A new trial drug that has demonstrated some success against ovarian cancer caused by mutations in the BRCA1 or BRCA2 genes may also be effective against more common forms of ovarian cancer not caused by those gene mutations.

The drug, olaparib, blocks the activity of a protein called poly ADP ribose polymerase (PARP). Both PARP and BRCA proteins are involved in DNA repair. Clinical trials of olaparib in patients with BRCA 1 and 2 mutations have yielded encouraging results, say researchers.

In the new study, olaparib reduced the tumor size in patients with non-hereditary or sporadic ovarian cancer, which is much more common than BRCA-mutated ovarian cancers.

The study included 65 ovarian cancer patients who received 400 milligrams of olaparib twice daily for four weeks. Tumor shrinkage was seen in 41 percent of patients with BRCA mutations and in 24 percent of those without BRCA mutations. Side effects were described as mild and included fatigue, nausea, vomiting and decreased appetite.

"This finding not only suggests new therapeutic possibilities for women with this aggressive type of ovarian cancer, but also importantly confirms the hypothesis that subpopulations of patients with common sporadic tumors can be targeted effectively with PARP inhibitor therapy," said Dr. Melinda Telli, of Stanford University School of Medicine.

While the study is not recruiting participants at this time, more information about the research can be found at ClinicalTrials.gov, number NCT00679783.

Learn more about Ovarian Cancer

The American Cancer Society outlines the risk factors for ovarian cancer.

Sources: U.S. Department of Health and Human Services

The Lancet