Ductal Carcinoma in Situ (DCIS) - Specialists and Information

In everyday language, most people are unfamiliar with the term DCIS. “DCIS” is the abbreviation for “ductal carcinoma in situ.” The word “carcinoma” suggests that DCIS is a form of cancer. In everyday language, doctors also refer to it as “ductal carcinoma in situ.”

DCIS is a pathological cell proliferation, i.e., a tumor. It is located in the milk ducts of the female breast. “In situ” is the Latin term indicating that something is still in its original location; in this case, the abnormal cells have not yet invaded neighboring tissue.

Important to know: Although DCIS—in situ—almost always remains in the milk ducts, it can occasionally skip a section and continue elsewhere within the ducts.

DCIS describes a precancerous condition that, if undetected and untreated, often develops into breast cancer. Early detection of DCIS during the precancerous stage offers good chances of a cure.

DCIS is a precancerous condition that, if undetected and untreated, often leads to breast cancer @ inspiring.team /AdobeStock

DCIS rarely causes symptoms. Occasionally, breast pain may occur. In some cases, a tumor may be felt during a physical exam, or there may be blood discharge from the nipple. Typically, however, affected women learn of their DCIS through a mammogram.

If DCIS is suspected, a gynecologist is the appropriate specialist for treating the tumor. They are able to distinguish DCIS from breast cancer and tailor treatment accordingly.

As a precancerous tumor, DCIS rarely forms a lump in most affected women. Consequently, it is rarely diagnosed through a physical examination. Sometimes, DCIS is discovered incidentally, for example, during the surgical removal of a benign breast tumor.

In 70 to 95 percent of cases, DCIS is accompanied by calcium deposits in the breast tissue. For this reason, doctors usually diagnose it during a routine mammogram as part of cancer screening. The calcium deposits, or microcalcifications, are clearly visible on a mammogram.

Calcifications, which often occur with DCIS, are easily detected on a mammogram @ Peakstock /AdobeStock

The next step in the diagnostic process is a biopsy. During this procedure, the doctor removes a tissue sample for examination in a histology laboratory. The examination serves to confirm the presence of DCIS and determine whether it is benign or malignant. It also clarifies whether the condition is a precancerous stage of breast cancer or breast cancer itself.

Generally, during the tissue examination, the lab determines the degree of change in the breast tissue compared to healthy tissue.

The grading scale ranges from 1 to 3:

G1 (Grade 1): low risk, with an approximately 30 percent likelihood of developing breast cancer

G2 (Grade 2): moderately increased risk of developing breast cancer

G3 (Grade 3): high risk, with a likelihood of progressing to breast cancer if left untreated

The appropriate treatment for DCIS depends on the individual clinical presentation. Key criteria include the size of the tumor and the cellular characteristics of the tumor tissue.

The primary focus is on the surgical removal of the DCIS. During the procedure, the surgeon carefully excises the DCIS from the surrounding healthy tissue, leaving a safety margin around the DCIS, so to speak. This minimizes the risk of leaving behind any overlooked tumor remnants.

If DCIS is advanced and occupies a large area, a mastectomy may be performed—even if breast cancer has not yet developed. This is followed by reconstructive surgery.

The surgical technique is similar to that used for breast cancer. However, there is one key difference: the removal of lymph nodes, which is often necessary in breast cancer surgery, is not required in DCIS surgery. Chemotherapy and radiation therapy are also not necessary. DCIS does not metastasize. Once doctors have removed the tumor or lump, the DCIS—which is classified as a precancerous condition—is considered cured.

If the histological tissue examination reveals numerous DCIS cells, doctors recommend estrogen-blocking medications after surgery. These slow the growth of newly formed DCIS cells.

Women with DCIS should undergo regular follow-up examinations even after successful treatment. In the interest of early cancer detection, these examinations should take place more frequently than standard screening exams. After all, DCIS can recur.

The causes and risk factors for DCIS have not yet been clearly defined. From a scientific perspective, this is a relatively new clinical condition. 

DCIS was first recognized in medicine only a few decades ago, since mammography has gained importance in diagnostics. Because it is a non-palpable tumor, doctors more frequently detect DCIS as an early precancerous condition. Further research is needed on the causes and risk factors for DCIS.

However, the factors that contribute to DCIS are likely to be largely the same as the causes and risk factors for breast cancer, for example:

• Heredity
• Hormonal fluctuations
• Hormone therapies
• Obesity
• Type 2 diabetes
• Lack of exercise
• Tobacco use
• Alcohol consumption

Also relevant are:

• The number of children and the woman’s age at childbirth, as well as 
• The duration of breastfeeding, and 
• Whether the woman breastfed at all

Statistically, childless women have a higher risk than mothers, and non-breastfeeding mothers have a statistically higher risk than breastfeeding mothers. 

Similarly, the age at first menstruation and the age at menopause determine the risk of breast cancer and also the risk of DCIS: The longer the period between the onset of menstruation and the onset of menopause, the lower the risk of the disease.

The risk of DCIS increases with age, which is why many women in menopause are affected @ fizkes /AdobeStock

There is no scientific evidence that tight bras, aluminum-based deodorants, abortions, or breast implants cause breast cancer or DCIS.

Following complete removal of all affected tumors and subsequent close monitoring, DCIS has a good prognosis.

DCIS is often detected during a mammogram as part of a cancer screening exam. This ductal carcinoma in situ is a precancerous condition with an excellent chance of cure—provided doctors detect and treat it in time.

If left untreated, DCIS can develop into breast cancer. The earlier surgery is performed for DCIS, the less invasive and safer the treatment process is. Patients are almost always considered cured afterward. However, they should continue to participate in regular cancer screening programs.