Screening for Ovarian Cancers Proves Inconclusive
The results of a recent study regarding screening tests for ovarian cancers is questioning the effectiveness of the procedure, the main concern being the fact that, at an early stage of development, the biology of ovarian cancers often interprets them as being slower growing and less likely to spread than more aggressive cancers, which are typically discovered in an advanced stage.
The research, led by Dr. Andrew Berchuck, a gynecologic oncologist at the Duke Comprehensive Cancer Center, consisted in the examination of gene expression patterns in 166 ovarian cancer tissue samples, both from patients who had experienced long-term survival of over seven years and from patients who had died within three years of diagnosis. Using micro-arrays to examine over 22,000 probes of DNA, genes that were most predictive of survival were identified.
Regarding the outcome of the research, Berchuck stated:
“We found that certain patterns predicted long-term survival and others predicted a poorer prognosis in advanced stage cases. Cancers that were detected at an early stage almost always shared gene expression characteristics with advanced stage cases that were long-term survivors, suggesting a shared favorable biology. Our study showed that the ovarian cancers currently detected at an early stage have gene expression profiles that correlate with favorable outcome, rather than being representative of the entire spectrum of disease aggressiveness.
While these results could be seen as discouraging, it must be remembered that this information is an important piece of the ovarian cancer puzzle, and data like these that increase our understanding of the disease hopefully will eventually lead to breakthroughs in prevention, early detection and treatment of this deadly disease.”
Similar challenges are seen in the screenings of lung cancer and prostate cancer, where the method detects the disease using radiological imaging and/or blood markers but lets unclear if cancer-related deaths are prevented because screening preferentially detects more benign cancers that are much less likely to be fatal. No ovarian cancer screening test is yet approved, CA125 blood test and transvaginal ultrasound imaging currently being evaluated in clinical trials.
Adapted from materials provided by Duke University Medical Center.
