MicroRNA marks ovarian cancer outcome

Ovarian cancer can be hard to treat--because the disease can have non-specific symptoms, patients often only come forward when the cancer is quite advanced. Additionally, some women develop resistance to platinum chemotherapy, which is the standard treatment for ovarian cancer. A tiny variation in the KRAS oncogene may help doctors identify those women who may not respond to treatment, and predict their survival.

Researchers at Yale Cancer Centre found that women who carried the altered gene were three times more resistant to platinum chemotherapy, and postmenopausal women with the variation were more likely to die from ovarian cancer.

"This gives us a way to identify which women are at highest risk for resistance to platinum chemotherapy, the standard treatment for ovarian cancer, and helps identify ovarian cancer patients with the worst outcomes," said Joanne Weidhaas, associate professor of therapeutic radiology and senior author of the study.

The variant of the gene is not uncommon--it is seen in 12% to 15% of Caucasians and 6% of African-Americans, and in up to 25% of women newly diagnosed with ovarian cancer. The variant gene does not code for protein, but it disrupts how small RNA molecules, called microRNAs, control how other genes are expressed. It may also be associated with increased risk of breast cancer and lung cancer, and poor outcomes in colon and head and neck cancers.

Though there are few alternatives to standard chemotherapy, being able to identify the patients with this variant could help physicians manage their care, and prevent women who will not benefit from going through cycle after cycle of chemotherapy that could impact their quality of life. Targeting the variant could also offer potential new treatments for ovarian cancer and a range of other malignancies.

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