New hope in ovarian cancer

NEW drug developments and individualised treatment are bolstering efforts to improve the prognosis for patients with epithelial ovarian cancer, say Australian experts.

Professor Martin Oehler, director of the department of gynaecological oncology at Royal Adelaide Hospital, said the past 20 years had seen little improvement in the detection and treatment of ovarian cancer, but there were now many advances in the pipeline and the research community was “very positive and hopeful”.

Professor Oehler was commenting on research published in the MJA, which he coauthored, that found a crude 5-year survival rate of 35% for women with invasive epithelial ovarian cancer. (1)

The nationwide population-based study of 1192 women diagnosed with invasive epithelial ovarian cancer in 2005 found increasing age and disease stage were most strongly associated with poorer survival.

“Our estimates confirm the ongoing poor prognosis of the disease and emphasise the need for primary and secondary prevention and better treatments for ovarian cancer to improve long-term outcomes”, the researchers wrote.

Professor Oehler told MJA InSight ovarian cancer was a “terrible disease” because by the time most women were diagnosed, the cancer was advanced.

“Once the disease has spread from the ovary to the abdomen, it’s very difficult to treat”, he said.

International research efforts were focused on early detection. Professor Oehler said although technical limitations had so far prevented the development of a blood test to detect ovarian cancer, researchers were now looking to the disease’s immune signature to aid early detection.

Oncologist Dr Anne Hamilton, of the Peter MacCallum Cancer Centre, Melbourne, told MJA InSight “the building blocks” were now starting to fall into place and new drug therapies were showing promise.

She said the Pharmaceutical Benefits Scheme listing of the antiangiogenic drug bevacizumab for patients with suboptimally debulked disease would make a modest improvement in the survival of the patients with the worst prognosis.

“We’re not expecting huge gains in the survival statistics [with this listing] but we’re hoping [it has] some impact.”

Dr Hamilton said the Australian Ovarian Cancer Study, for which she is a scientific advisor, was studying the genetic changes leading to the formation of cancers.

“[The study has] already identified subgroups of ovarian cancer and what that’s giving us now is an ability to try to tailor treatment to six different types of ovarian cancer rather than one”, she said.

Professor Oehler said personalised treatment was the future for ovarian and many other cancers.

Researchers have realised that ovarian cancer is a very heterogeneous disease consisting of distinct subtypes of different origin that vary significantly with regard to molecular biology and clinical behaviour. With this increased knowledge we are now able to develop more innovative and targeted treatments.”

Professor Oehler said that, for example, poly-ADP-ribose-polymerase (PARP) inhibitors were showing promise in the treatment of ovarian cancer in women with BCRA1 and BCRA2 mutations.

Dr Hamilton said these drugs may also prove to be effective in patients with non-hereditary cancers.

“There’s increasing evidence that many ovarian cancers have alterations in the BRCA pathways without it actually being an inherited mutation … so those cancers are still susceptible to the PARP inhibitors”, she said.

Professor Oehler said other advances in ovarian cancer treatment included the intraperitoneal delivery of chemotherapy and the development of immunotherapy. (2)

Dr Hamilton said the only prevention strategy currently available was oophorectomy for patients with BRCA1 and BCRA2 mutations.

“We only really do that for patients with the BRCA1 and BRCA2 mutations, because they run very high lifetime risks of getting ovarian cancer compared to women who don’t carry those mutations”, she said.

1. MJA 2014; 201: 283-288
2. Maturitas 2013; 77: 128-136

(Photo: Sam Ogden / Science Photo Library)