Breast Cancer Awareness Month: 12 different types of breast cancer – Part 1

Breast cancer is the most common type of cancer in women globally and in India. According to the World Health Organization (WHO), about 2.1 million people are diagnosed with breast cancer every year.

In India, one in every 28 women gets one of more than 12 types of breast cancer in their lifetime.

That’s right. Not all breast cancers are the same. They vary, depending on whether they are invasive (spread to surrounding areas) or non-invasive (contained in a particular area) and unifocal (a single tumour) or multifocal (multiple tumours).

Breast Cancer Awareness Month: 12 different types of breast cancer – Part 1
Representational image. Image by marijana1 from Pixabay
October is breast cancer awareness month. In the spirit of raising awareness, we bring to you a three-part series on the types of breast cancer. In the first of these articles, we look at breast cancers that typically affect women under 40 years.

Medullary breast cancer
A rare but invasive type of cancer that begins in the milk ducts (ductal carcinoma), it is so named because the affected tissues look soft and fleshy like the medulla in the brain. Medullary breast cancer accounts for only 3-5% of the total breast cancer cases and mostly affects women in their 40s and 50s. It spreads slowly but does not affect any tissue outside the breast. It has a good prognosis – there’s a good chance that it can be treated.

Paget’s disease of the breast
Paget’s disease mostly affects the skin of the areola – the dark area surrounding the nipples. To make a diagnosis, doctors look for large cells, called Paget’s cells, in the affected area. However, most patients also have one or more tumours inside their breasts. Paget’s accounts for 1-4% of all breast cancer cases. Paget’s can affect women of all ages, from young teens to those in their 80s.

Triple-negative breast cancer
Each cell in our body has receptors that link to proteins and other things to perform everyday functions.

Research shows that three different kinds of receptors fuel the growth of most breast cancers. These are estrogen receptors, progesterone receptors and HER receptors. While estrogen and progesterone are female hormones, HER-2 is a gene that produces growth proteins – cancer cells can use these proteins to grow.

None of these receptors plays a role in triple-negative breast cancer. This is a problem because this type of cancer does not respond to the most common breast cancer treatments: first, hormone therapy which suppresses the function of both estrogen and progesterone receptors, and second, drugs that target the growth protein made by the HER-2 gene.

Triple-negative breast cancer does not have any of these receptors and is hence really difficult to treat. It’s seen in 10-20% of breast cancer cases, with a higher prevalence in younger people.

This type of cancer can be really aggressive (it spreads to the nearby tissues and lymph nodes) and also has a high chance of recurrence. Treatment usually includes chemotherapy. However, removing the lump or the entire breast is often the best treatment option.

Basal-like breast cancer
This cancer gets its name from the fact that it shows up on the basal layer of the milk ducts in tests. It mostly affects younger women (below 40 years of age) and has a poor prognosis.

This type of breast cancer is often confused with triple-negative breast cancer as it often doesn’t have any of the three breast cancer receptors. However, according to the Canadian Cancer Society, not all basal-like breast cancers are triple-negative. Also, basal cell type cancer has certain changes in proteins that are not seen in triple-negative type.

Research shows that breast cancers that affect younger people tend to be of a higher grade, hormone-receptor negative and generally more aggressive. Girls who have a family history of breast cancer, or who have survived other types of cancer, should check with their doctor about the right time to start routine breast ultrasounds or MRIs.