Breast cancer breakthrough could take 4 years to test
Published Thursday, April 5, 2012 8:44AM EDT
It could take up to four years before a scientific breakthrough is proven in clinical trials, said the lead author of a new study into "triple negative" breast cancer.
University of British Columbia scientist Dr. Sam Aparicio was part of the research team that mapped the genome sequences of tumours from more than 100 patients with the cancer, so named for the three cancer-causing proteins that it's missing: the estrogen, progesterone and ERBB2 receptors.
These tumours do not respond to drugs that target hormones, such as Tamoxifen or Femara, or to Herceptin, which targets the HER2 receptors. This type of cancer accounts for 16 per cent of all breast cancer cases and about 25 per cent of breast cancer deaths.
The scientists found the disease isn't just one form of cancer, but one with many mutations that share one common factor.
"The patients' tumours varied enormously in their genetic makeups," Aparicio, who is also the chair of breast cancer research at the BC Cancer Agency, explained Thursday on Canada AM.
Recognizing that they all weren't one "uniform subtype" was a surprise and a major breakthrough, he said.
"It's actually extremely complex, with each cancer at a different stage in the evolutionary process at the time of diagnosis, which helps to explain why patient responses to treatment differ greatly," the doctor explained in a statement released Wednesday.
The researchers compare the genetic sequence to a "mini ecosystem" with many differences from person to person. The variety in the cancers' composition is what makes generalized therapies ineffective.
Researchers hope their finding will help doctors cater treatment to each individual patient.
About 15 to 20 per cect of those with "triple negative" cancer have an "actionable mutation," explained Aparicio during his Canada AM appearance. That means those tumours may respond to an experimental therapy currently in existence, or a treatment that has been proven for another form of cancer.
The findings provide a "roadmap" that will guide the researchers' study into those treatments, he said.
The study included research teams from the University of British Columbia, Cross Cancer Institute of Alberta and Cancer Research UK/University of Cambridge. Their findings were published Wednesday in the online edition of the journal Nature.