6 Risk Factors for Ductal Carcinoma In Situ (DCIS) Progressing to Breast Cancer

Results of a new study provide valuable information about how women diagnosed with ductal carcinoma in situ (DCIS) should be treated. A systematic review summarizing current knowledge about factors posing a risk for breast cancer after a DCIS diagnosis formed this meta-analysis. Among 26 factors, 6 were found to increase the risk of DCIS progressing to breast cancer by between % 36 and % 84.

These 6 factors are;

1. Race (African ancestry),
2. Premenopausal status (not yet having reached menopause), 
3. A palpable lump, 
4. Positive surgical margins, 
5. High histological grade and 
6. High p16 protein expression (overexpression/production).

The study also identified biases that frequently arise in research on breast cancer development after a DCIS diagnosis. The study by Visser and colleagues was published in Cancer Epidemiology, Biomarkers & Prevention .

What is ductal carcinoma in situ (DCIS)?

Ductal carcinoma in situ (Ductal Carcinoma In Situ, DCIS) is the start of cancerous changes in cells lining the breast’s milk ducts and is a very early stage of breast cancer. If your breast biopsy is reported as “ductal carcinoma in situ,” this means that some cells in your breast ducts have begun turning into cancer cells, but they have not yet acquired an invasive (spreading) character and extend only along the milk ducts, not into the breast tissue. The main treatment for DCIS is surgery, in which the tumor is removed together with some normal surrounding tissue. This breast cancer surgery is called “wide local excision” or “lumpectomy.”

Although only some DCIS cases progress to invasive breast cancer, most would not become life-threatening if untreated and left alone. However, current guidelines recommend surgical removal of DCIS, generally followed by radiotherapy and sometimes maintenance endocrine therapy, so most women are overtreated. This makes distinguishing harmless DCIS from DCIS that will progress to invasive breast cancer a major unmet need.

Study details

• The researchers systematically reviewed studies in the PubMed database from 1970 to 2018, totaling 1.781 studies.
• The studies primarily assessed women diagnosed and treated for DCIS for the risk of invasive recurrence Over 1 year of follow-up, at least 10 ipsilateral invasive breast cancer events were identified while assessing this risk.
• Of the 1.781 articles reviewed, 40 met the criteria for inclusion in the meta-analysis. Patient numbers in the included studies ranged from 52 to 37.692, and average follow-up ranged from 3.2 to 15.8 years.

Study results

• Among 26 prognostic factors (predicting the course of disease), researchers found a relative increase of % 36 to % 84 in invasive breast cancer recurrence after DCIS diagnosis associated with 6 factors.
• Among these factors, breast cancer development risk increased;
  • with race (African ancestry), by 1.43 times,
  • with premenopausal status (not yet having reached menopause), by 1.59 times,
  • with a palpable lump, by 1.84 times,
  • with positive surgical margins, by 1.63 times,
  • with high histological grade, by 1.36 times, and
  • with high p16 protein expression, by 1.51 times. 
• The highest risk of bias arose from inadequate handling of confounders and poorly defined study groups.