The discovery that breast cancer cells mutate as the disease progresses is an important finding that may lead to new treatments, researchers say.
They analyzed the DNA of healthy cells and cancer cells at three different stages of breast cancer in one patient. Nine years after her initial diagnosis, the woman's cancer had spread (metastasized) to other parts of her body. There were 32 DNA mutations in the metastasized cells.
"When we looked back to see if (the mutations) were present in the primary tumor, we found only five mutations that could have been present in all cells," lead researcher Samuel Aparicio of the British Columbia Cancer Agency in Canada, told Agence France Presse.
"This is a watershed event in our ability to understand the causes of breast cancer and to develop personalized medicines for our patients," he said in a news release.
The findings "will lead to a shift in perspective" in how cancer is treated, he told AFP.
The study appears in the Oct. 8 issue of the journal Nature.