In a wide-ranging new study, researchers have classified breast cancer into 10 different subtypes — a finding that could change the future of breast cancer diagnoses, treatment and survival.

The research team known as the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) analyzed the genetic makeup of 997 breast tumors from nearly 2,000 women from the U.K. and Canada who were diagnosed five to 10 years ago. The researchers extensively monitored the genetic details of the tumor samples — looking not only at gene mutations, but also at their specific activity — and compared the findings to the women’s age at diagnosis and their long-term survival rates.

 

By the end of the study, which took some five years to complete, the researchers had identified 10 classifications of tumors, based on their genetic fingerprints. The researchers then confirmed the validity of those categories by testing them in a separate group of 995 breast cancer tumors.

The new categories range from very treatable to extremely aggressive. While much further study is needed to figure out whether the classification system will benefit patients with cancer in the real world, the new findings are a remarkable step forward in the understanding of how breast cancer develops and progresses.