Staging and grading DCIS

Your breast specialist needs certain information about the DCIS to help plan the best treatment for you. This includes information about the stage and grade of the cancer and whether it has certain hormone receptors.


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 shows how likely DCIS is to come back in the breast, or to develop into an invasive cancer. There are three grades:

  • Low-grade DCIS – the cells look similar to normal breast cells and usually grow slowly. The cancer cells are less likely to spread into surrounding tissue.
  • Moderate- or intermediate-grade DCIS – the cells look more abnormal and grow slightly faster than low-grade DCIS.
  • High-grade DCIS – the cells look quite different from normal breast cells and grow more quickly.

High-grade DCIS is more likely to come back or develop into an invasive cancer than low-grade DCIS. Low-grade DCIS can still develop into invasive cancer, but this would usually take many more years than for a high-grade DCIS.

Knowing the grade of the DCIS helps your doctors decide on the best treatment for you.

DCIS with microinvasion

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.

Hormone receptors

DCIS cells may have receptors on them that allow hormones, such as oestrogen, to attach to the cancer cell. These hormones can help the cancer cells to grow. The tissue that is removed at surgery is tested for oestrogen receptors.

If DCIS is oestrogen-receptor positive (ER-positive), your doctor may talk to you about hormonal therapy treatment. However, hormonal therapy isn’t standard treatment for DCIS.

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Most women will have surgery to remove the cancer. You may also have other treatments to reduce the risk of it coming back.