Brief overview
- Course and prognosis: Basically harmless, but possible precancerous condition.
- Symptoms: Usually no symptoms
- Causes and risk factors: Not known to date
- Diagnostics: Mammography, biopsy
- Treatment: Surgery, radiation, if necessary anti-hormonal therapy
- Prevention: Not possible with certainty
What is DCIS?
In DCIS (ductal carcinoma in situ), epithelial cells lining the milk ducts of the breast are abnormally changed. However, these cells only spread in the milk ducts (ductal), so they remain “on site” (in situ). That is, they do not (yet) invade surrounding breast tissue.
Is DCIS dangerous?
DCIS is not dangerous in itself – but it may become so in the future. This is because in 30 to 50 percent of cases, DCIS develops into an invasive (formerly: invasive-ductal) breast carcinoma, i.e. a form of breast cancer. DCIS therefore represents a precancerous stage of breast cancer.
How does DCIS manifest itself?
DCIS causes symptoms, such as pain or discharge from the breast, only in very rare cases. In most women, it is an incidental finding.
What are the causes of DCIS?
Why this possible precancerous condition occurs has not yet been scientifically clarified.
You can read more about the causes and risk factors of breast cancer in the article on breast cancer.
How is DCIS detected?
DCIS usually grows in one place in the milk ducts, but not always regularly: sometimes it skips short sections and continues to grow elsewhere in the milk ducts.
Ductal carcinoma in situ rarely forms a lump and therefore usually cannot be detected by breast palpation.
On the other hand, many DCIS patients develop so-called micro-calcifications in the breast, i.e. small calcium deposits. These can be easily detected on mammography.
To clarify whether a tissue change is DCIS or already breast cancer, the doctor takes a tissue sample (biopsy) and has it examined histologically in the laboratory.
How is DCIS treated?
The risk of breast cancer developing from DCIS is quite high. Therefore, experts recommend always having a ductal carcinoma in situ treated to be on the safe side.
Surgery
In an operation, the doctor removes the affected tissue area of the breast. In the process, he also cuts out a marginal seam of healthy tissue. This is at least two millimeters wide if radiation is subsequently administered. This is to make sure he removes all the changed cells.
If you do not want radiation, doctors will cut out the ductal carcinoma in situ with a larger safety margin, if feasible.
If possible, the doctor performs the surgery in a breast-conserving manner, meaning healthy breast tissue is preserved. In some cases, however, a breast amputation (mastectomy) is necessary, for example if the pathologically changed cells have spread too far.
In contrast to breast cancer, the altered cells of a DCIS do not (yet) spread via the lymphatic pathway to the neighboring lymph nodes (or further). Therefore, lymph nodes do not normally have to be removed during DCIS surgery.
How long patients are sick after DCIS surgery and how life becomes after DCIS immediately afterward varies from individual to individual. Ask your doctor if you are unsure.
Radiation
Doctors usually recommend radiotherapy of the entire breast after surgery. This reduces the risk of cancer recurring later.
This postoperative (adjuvant) radiation therapy is useful, for example, in relatively young patients, or if the doctor finds pathologically altered cells at the edges of the removed tissue. In such cases, the physician makes sure that the benefits of radiation are greater than the associated risks and side effects.
Anti-hormonal therapy
If the DCIS cells have many receptors for estrogen, the doctor may also administer tamoxifen after breast-conserving surgery. The active substance blocks the estrogen effect in the breast tissue and thus the growth of the altered cells.
According to current knowledge, the effect of this adjuvant (after surgery) anti-hormonal therapy is probably less than adjuvant radiation therapy of the breast.
