years after that diagnosis, even if she is past 65.
- Women with additional risk factors (including previous abnormal Pap tests, exposure to diethylstilbestrol (DES) in utero, or a compromised immune system), Pap tests should be more frequent.
- If a woman has had a hysterectomy with removal of the cervix for benign reasons, there is no need for a Pap test.