A study published in the New England Journal of Medicine on March 21 suggests that a pap test may not be sufficient to diagnose cervical cancer and that a vaccine could help.
The study was conducted by researchers at Massachusetts General Hospital and Massachusetts Institute of Technology and included 6,741 women who were enrolled in the Pap Test for Cancers Trial.
The women received an average of 16,700 pap smear tests before their cervical cancer diagnosis and were followed for 18 years, beginning when the women began having cervical cancer.
The researchers found that women who received the Pap test during the early phase of cervical cancer had a slightly higher than expected incidence of papillomas compared with those who received a vaccine during the late-stage cervical cancer screening and that vaccine efficacy was not associated with the duration of the Pap screening.
“The overall vaccine efficacy observed in this study is lower than we would expect based on the available data, as the vaccine was administered at the time of the diagnosis of cervical and ovarian cancer,” said senior author Michael A. Schmitt, MD, PhD, professor of pediatrics at Massachusetts Institute and director of the Center for Vaccine Research and Development at Massachusetts.
The authors noted that a Pap test has not been validated as an effective tool for detecting cervical cancer in patients who have already undergone a Pap smear.
The findings were based on a meta-analysis of 17,906 women who had completed the Paptest for Cancer Trial, which included data from more than 5,600 women who underwent screening, according to the study.
The vaccine efficacy in women who did not receive the Pap exam, however, was comparable to that in women that received the vaccine during their screening, the researchers said.
“Although our results do not support the use of Pap test for Carcinogenesis Screening in patients with cervical cancer, this study provides further evidence that Pap test is an effective, noninvasive, and nonpharmacologic diagnostic tool in cervical cancer,” the authors concluded.