Categories: Breast Cancer

Molecular Classification of Breast Cancer: A New Way of Treatment

Breast cancer is the most common type of cancer in women. It’s also the second most common cancer overall. In recent years, there have been many innovations in breast cancer treatment. As a result, there are new avenues in understanding and treating breast cancer far more effectively.  One such innovation is the molecular classification of breast cancer. Let’s delve deeper into it.

As a heterogeneous disease, breast cancer comprises of several molecular and genetic subtypes.  Earlier, the classification of tumours was done morphologically. With the advent of molecular classification, the method of classification is highly improved.

Compared with molecular classification, the existing method of histological classification systems for breast cancer is clearly at a disadvantage. Here’s why:

  • Histological classification systems for breast cancer lack accuracy in predicting the prognosis or selecting the appropriate treatment.
  • On the other hand, molecular classification can be more accurate and powerful as a predictive factor for the treatments.

As a result, molecular classification considerably reduces the use of chemotherapy and has an advantage in reducing toxicity and costs.

Having seen the advantages of molecular classification of breast cancer, let’s now move on to the molecular subtypes of breast cancer.

Molecular subtypes of breast cancer:

Chiefly, there are five molecular subtypes of breast cancer. These are based on cancer expresses.

  • Luminal A: Breast cancer that falls into this category are characterized by the following features:
  1. It is hormone-receptor positive i.e. estrogen-receptor and / or progesterone-receptor
  2. It is HER2 negative
  3. It has low levels of the protein Ki-67
  4. Cancers of this type are usually low-grade, likely to grow slowly and have the best prognosis
  • Luminal B: It has a lot in common with Luminal cancer and certain characteristics of its own:
  1. It is hormone-receptor positive i.e. estrogen-receptor and / or progesterone-receptor
  2. It can be HER2 positive or HER2 negative
  3. It has high levels of Ki-67
  4. Unlike Luminal A cancers, Luminal B cancers grow faster and their prognosis is slightly worse
  • Triple-negative / basal-like:
  1. It is hormone-receptor negative i.e. estrogen-receptor and / or progesterone-receptor
  2. It is HER2 negative
  3. This type of cancer is more common in women with BRCA1 gene mutations
  4. Though researchers are yet to find out the reason, triple-negative/basal-like breast cancer is more common among younger women and Afro-American women
  • HER2-enriched:
  1. This cancer is hormone-receptor negative i.e. estrogen-receptor and / or progesterone-receptor
  2. This is HER2 positive
  3. It tends to grow faster than luminal cancers and has a worse prognosis
  4. Can be treated successfully with targeted therapies aimed at the HER2 protein
  • Normal-like:
  1. It has a lot of similarity with luminal A cancer
  2. It is hormone-receptor positive i.e. estrogen-receptor and / or progesterone-receptor
  3. It’s HER2 negative.
  4. It has low levels of the protein Ki-67
  5. When it comes to prognosis, it fares slightly worse than luminal A cancer’s prognosis

While it’s great that new ways of treating breast cancer are emerging rapidly, the key to keeping breast cancer under control is breast self-examination, periodical check-ups, and early detection. Let’s make sure that we spread the message without fail.

Dr. Akshita Singh, Consultant – Breast Cancer, Oncology | Mazumdar Shaw Medical Center, Bommasandra

Narayana Health

Recent Posts

Minimally Invasive Spine Surgery (MISS) and Endoscopic Spine Surgery (ESS)

Minimally invasive spine surgery (MISS) is a way of performing spinal surgery on the bones…

17 hours ago

Bronchiolitis

What is bronchiolitis? Bronchiolitis is an infection of the lungs which affects tiny branching tubes…

2 days ago

TONGUE TIE

TONGUE TIE RELEASE: Tongue-tie, also called Ankyloglossia, implies that the undersurface of the tongue is…

3 days ago

All you need to know about resting heart rate

Resting heart rate, as the phrase suggests, indicates the number of times your heart beats…

3 days ago

All you need to know about blood pressure

Let’s Talk About Blood Pressure Blood pressure or BP is so common that one in…

4 days ago

All About Body Mass Index (BMI)

Body Mass Index or BMI is no stranger term to you. You’ve come across it…

5 days ago