THE GRH BREAST CARE WEB SITE Types of Breast Cancer There are two main categories of breast cancer(carcinoma) -invasive carcinoma and non-invasive carcinoma. Non-invasive carcinoma (carcinoma in situ) This means there are cancer cells in your breast tissue that are growing and dividing abnormally. They are confined to the breast ducts (milk ducts) in the breast and have not developed the ability to spread either within or outside the breast. Some doctors may describe it to you as a non-invasive (non-spreading) cancer while other may call it a pre-cancerous condition. Invasive carcinoma This is what is generally meant by the term 'breast cancer'. Most invasive cancers are called 'invasive cancers of no special type'. With invasive cancer, the cells have developed the potential to live outside their place of origin and spread to other parts of the body. The potential for the tumour to spread can be measured and is known as 'grading'. Breast cancer spreads by cells invading either the lymphatic or blood vessels in the breast and being carried through them to other areas of the body where they form other tumours called metastases. It is this that makes the disease more serious. The potential for spread doesn't necessarily mean that it has happened, but treatment decisions are usually based on an assessment of the extent of or risk of spread. This section is an extract from "Treating breast cancer" one of Breast Cancer Care booklets and is used with permission. For further details go to www.breastcancercare.org.uk Homepage