What is breast cancer?

Breast cancer is the most common cancer in women. It is a disease where malicious cancer cells forms in the tissue of the breast.


There are many different kinds of breast cancer. Overall they can be divided into two main groups. Invasive and non-invasive. Non-invasive cancers are the ones that stay where they started – in the breast. The invasive cancers however will spread to anywhere they can get. Unfortunately most cases of breast cancer are invasive types. Defining which type of breast cancer you have is vital in deciding which treatment is necessary.

Definition of breast cancer

Cancer occurs when the genes responsible for the growth and health of cells mutate. Normally the cells replace themselves through cell growth. Unfortunately the mutations are able to control the cells and can shut down production of certain genes and increase production of others in the affected cells. Once the cells have been manipulated, they don't know right from wrong and will keep dividing out of control and produce more cells like themselves, eventually forming a tumor. Over time, the cancer cells can spread to healthy breast tissue and sometimes it manages to spread to the underarm, where lymph nodes can be found. Lymph nodes are little « cleaning organs » that help get rid of foreign substances in the body and they are well connected to the rest of the body. So when the cancer cells spread to the lymph nodes, it becomes possible for the cancer to infiltrate other areas of the body.

There are many stages of breast cancer and it can spread over time. Therefore it is important to diagnose it as soon as possible, to start treatment and avoid spreading. The more it spreads, the more difficult it is to remove. The stages are determined by the size of the tumor, the number of lymph nodes affected and on signs showing if other parts of the body have been affected. Stage 0 is the least invasive level and stage 4 is the most invasive, showing that the cancer has spread to other parts of the body.

Last updated: 10/3/18

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Author: Carenity Editorial Team, Editorial Team

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