Luminal A Breast Cancer

More and more, researchers and physicians are categorizing breast cancers by their gene expression, or how the cancer appears on a molecular level, to better guide treatment. “Luminal A” is one of five main breast cancer subtypes based on this genetic criteria.

Breast cancers classified as luminal A are:

  • Progesterone-receptor (PR) and/or estrogen-receptor (ER) positive
  • Human epidermal growth factor receptor-2 (HER2) negative
  • Low in the Ki-67 protein, which influences how fast cancer cells grow

About 73% of breast cancer cases in the United States are classified as luminal A, according to the American Cancer Society.

Luminal A Breast Cancer Causes

The exact cause of luminal A breast cancer—and cancer in general—is not fully understood. But, researchers have identified multiple risk factors that can increase a person’s likelihood of developing breast cancer, including luminal A breast cancers. These involve:

  • Being older than 50
  • Having a family history of breast or ovarian cancer
  • Having dense breast tissue
  • Previously undergoing radiation therapy treatment to the chest
  • Drinking alcohol
  • Being overweight or obese
  • Having your first child after age 30 or never carrying a child

Luminal A Breast Cancer Symptoms

Most breast cancers present as a hard or rubbery breast lump. This lump may feel like it is immovable and fixed into the breast tissue. Other common breast cancer symptoms include:

  • Changes in breast skin, such as reddening, dimpling, swelling or thickening
  • Nipple discharge that is not breastmilk
  • Changes in the appearance of one or both nipples
  • Abnormal pain in one or both breasts

Luminal A Breast Cancer Diagnosis

Diagnosing luminal A breast cancer is similar to diagnosing other molecular subtypes. If signs of cancer are identified, an imaging test such as an ultrasound or mammogram can be used to view images of breast tissue. If further testing is needed, a biopsy to remove a lump or small amount of breast tissue for testing may be performed to make a conclusive diagnosis.

Luminal A Breast Cancer Treatments

Tampa General Hospital’s Cancer Institute is helping patients with luminal A breast cancer achieve positive outcomes. Breast cancer treatment plans will vary according to multiple factors, such as the patient’s age, overall health and treatment preferences, as well as the stage of his or her cancer. Generally speaking, luminal A breast cancer tends to respond well to hormone therapies and chemotherapy.