A Comprehensive Overview of Ductal Carcinoma In Situ (DCIS)

Ductal carcinoma in situ (DCIS) is a type of breast cancer that is considered a pre-invasive or non-invasive breast cancer. This happens when healthy cells in the breast's milk ducts turn into cancerous cells. These abnormal cells start multiplying rapidly. However, this breast cancer type remains confined to the ducts, as it has not broken through the ductal basement membrane or spread to the surrounding breast tissue.

Doctors consider it an early stage of cancer and generally has a favorable prognosis if treated promptly and appropriately. If left untreated or undetected, it can potentially progress into a more serious and advanced form of breast cancer. Receiving regular breast cancer screenings and seeking medical attention if any concerning symptoms arise is important for early detection.

DCIS is classified as a stage 0 cancer as the atypical cells have not spread outside of the ducts.

DCIS makes up approximately 20% to 25% of all newly diagnosed breast cancer cases in the United States and about 17% to 34% of cases detected through mammography.

The overall incidence of DCIS has increased greatly because of the widespread adoption of mammography as a screening technique. The nature of DCIS makes it difficult to detect without screening methods, as it rarely presents with obvious or noticeable symptoms.

As DCIS is an early cancer, it often has few to no symptoms or signs. However, sometimes symptoms may present themselves such as:

• A breast lump
• Bloody nipple discharge

Since DCIS rarely shows symptoms, DCIS is normally first identified through a breast cancer screening where calcifications are observed on a mammogram by a doctor. The doctor may then recommend other tests, which could include a breast biopsy, to confirm the diagnosis.

In most cases, doctors will perform a core-needle biopsy using a hollow needle to extract tissue samples from the breast. This procedure is usually guided using ultrasound (ultrasound-guided breast biopsy) or by X-ray (stereotactic breast biopsy). During a breast biopsy, doctors take breast tissue samples, and a pathologist — a doctor specializing in analyzing body tissue and blood- examines the cells under a microscope to check for cancer.

As DCIS is non-invasive, the common treatment for DCIS would be to remove the tumor using surgery and reduce the chances of recurrence through radiation or hormone therapy (for tumors that are hormone-receptor positive). Treatment options such as chemotherapy are normally not recommended to treat DCIS. The surgical treatments usually recommended include:

• Lumpectomy (breast-preserving surgery)

A lumpectomy is a surgery that only removes the affected part of the breast together with a margin of healthy tissue that surrounds it.

• Mastectomy

A mastectomy is a surgery that removes the whole breast affected by DCIS.

The type of surgery recommended would depend on several factors, including:

• Size of the tumor relative to the size of the breast

If the tumor is large, relative to the size of breast, then a mastectomy is normally recommended.

• Number of affected areas on the breast

If DCIS affects multiple areas of the breast, a mastectomy may be more effective, especially if the area of dcis are in different parts of the breast.

• Possibility of radiation therapy after surgery

Radiation therapy is normally done after lumpectomy to reduce the chances of recurrence. If the patient cannot undergo or chooses not to have radiation therapy, a mastectomy may be recommended. A patient may not be able to get radiation therapy due to reasons such as pregnancy, prior radiation to the chest, or certain autoimmune conditions that make them sensitive to the side effects of radiation.

Radiation therapy uses high-energy rays to destroy cancer cells. It is normally used after a lumpectomy to get rid of any remaining cancer cells and reduce the chances of the cancer coming back in the same breast or nearby lymph nodes. It also reduces the chance of invasive breast cancer in either breast in the future.

For tumors that are hormone-receptor positive, hormone therapy can be considered to reduce the chances of recurrence.

Learn more: Using Medicine to Reduce Breast Cancer Risk

As DCIS is an early-stage cancer and is highly treatable, the DCIS survival rate is very high and tends not to be life threatening. The 10-year survival rate for women diagnosed with DCIS is 98%.