What is DCIS breast cancer?

DCIS is a non-invasive (or pre-invasive) form of breast cancer where abnormal cells are confined to the milk ducts and have not yet invaded surrounding breast tissue. It is considered stage 0 breast cancer and is often detected via mammography as microcalcifications.

Why does DCIS matter?

While DCIS itself is not life-threatening, it has the potential to progress to invasive breast cancer if left untreated or recur as with invasive or pre invasive disease. The key challenge in managing DCIS is determining which cases are likely to remain indolent versus those that may become aggressive over time.

How is DCIS treated?

Most patients undergo breast-conserving surgery (lumpectomy) or, in some cases, mastectomy, depending on the size, extent, and patient preference. 

Radiation therapy (aka radiotherapy): Often recommended after lumpectomy to reduce the risk of recurrence, particularly for higher-grade DCIS. Radiation about halves the risk of a recurrence in the breast. 

If the DCIS is oestrogen-receptor-positive (ER+), hormone-blocking therapy (e.g., tamoxifen or aromatase inhibitors) may be recommended to lower recurrence risk. This is particularly important if there is a family history of breast cancer or an increased genetic risk. 

What is the prognosis?

The prognosis for DCIS is excellent, with a nearly 100% survival rate when treated appropriately. However, the goal of ongoing research is to refine treatment strategies to avoid overtreatment while ensuring cancer does not progress.

Emerging approaches, such as active surveillance for low-risk DCIS, are being investigated, but for now, individualized treatment decisions remain the cornerstone of DCIS management.