Your breast specialist needs certain information about the DCIS to help plan the best treatment for you. This includes:
- the stage of the cancer
- the grade of the cancer
- whether the cancer has certain hormone receptors (see below).
The stage of a cancer describes its size and whether it has spread from where it started.
DCIS is described as stage 0. This is the earliest stage and means there is no invasive breast cancer. DCIS can be any size, but will always be stage 0.
The grade of a cancer describes how the cells look and how quickly they grow compared with normal cells. In DCIS, the grade of the cells is important. It indicates how likely DCIS is to come back in the breast. It also indicates how likely it is to develop into an invasive cancer.
There are three grades:
Grade 1 (low-grade cancer)
The cancer cells look similar to normal cells (they are well differentiated). They usually grow slowly. These cancer cells are less likely to spread.
Grade 2 (moderate or intermediate-grade cancer)
The cancer cells look more abnormal and grow slightly faster than grade 1 cells.
Grade 3 (high-grade cancer)
The cancer cells look very different from normal cells (they are poorly differentiated). They may grow more quickly than grade 1 or 2 cells.
The pathologist will examine the tissue to see whether the cells have started to spread through the walls of the lobules or ducts. These very small areas of spread are called areas of microinvasion.
DCIS cells may have receptors (proteins) on them that allow hormones, such as oestrogen, to attach to the cancer cell. These hormones can help the cancer cells grow. A pathologist tests the tissue that was removed during the biopsy or surgery for oestrogen receptors.
Drugs that reduce levels of oestrogen in the body are called hormonal therapies. If the DCIS is oestrogen receptor-positive (ER-positive), your doctor may suggest taking hormonal therapies to shrink the DCIS before surgery.