A Beginner’s Guide to Breast Cancer

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Let me start this with a disclaimer – I am not a medical professional. The things I’ve written here are my perspective, research and opinions. While I hope that you will find some information here useful, do not rely on this as medical advise, please confirm everything with your own doctors.

You are likely here reading this post because you have had a recent breast cancer diagnosis. Right now you are scared, confused and overwhelmed. You are likely in the middle of a whirlwind of tests and scans and you feel like you are being swept along out of control without really understanding what it going on. I know, I’ve been there!

You’ve heard this muddle of stages and grades, hormones, types of cancer, acronyms for all sorts of things – I am going to explain about each of these in basic terms and provide links to further information.


Types of Breast Cancer

I had no idea before my diagnosis that there were different types of breast cancer. The type of cancer is generally described by it’s location, whether it’s invasive, and how it’s spreading. These are the most common types, although there are other rarer types that can also occur

Ductal Carcinoma In Situ (DCIS) – This is very early breast cancer contained in the ducts. DCIS is not considered life-threatening in itself, but it may or may not become invasive at some point down the track, so it tends to be treated as though it will.

Invasive Ductal Carcinoma (IDC) – The most common form of breast cancer, accounting for about 80% of cases. This is what DCIS becomes when it breaks out of the ducts. Now it is in a form where it can spread throughout your body if not treated

Lobular Carcinoma In Situ (LCIS) – very early breast cancer that is contained in the lobules and not yet invasive. It is again treated as though it will become invasive.

Invasive Lobular Carcinoma (ILC) – This is when the cancer cells have broken out of the lobules and are now invasive and could spread to other parts of the body.

Pagets Disease of the Nipple – This cancer grows in the nipple itself and is generally found when the nipples become itchy and irritated.

Inflammatory Breast Cancer – this cancer affects the blood vessels in the skin and the lymphatic system in the breast. It causes the breast to become red and inflamed. It is very rare.

Metastatic Cancer – this is when the initial cancer has now spread beyond the breast to other parts of the body. 


Learn more about the types of breast cancer here 


Stages of Breast Cancer

Stages of cancer are generally based on the size of the tumour and how far it has spread. Often a final stage is not given until after surgery, although one may be suggested earlier based on scans.

There are generally thought to be five stages of breast cancer. Declaration of one stage or another tends to be a little subjective and many things are taken into consideration by the doctors, including the grade, ER/PR/HER2 status and Oncotype score. The below descriptions are fairly general and may be slightly different to your diagnosis when everything is considered

Stage 0 – this is used for non-invasive breast cancer, such as DCIS and LCIS

Stage 1 – A small, invasive tumour, less than 2cm, that has not spread outside the breast

Stage 2 – A tumour between 2-5cm, and/or there has been 1-3 lymph nodes involved

Stage 3 – A tumour larger than 5cm and/or spread to 4-9 lymph nodes

Stage 4 – Cancer has spread beyond the breast to other organs such as skin, bones, lungs etc.


Read more about the stages of cancer, including many of the variations, here 


Grades of Breast Cancer

The grade of breast cancer tells you how quickly the cancer cells are growing and spreading. This can dictate the type of treatment recommended.

Grade One – the cancer is growing slowly

Grade Two – the cancer is growing somewhat quickly

Grade Three – the cancer is aggressive and growing quickly. 


Read more about the grades of breast cancer here 


What “Feeds” Your Cancer

The elements that feed your cancer determine how it is treated. Here are the different types

ER/PR+ – this refers to cancers that are fed by the hormones oestrogen and progesterone. This is the most common type of breast cancer. Sometimes only one hormone will be positive, sometimes both, but treatment seems to be mostly the same. If you have hormone positive cancer you will likely take some form of hormone blocker for 5-10 years after your other treatments have finished. Read more here 

HER2+ – this stands for “human epidermal growth factor receptor 2” a gene that can have an effect on breast cancer. HER2+ cancers are considered to be more aggressive that hormone driven cancer. But if you are positive for the gene, there are some specific treatments that can target your cancer, so outcomes are good. Read more here 

TNBC – triple negative breast cancer occurs when the tests for hormone receptors and HER2 all come back negative. TNBC tends to be more aggressive and is often found in younger women. Treatment is different to the other types, and no hormone blockers are required.  Read more here 


I hope this all helps you to understand a little better all the numbers and letters your doctors gave you. Understanding the different terms and what they mean will hep you make the right treatment decisions for you. Remember though that everyone’s diagnosis is slightly different and treatment usually depends on a combination of everything here and even more factors, such as age, recurrence rates and other medical conditions.


Want to read more of my story? Here are some of the key posts

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A beginner's guide to breast cancer, explaining all those confusing terms the doctors tell us during our diagnosis | #breastcancer #diagnosis

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