Cancer occurs when damaged or abnormal cells reproduce in an area, causing a tumor. It can develop into metastasis once it damages neighboring tissues. Additionally, in severe cases, it can spread to other body regions.
In many cases, breast cancer is a carcinoma, a tumor that begins in ductal (milk ducts) or lobular cells (glands in the breast that make milk). It is known as ductal or lobular carcinoma and only affects these areas, meaning, it doesn’t spread to nearby tissues.
Therefore, it is considered non-invasive cancer and is easier to treat. However, any type of cancer can still be fatal.
Invasive cancer, on the other hand, does spread to the surrounding tissues. It needs to be treated in a timely manner to prevent further damage or the transition to metastasis. It is usually more complicated to treat then.