A new study has been released suggesting that patients who receive a diagnosis of DCIS (ductal carcinoma in situ) may be receiving over-treatment. The observational study followed a group of over 100,000 women over 20 years and showed that regardless of treatment type (lumpectomy or mastectomy), those treated for DCIS had approximately the same chance of dying from breast cancer as the average woman does. The data did, however, show that younger women under the age of 40 with DCIS are at a higher risk.

The main points from the research, as summarized in the paper in JAMA Oncology:

  • The purpose of this study was to estimate the mortality from breast cancer following a diagnosis of ductal carcinoma in situ (DCIS) and to identify risk factors for death from breast cancer.

  • The 20-year breast cancer–specific mortality rate following a diagnosis of DCIS was 3.3%.

  • Young age at diagnosis and black ethnicity were significant predictors of breast cancer mortality.

  • Prevention of invasive in-breast recurrence with either radiotherapy or mastectomy did not prevent death from breast cancer.

  • The clinical course of women with DCIS is similar to that of women with small invasive breast cancers.

If you are a young woman who has been diagnosed with DCIS (“stage 0″) breast cancer, discuss these findings with your medical team and make sure you understand what the research means for you.