New Discovery - Leap Forward in Breast Cancer Research

In a world first, Canadian scientists have decoded all three billion letters of DNA in a breast cancer tumour and identified the mutations that caused the cancer to spread. The landmark study by researchers at the B.C. Cancer Agency is a first step towards unlocking the secrets of how cancer begins and moves to other parts of the body. Principal investigator Dr. Samuel Aparicio says the discovery should help researchers develop new breast cancer treatments based on the mutated genes. Aparicio says the work is another major step towards personalized medicine. Co-author Dr. Marco Marra says new-generation technology allowed the researchers to decode the breast cancer DNA in just weeks and at a fraction of what it would have cost only a few years ago.

Not all cells in a breast cancer tumour contain the same mutations, researchers in British Columbia have found. The finding that changes occur in tumours over time could change how scientists think about developing new breast cancer drugs and deciding which patients would benefit most from treatments.
In Wednesday's issue of the journal Nature, Samuel Aparicio and his colleagues at the BC Cancer Agency charted the genetic mutations that occurred in the 3 billion letters of the DNA sequence from an estrogen-receptor-alpha-positive breast tumour.
"The impact is going to be in the way that cancer researchers look at developing therapies and applying therapies." said Aparicio, chair of breast cancer research at the BC Cancer Agency and Canada research chair in molecular oncology.
"Over the long term, we hope that being able to decode the sequence of tumours on a routine basis will eventually lead us to being able to better predict which combinations of medicines to use when treating a cancer. We're not quite at that point yet."

Historically, it has been assumed that tumours are uniform, with the same mutations found in all tumour cells. But only five of the mutations were found in all of the tumour cells, which showed not all cells in a tumour contained the same mutations. It's now thought that these differences may help explain why some tumours resist treatment, Aparicio said. The team hopes their findings will help pinpoint which mutations make cells resistant to therapy and reveal which drugs are most effective for a patient's cancer.

They are steadily breaking down the walls sisters. Just hang in there. A happy ending to this story is just around the corner.