Pap Test Improves Cervical Cancer Outcomes
Among women diagnosed with invasive cervical cancer, the odds of surviving are better when the cancer is detected by Pap testing than when the cancer is detected because of symptoms. These results were published in the British Medical Journal.
Cancer screening refers to the use of tests to detect cancer in individuals who do not have any symptoms of the disease. In general, the primary goal of screening is to reduce cancer deaths by detecting cancer at an earlier and more treatable stage. For some types of cancer—including cervical cancer—screening can also play a role in cancer prevention. Screening for cervical cancer can identify precancerous changes to the cervix. Treatment of these precancers can then prevent the development of invasive cancer.
The Pap test is a screening test that has had a tremendous impact on cervical cancer incidence and mortality. During a Pap test, a sample of cells is removed from the cervix and evaluated under a microscope. If the cells appear abnormal, additional testing is often recommended.
More recently, tests for high-risk types of human papillomavirus (HPV) have also been incorporated into cervical cancer screening programs. Persistent HPV infection causes most cases of cervical cancer.
To explore how Pap testing affects outcomes among women who are diagnosed with cervical cancer, researchers inSwedencollected information about 1,230 women who were diagnosed with cervical cancer between 1999 and 2001.
The main outcome of interest was how many women were “cured” of cervical cancer. This is difficult to determine at an individual level (it’s hard to say with certainty that all traces of cancer have been permanently eliminated), so the definition used by the investigators was a statistical one that looked at groups of women. Women were defined as “cured” once their risk of death dropped back down to the level of women in the general population.
- The proportion of women “cured” was 92 percent among those whose cancer had been detected by Pap testing, compared with 66 percent among those whose cancer had been detected because of symptoms.
- Among women whose cancer was detected because of symptoms, women who were up-to-date with their screening had a higher cure rate than women who were overdue for screening or unscreened.
These results provide additional evidence regarding the benefit of cervical cancer screening. Women who were screened regularly and/or had screen-detected cancer had better odds of surviving cervical cancer.
Reference: Bengt A, Andersson TML, Lambert PC et al. Screening and cervical cancer cure: population based cohort study. BMJ. Early online publication March 1, 2012.