Breast cancer is not a single disease, but instead has four molecular subtypes, according to a recent research. Each of this subtype had different treatment reactions and different mortality rates. The incidence of these subtypes differs by age, race, ethnicity and many other factors.
Researchers from the American Cancer Society, the Centers for Disease Control and Prevention (CDC), the North American Association of Cancer Registries (NAACCR), and the National Cancer Institute (NCI) have categorized breast cancers according to tumor subtypes, which is vital for the treatment of the disease.
Betsy A. Kohler, one of the members of the study and researcher at the NAACCR said, “Defining breast cancer by the four subtypes will aid breast cancer diagnosis and treatment and help patients better understand how their diagnosis will affect their health.”
The researchers scrutinized the frequency of invasive breast cancer among women aged 85 and younger by utilizing data from NAACCR member archives for their study. These registries contain records of breast cancer incidence by four tumor subtypes, defined by the hormone receptor (HR) status and the expression of the HER2 gene. The subtypes are: Luminal A (HR+/HER2-), Luminal B (HR+/HER2+), HER2-enriched (HR-/HER2+) and triple-negative (HR-/HER2-).
The researchers found that the foremost aggressive carcinoma subtype, HR-/HER2-, was prevalent among non-Hispanic black women. They also discovered that non-Hispanic black women also had the maximum rate of late-stage breast cancer verdict thru all subtypes, besides the highest rates of poorly, undifferentiated pathology. Researchers concluded this elucidates why non-Hispanic black women have the highest incidence of breast cancer fatalities.
Dr. Harold Varmus, Director of the NCI said, “The fact this report assesses breast cancer as four molecularly defined subtypes, not a single disease is a welcome step, depending on the medically important information that already guides therapeutic strategies for these subtypes. The new diagnostic categories now being defined will increasingly support our ability to prevent and treat breast and many other kinds of cancer, as well as monitor their incidence and outcomes more rigorous over time.”
The Journal of the National Cancer Institute published the findings.