Regular screening for Ovarian cancer does not reduce women's risk of dying from it compared to those who received usual care, according to a US study.
The randomized clinical trial of close to 80,000 women age 55 to 74 also found that some women underwent unnecessary surgery after false positives came up in either their ultrasound or blood scans.
Annual screening for ovarian cancer does not cut death rates in women at average risk "but does increase invasive medical procedures and associated harms," said the study in the Journal of the American Medical Association.
Similar rates of cancer and deaths were seen across the both groups -- 212 ovarian cancer cases and 118 deaths from it in the intervention group over 13 years of follow up.
The unscreened group saw 176 cases of ovarian cancer and 118 deaths caused by it. The difference in survival rates "was not statistically significant," the study said.
However 3,285 women received false-positive results, and 1,080 underwent surgery to have one or both ovaries removed.
Fifteen percent of these women experienced "major complications," said the study led by Saundra Buys of the University of Utah Health Sciences Center, Salt Lake City.
There may be ways to improve upon the screening, such as examining small changes in the CA-125 blood test over time, rather than by a single measure as was done in this study, the authors said.
But even the best methods for annual screening may not help when it comes to a disease like ovarian cancer, which has often spread to other organs by the time it is detected and is the fifth deadliest cancer among women.
"Evidence from modeling suggests that aggressive cancers progress rapidly through the early stages, limiting the ability to detect these cancers with yearly screening."