A comprehensive analysis of eight clinical trials and four cohort studies on diagnostics researchers cervical cancer from UC Davis and Kaiser Permanente Northwest showed that, although pap smears are still very effective for detecting pre-cancerous cells, testing for the virus that causes cancer and is an excellent screening tool.
The findings, published August 21 in the Journal of the American Medical Association (JAMA), have been used to inform the Task Force on the United States Preventive Services, which published its updated recommendations for the diagnosis of cervical cancer in the same issue of the journal. The Task Force is an independent group of experts that provides evidence-based recommendations for the prevention of diseases. The Task Force also submit an annual report to Congress on the basis of actual clinical preventive services and recommends the priority areas which deserve further study.
The study was conducted Melnikov Joy (Joy Melnikow), director of the Center for Medicine and Research, UC Davis, a doctor of family and community medicine and an expert in the field of screening on the basis of evidence.
A systematic review, it was found that in the first test diagnostics of viral types HPV high-risk human (HPV) continuously detects a higher frequency change precancerous cells compared with Pap smear, also referred to cytology, which detects premalignant cells and cancer cells. It is also found that high risk HPV testing were associated with higher false positives and subsequent testing than screening with the Pap smear.
High risk HPV, a virus that spreads through sexual contact, causes 90% of cervical cancer. For most women, HPV infections resolve spontaneously, but in some cases the virus persists and can lead to cervical cancer in the end.
Melnikov and her colleagues studied the study of high-risk HPV testing alone or in combination with a Pap smear. All studies were conducted in organized screening programs, in which women were invited to be screened at regular intervals.
In a systematic review considered both benefits and harms of screening for cervical cancer for high-risk HPV. The advantages include the discovery of invasive cervical cancer or to cancer (cervical intraepithelial neoplasia, CIN). They also searched rates of false-positive test results, colposcopy rate (the test was carried out if the test for the presence of abnormal Pap test), biopsy and any related psychological harm.
Melnikov said that in the current analysis of data on the analysis of Pap smears do not specifically analyzed, also called cytology, as in previous surveys found evidence that the method is safe and effective.
Analysis showed that the use of highly efficient HPV test, which was used alone, resulted in a statistically significant increase in the detection of abnormal cells strongly or CIN3 + compared to cytology in the first round of screening. Joint Research testing found no statistical increase detection CIN3 +.
"Our work has demonstrated that there is now compelling evidence of efficacy testing of high-risk HPV, used as a test for cervical cancer screening," - said Melnikov. "We also found that both HPV screening strategies were higher false-positive rates and colposcopic than Pap smears. These false alarms can cause more harm to the potential treatment. "
"We found that regular screening by any method will lead to a reduction in the frequency of cervical cancer," - said Melnikov. "In the US, where the majority of women are not part of an organized program of diagnostics, our biggest problem is the coverage of women who did not pass the examination."