Regular Pap Smear Boosts Cervical Cancer Survival: Study
Screening is important even after HPV vaccine, experts say
THURSDAY, March 1, 2012 (HealthDay News) -- Women who have regular Pap tests to screen for cervical cancer are more likely to survive if they are ever diagnosed with the disease, a new Swedish study suggests.
Compared to women whose cervical cancer is detected because of symptoms, those diagnosed after a routine Pap smear increased their cure rate from 66 percent to more than 90 percent, the researchers said.
"Regular Pap screening does not just prevent cancer by looking for precursors, but it also increases the possibilities of cure if the cancer is detected during screening," said lead researcher Dr. Bengt Andrae, of the Centre for Research and Development at Uppsala University. "We can say the benefit of Pap smear screening is real."
In a Pap smear, cells scraped from the opening of the cervix are examined under a microscope. This year, more than 12,000 women in the United States will be diagnosed with cervical cancer, and more than 4,000 will die from it, according to the U.S. National Cancer Institute.
For the study, published in the March 1 online edition of the BMJ, Andrae's team collected data on more than 1,200 Swedish women diagnosed with cervical cancer from 1999 to 2001.
The researchers found 92 percent of the women who were screened regularly were cured, compared with 66 percent of the women diagnosed once symptoms had developed.
Cure rates were also higher among women screened according to established guidelines, compared to women who were overdue for a Pap test, they found. Of nearly 400 women who died from cervical cancer, 75 percent had not had a Pap test within the recommended time.
Dr. Jennifer Wu, an obstetrician-gynecologist at Lenox Hill Hospital in New York City, said that "this is what we expected. Pap smears are good preventive measures for trying to catch cervical cancers early."
With cervical cancer, symptoms don't appear until the cancer has spread to other parts of the body. At that point, the cancer is in an advanced stage, which is difficult to treat, she said.
"In patients that go for yearly checkups, we usually catch these problems before they become cervical cancer," she said. "Or, if there is cervical cancer it is in an early stage where the chances of survival are greatest."
Guidelines from the American Cancer Society recommend that screening for cervical cancer start three years after a woman becomes sexually active, but no later than age 21. Screening should be done every year or every two years after that.
At age 30, if a woman has had three normal Pap tests in a row, she can be screened every three years. After age 70, if Pap tests have been normal for 10 years and three tests in a row, certain women may stop screening altogether, according to the guidelines.
However, Wu said she thinks sexually active women with different partners should be screened every year, regardless of previous findings.
The new vaccine to protect against the human papillomavirus (HPV) will protect women against about 70 percent of cervical cancers. But Andrae said even women who have been vaccinated need to continue Pap smears.
"The vaccine doesn't cover all HPV types. It covers the worst type, but there are still HPV types not covered, and you need to be screened for those," he said. "And also, you may have been infected before you were vaccinated and the vaccine won't do any good. That's why you have to go on being screened."
Many people are afraid screening might find cancer, so avoid these tests that could save their life, Andrae said. "You shouldn't fear what might be found in screening. Regular Pap smear screening is effective," he said.
Some screenings, such as the PSA (prostate-specific antigen) test for prostate cancer, are less efficient, because abnormal findings can result in unnecessary treatment, Andrae said. But the Pap screening "is as good as we thought," he said.
For more information on cervical cancer, visit the American Cancer Society.