Cancer size and grade

Size

The size (diameter) of breast cancer is usually measured in centimetres.

Although – in general – the smaller the cancer the better, size doesn’t always give the whole picture about how fast the cancer is growing.

For example, a small cancer may grow very quickly or a larger cancer may have been growing slowly over a long time. Sometimes there may be more than one area of breast cancer. In this case, each area is measured.

Multi-centric means there is more than one area of breast cancer in different quarters of the breast.

Multi-focal means more than one area has been seen but only in one quarter of the breast.

Treatment options

You are more likely to have chemotherapy if your breast cancer is larger than 2cm (about three quarters of an inch), but this will also depend on the other results from the pathology report.

This is because larger cancers may have been there for longer before being found so may have had more chance to spread.

Grade

Cancer cells are graded according to how different they are to normal breast cells and how quickly they are growing.

In your pathology report this may be called differentiation.

There are three grades:

• grade 1 (well differentiated) cancer cells look most like normal cells and are usually slow-growing
• grade 2 (moderately differentiated) cancer cells look less like normal cells and are growing faster
• grade 3 (poorly differentiated) cells look most changed and are usually fast-growing.

With ductal carcinoma in situ (DCIS) the three grades are usually called low, intermediate and high instead of 1, 2 or 3.

Treatment options

People with grade 3 invasive breast cancers are more likely to be offered chemotherapy to help destroy any cancer cells that may have spread as a result of the cancer being faster growing.