Ovarian cancer molecular updates

By Dr. Ananya Mandal, MDJul 1 2011

Gene mutations linked to ovarian cancer

In a new study a genetic mutation was found in the most common form of ovarian cancer. This according to the US scientists could pave the way for a more effective treatment of the disease. The detailed genetic map already helped scientists identify existing drugs with the potential for treating the mutations found in ovarian cancer tumors and also identified mutations that could respond to new drugs.

The study, published Wednesday in the journal Nature, will contribute to a more targeted approach to the cancer because doctors will be able to treat patients according to the genetic mutations that drive the growth and spread of their tumors. Scientists hope that the Cancer Genome Atlas project findings will allow them to understand how some genes cause cancer and develop drugs that control them.

Francis Collins - the director of the U.S. National Institutes of Health, in Bethesda, Md., which funded the research - said “this landmark study is producing impressive insights into the biology of this type of cancer. It will significantly empower the cancer research community to make additional discoveries that will help us treat women with this deadly disease.”

The team analyzed 316 ovarian tumors and found that the gene TP53 was present in 96 percent of the cancers. The study also found 108 genes linked to poor survival and 85 genes associated with better survival.

Ovarian cancer is the fourth most common cause of female cancer deaths in the U.S. and kills nearly 14,000 women in the country each year.

NCI Director Harold E. Varmus, M.D said, “The new knowledge of the genomic changes in ovarian cancer has revealed that the molecular catalysts of this disease are not limited to small changes affecting individual genes. Cancer researchers can use this comprehensive body of information to better understand the biology of ovarian cancer and improve the diagnosis and treatment of this dreaded disease.”

Ovarian cancer resistance to chemotherapy lies deep within

Scientists at the charity Ovarian Cancer Action have found out the reason why some people have ovarian cancer that is resistant to conventional chemotherapy. Rather than the cancers developing immunity, they found that minute traces of cancers that were always resistant to platinum therapy were there from the beginning and could be due to underlying differences.

This discovery has helped them identify four or five different molecular “targets” that could be the focus of new drugs, said Prof Hani Gabra, director of the charity's research centre. He explained, “These cancers look like they are platinum-resistant, but in fact they were there from the outset and they were never touched by the drugs.” Unaffected, they had simply taken their time to grow he said.

One of the targets was a gene called STAT1 that was “very active” in cells platinum-resistant cancer cells. They also found that an enzyme, called HDAC4, spurred it into action. Sometimes genes and enzymes have already been studied for their role in different diseases.

The most exciting aspect, said Prof Gabra, was that a couple of these targets had already been studied and that drugs were consequently already in development. This eliminated the need for very early-stage research. He added, “All we've got to do is put these drugs together with platinum treatment in a trial in people. We are hoping to do proof of concept trials this year or next year.” The study is published this month in the journal Cancer Research.