BC scientists first in world to decode genetic evolution of a breast cancer tumour

Vancouver, BC – Scientists in British Columbia have, in a world first, decoded all of the three billion letters in the DNA sequence of a metastatic lobular breast cancer tumour. The scientists found all of the mutations that caused the cancer to spread.

The landmark study, being be published today as the cover story in the science journal Nature, helps unlock the secrets of how cancer begins and spreads, thus pointing the way to the development of new breast cancer treatment targets and therapies.

“I never thought I would see this in my lifetime,” said Dr Samuel Aparicio, head of the breast cancer research program and research team leader at the BC Cancer Agency. “This is a watershed event in our ability to understand the causes of breast cancer and to develop personalized medicines for our patients. The number of doors that can now be opened to future research is considerable.”

Partnering with the BC Cancer Agency’s Genome Sciences Centre, Dr Aparicio’s team used the latest in next-generation DNA sequencing technology to study the evolution of a single patient’s lobular breast cancer tumour over a nine-year interval. They found 32 mutations in the metastatic cancer tumour and then looked to see how many of those same spelling mistakes were present in the original tumour. The result was surprising – only five of the 32 could have been present in all of the cells of the primary tumour, thus fingering them as the culprits that caused the disease to get started in the first place. These five mutations were previously unknown to researchers as playing a role in cancer.

“This study demonstrates the remarkable capacity of next-generation DNA sequencing technology,” says Dr Marco Marra, director, BC Cancer Agency’s Genome Sciences Centre. “The project that decoded the first human genome in 2001 took years and an enormous amount of funding. We were able sequence the breast cancer genome in weeks and at a fraction of the cost.”

Dr Aparicio was recruited in 2005 from Cambridge University, UK to develop a breast cancer research program in British Columbia at the BC Cancer Agency. He holds the Nan and Lorraine Robertson chair in breast cancer research at the University of British Columbia, the Canada Research chair in molecular oncology and is a professor in the department of pathology and laboratory medicine at UBC.

The BC Cancer Foundation founded the BC Cancer Agency’s Genome Sciences Centre, the Centre for Translational and Applied Genomics at the BC Cancer Agency, and the BC Cancer Agency’s Breast Cancer Outcomes Unit, all of which played a key role in the study. The research was conducted in the BC Cancer Agency’s research centre in Vancouver.