Nina Zeldes, National Center for Health Research
Thanks to widespread use of screening mammography, there has been a dramatic increase in women diagnosed with ductal carcinoma in situ (DCIS), the most frequently diagnosed type of Stage Zero breast cancer. It accounts for 20-25% of new breast cancer cases diagnosed each year. DCIS is referred to as “stage zero breast cancer” or a “pre-cancer” because it is not invasive. It is almost always diagnosed on a mammogram, where it looks like white specks. DCIS rarely forms a lump, which is why it isn’t diagnosed by a breast exam. In DCIS, some of the cells lining the ducts (the parts of the breast that secrete milk) have developed abnormally, but since it is not invasive, it does not spread unless the DCIS changes into stage 1 breast cancer.
DCIS is not painful or dangerous and most women with DCIS will never develop invasive cancer whether they are treated or not. But DCIS can change into stage 1 breast cancer, and it is impossible to predict which women with DCIS will develop cancer and which ones won’t. That’s why treatment is recommended. Fortunately, only 3% of women treated for DCIS die of breast cancer within 20 years.
What are Your DCIS Treatment Options?
DCIS usually grows slowly. A patient can spend a few weeks after her diagnosis to talk with her doctors, learn the facts about her treatment choices, and think about what is important to her before she chooses which kind of treatment to have.
Treatment choices for DCIS are similar to those for invasive breast cancer. Most patients can choose fewer treatments with fewer side effects, but surgery to remove the DCIS is almost always recommended.
Most DCIS patients can choose a lumpectomy (which removes the DCIS but does not remove the entire breast). Radiation therapy and/or hormonal therapy are often recommended to reduce the chances of recurrence, although neither increases the already very good chances of survival.
Sentinel Lymph Node Biopsies for DCIS – Beneficial or Overtreatment?
Some DCIS patients that choose lumpectomy are encouraged to undergo a sentinel lymph node biopsy, which removes a few lymph nodes from under the arm to check if cancer has spread there. However, since DCIS does not spread, experts generally do not recommend this procedure for patients diagnosed with DCIS.
Despite this, approximately one in four women diagnosed with DCIS currently undergo sentinel lymph node biopsies. Is this a good way to “be cautious” to prevent breast cancer in the future, or is it overtreatment?
To find out if there are any long-term benefits for women, Dr. Shiyi Wang and his colleagues at Yale University published a study in 2019 that looked at 5,957 women who were diagnosed with DCIS and had undergone a lumpectomy, and compared the women who had also undergone sentinel lymph node biopsies with those who had not.
They found that over the next 5.75 years, the biopsy did not:
- decrease DCIS patients’ chances of undergoing mastectomy (removal of the breast)
- decrease DCIS patients’ chances of developing invasive breast cancer
- reduce the likelihood of a DCIS patient dying from breast cancer
At the same time, the study found that having the biopsy increased the risk for several serious side effects, such as pain, wound infection, and lymphedema. Lymphedema is a painful, chronic condition that can restrict a woman’s arm movements.
The researchers therefore concluded that there are no long-term benefits for undergoing sentinel lymph node biopsies for DCIS patients, and that the risks of complications should convince most DCIS patients and their physicians not to undergo the procedure.
The study was limited to older women (67-94) and did not control for risk factors such as obesity or using hormonal therapy such as Tamoxifen or aromatase inhibitors. For that reason, the results might not be relevant to younger women or women with a high-risk type of DCIS, which can be diagnosed prior to surgery. The possible impact of hormonal therapy or weight is unknown. However, the study has important implications for tens of thousands of women with the most common type of stage zero breast cancer (DCIS).
Bottom Line: Most women who receive a lumpectomy for DCIS (stage zero breast cancer) are being overtreated if they undergo a sentinel lymph node biopsy. The most recent research shows that this procedure has no long-term benefits for most DCIS patients and can cause long-lasting pain and other problems.
Read more information about this study here. You can access the study by clicking on the following link: Long-Term Outcomes of Sentinel Lymph Node Biopsy for Ductal Carcinoma in Situ.
For more information about surgery options for DCIS, see our free DCIS patient booklet. Find out if women with pre-cancers are getting mastectomies they don’t need here. You can also find some more general information about DCIS here. If you want to find out more about radiation therapy for DCIS click here. For more information about hormone therapy, such as Tamoxifen, for DCIS, click here.
All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.
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- Hung, Peiyin, et al. “Long-Term Outcomes of Sentinel Lymph Node Biopsy for Ductal Carcinoma in Situ.” JNCI Cancer Spectrum 3.4 (2019): pkz052.