CA125 KINETICS AS SCREENING TOOL FOR OVARIAN CANCER

(Reuters Health) - Using a risk algorithm to analyze trends in CA-125 levels identifies more ovarian cancers than waiting for levels to reach predetermined cut-off points, a new study suggests.

While the results are promising, the study's lead author said it's too soon to use the new screening method in general practice.

"Now the next question is, did we save these women's lives by picking them up earlier?" said Dr. Usha Menon of University College London.

The U.S. Preventive Services Task Force (USPSTF) recommends against screening for ovarian cancer in women using CA-125 and ultrasound, because routine screening has "no proven benefit and may lead to important harms."

Instead of using a specific threshold for high CA-125 levels, the new study, scheduled for publication in the Journal of Clinical Oncology, used an algorithm to identify worrisome serial changes in CA-125 levels.

The study followed 46,237 women who were at least 50 years old and who had annual CA-125 measurements. Based on the algorithm, the women were separated into normal, intermediate and elevated risk categories.

Normal-risk women continued with annual CA-125 blood tests. Intermediate-risk women received a repeat CA-125 screening, and elevated-risk women received a repeat screening and a transvaginal ultrasound exam.

The algorithm detected 86.5% of primary invasive epithelial ovarian/tubal cancers. Using traditional "cut-off" points of >35, >30 or >22 U/mL would have found 41.3%, 48.4% and 66.5% of the cancers, respectively.

The algorithm's sensitivity was 85.8% and its specificity was 99.8%, researchers found.

The area-under-curve for the algorithm was significantly higher than for a single threshold rule (0.915 vs 0.869; p=0.0027).

"This is an encouraging step toward what everyone hopes will be a reduction in mortality," said coauthor Dr. Steven Skates.

Until the researchers report on the number of deaths following the new screenings, there should be no change in what doctors do at this point, said Dr. Skates, who is a researcher and expert on biostatistics at Massachusetts General Hospital and Harvard Medical School in Boston.

"It might be that while we're catching cancers earlier in time, we're not catching them sufficiently early to have a reduction in mortality," he said.

Dr. Menon also told Reuters Health that data on the cost of the screening will be available later this year, after they've analyzed the number of deaths after screening.

"This is exciting in the sense that we made progress from what has gone on in the past, but we do need to see what happens in the fall or early winter to see if it's good enough," she said.

SOURCE: http://bit.ly/TwbDyp

J Clin Oncol 2015.