Scientists in Vancouver have found seven new subtypes of ovarian cancer based on genetic changes, a finding that can help guide treatment and new drug discovery.

“We use an entire pattern of alterations in the genome and can read the genomes of these cancers and the mutations reflect the changes in these cancers,” Dr. Sohrab Shah, who led the research, said in a telephone interview with CTV News.

“It helps us understand the processes in the development of the cancer…like a forensics of the biology,” said Dr. Shah, a senior scientist at the BC Cancer Agency.

The discovery, published in Nature Genetics, analyzed the genetic information of more than 100 ovarian cancer patients in order to identify abnormalities in the DNA of ovarian cancer cells.

Seven cancer subtypes were discovered. Two belong to a very common and deadly form of ovarian cancer called high grade serous carcinoma (HGSC).

Scientists think the structural changes in the cancer DNA can identify which patients won’t respond to current chemotherapy. And when a test becomes available, it will spare women from “futile and toxic therapy.”

The DNA changes may also help scientists design and test new experimental medications.

“This study demonstrates that patterns of changes across the DNA inside cancer cells can help direct drug development efforts for the hardest-to-treat subtypes of ovarian cancer,” said Dr. Shah.

The other five subtypes uncovered were found by analyzing clear cell, endometriod and adult granulosa cell ovarian cancers. The results from this work suggest that some of these subtypes may be susceptible to existing treatments.

Scientists are now moving forward, trying to turn the DNA patterns discovered into tests that could be used by doctors, in a bid to separate those who will respond to current treatments and those who need to try experimental therapies.