Study Distinguishes Between Different Types of Breast Cancer

In a study published by Nature and sponsored by The Cancer Genome Atlas Network distinguished between four different types of cancer. The study analyzed the tumors from 825 patients making it the largest breast cancer genomics project.

Scientists were primarily researching what is thought to be the most common type of breast cancer that begins in the milk duct. They were analyzing tumors that had not yet metastasized, and from their sample size they found dramatic differences among the tumors. They found a particular type of breast cancer in which the tumor cells more closely resemble basal cells. This discovery changes the way that scientist attempt to treat this type of cancer. Rather than treat basal-like cancers with anthracyclines, this study provides evidence that it might be more efficient to use treatments for ovarian cancer—these treatments are also gentler and are not associated with heightened risk for heart damage and leukemia.

The study also found two other types of breast cancer in the luminal cells in the milk ducts. One kind is associated with a good prognosis and suggests that hormonal therapy is sufficiently effective, whereas those with the other type of luminal cancer, Luminal B might benefit from chemotherapy in addition. The research also found that certain genetic aberations were so strongly associated to each of the different types of luminal subtypes that there may be a causational relationship.

The last type of breast cancer that researchers identified is HER2-enriched. There is a drug to block the gene, Herceptin, leading to a very effective targeted therapy. However, Herceptin is associated with risks so knowing if one has HER2-enriched breast cancer helps doctors tailor treatments to the individual.

To conclude, by specifying the type of breast cancer a person has doctors are now able to better treat the cancer rather than the entire body system. This will be to the benefit of the patient who wont be victim of a chemical cocktail but instead of a targeted treatment.

NY Times:Study Divides Breast Cancer into Four Distinct Types

Nature: Comprehensive molecular portraits of human breast tumours