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Hope for ovarian cancer detection

15/01/2019 admin

Researchers have taken a small but potentially significant step closer to early detection of ovarian cancer, a sneaky disease that’s often diagnosed too late for effective treatment.

Various cancer “biomarkers” begin to show up in blood tests long before symptoms occur but aren’t accurately predictive until later, when tumours likely have reached an advanced stage, Fred Hutchinson Cancer Research Center researchers have found.

The study, published on Wednesday in the Journal of the National Cancer Institute, was headed by Garnet Anderson and Nicole Urban of the Hutchinson centre’s Division of Public Health Sciences.

“What this study did was move one step closer to early detection,” said Anderson, a biostatistician. “It gives us an idea of where we want to go but doesn’t solve the problem.”

For several years, the ovarian cancer researchers have focused on biomarkers, proteins secreted by tumours, hoping to find one or more that show up early in the disease’s progress.

Now, most ovarian cancer cases aren’t diagnosed in the early stages, when treatment has a high cure rate.

The researchers analysed stored blood samples collected over many years for a previous large research study involving women smokers.

Ultimately, 34 of those women were diagnosed with ovarian cancer. Looking at the blood samples, taken periodically up to 18 years before diagnosis, the researchers found that three of six biomarkers, including one known as CA125, increased in cancer patients up to three years before diagnosis, compared to patients without ovarian cancer.

But at that early stage, the levels weren’t high enough to accurately predict the disease, researchers found. A high degree of accuracy is required for such tests, the researchers wrote, “because a definitive diagnosis requires surgery”.

Only at a year or less before the women were diagnosed with ovarian cancer did the blood levels of the biomarkers become more accurate. While the researchers said they didn’t know whether that was sufficient time to help women live longer, a local cancer authority who was not involved in the study said any lead time may help.

“Finding ovarian cancer a year earlier could have a significant impact,” said Dr Barbara Goff, a surgeon and director of gynaecologic oncology at the University of Washington. “Even three months makes a huge difference when you’re going into someone’s belly.”

While the cancer may indeed be advanced at that point, what really makes a difference in survival time, she said, is whether a surgeon can remove all the cancer. Sometimes, “even a three-month lead time may make it easier for the surgeon to take out.”

Goff, like the researchers, said results may have been skewed by samples having been taken from smokers. “It’s unclear whether that could have altered the biologic nature of these biomarkers.”

Even so, she termed the study’s results “incredibly exciting – but very, very preliminary.”

In the US, more than 21,000 women were diagnosed with the disease last year, and nearly 15,000 died from it, according to the American Cancer Society.