A large global gene study of breast cancer tissue has defined ten different subtypes of breast cancer, potentially expanding our understanding of the disease, its cause, and treatment options. It also sheds some light on the nature of triple-negative breast cancer.
In the research, published online in the journal Nature, scientists studied tissue from more than 2,000 women diagnosed with breast cancer in the past ten years. Their analysis led them to divide the tumors into at least ten different genetic variations, including:
• Seven subtypes of estrogen-positive and Her2-negative , which comprised 70 percent of all cases. These seven types differed from one another significantly, with widely varied prognoses—from 80 percent to 40 percent survival rates.
• Her2-positive, which included both estrogen-negative and estrogen-positive tumors.
• Breast cancers that are similar to those currently classified as triple-negative.
• Inflammatory breast cancer, which includes both estrogen-positive and estrogen-negative tumors, including triple-negative.
What does this mean to us? It’s hard to know at this point, but connecting some triple-negative cases to Her2-positive or inflammatory breast cancers may help us understand why some TNBC cancers are more aggressive than others. And that might eventually lead to clearer prognoses.
This is but one study, though, and it is not likely to change how breast cancer is classified at this point. But it could be an initial step toward a broader understanding of TNBC.