DCIS (Stage 0 Breast Cancer)

What You Should Know

What is DCIS?

Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside a milk duct in one of both breasts. DCIS is considered noninvasive and is the earliest form of breast cancer and is sometimes referred to as Stage 0 (zero).

No, DCIS and invasive breast cancer are not the same. DCIS is considered noninvasive, meaning it has not spread from the milk ducts, which are the passages that drain milk from the lobules to the nipple. Invasive breast cancer begins either in the cells of the lobules, which are milk-producing glands, or the milk ducts. Invasive breast cancers grow or invade into normal, healthy tissues.

Earty Stage Breast Cancer diagram

DCIS Treatment Options

You may be recommended one or a combination of treatments depending on your personal risk of recurrence. Important in your decision is your personal situation and perception of risk and the potential benefit and associated side effects of each treatment.

Surgery icon


Minor surgery removing diseased tissue. Also known as Breast Conserving Surgery (BCS)

Mastectomy (with or without reconstruction):

Surgery removing entire breast

Radiation RT diagram

Whole Breast Radiation:

External radiation of the entire breast

Partial Breast Radiation:

Focused radiation on the area of tissue removal

Anti-estrogen Medication diagram

Anti-estrogen (or endocrine) medication for 5 years:

May benefit some women with hormone receptor (ER/PR) positive disease. Also called hormonal therapy.


Short Term:

  • Pain or tenderness
  • Swelling
  • Hematoma

Long Term:

  • Lymphedema
  • Limited arm or shoulder movement
  • Numbness in chest or upper arm
  • Nerve pain in the chest wall, armpit, and/or arm

Radiation Therapy4

Short Term:

  • Pain and skin changes
  • Fatigue
  • Insomnia

Long Term:

  • Breast and skin changes
  • Lymphedema
  • Rib Fracture
  • Pain
  • Rare Secondary Cancer

Anti-estrogen Medication5


  • Hot flashes and night sweats
  • Irregular periods
  • Loss of sex drive
  • Vaginal discharge, dryness, or itching


  • Blood clots in the large veins (deep venous thrombosis)
  • Blood clots in the lungs (pulmonary emboli)
  • Bone loss (premenopausal women only)
  • Uterine or endometrial cancer
  • Cataracts
  • Stroke

A diagnosis of DCIS increases the risk of return of DCIS or an invasive breast cancer diagnosis in the future. While risk cannot be completely eliminated, it may be decreased through one or a combination of treatments. The impact of treatments reported below are averages, so it is important to understand your individual risk or recurrence and your personal benefit.

  • The lifetime average risk of a female developing breast cancer is 12% (or 1 in 8).1
  • DCIS has a lower risk profile than invasive breast cancer. Survival after a diagnosis of DCIS is very high (~96%) regardless of the type of surgery (BCS or mastectomy) or addition of radiation therapy.2

Factors that may increase your risk of DCIS include:12

  • Increasing age
  • Personal history of benign breast disease, such as atypical hyperplasia
  • Family history of breast cancer
  • Never having been pregnant
  • Having your first baby after age 30
  • Having your first period before age 12
  • Beginning menopause after age 55
  • Genetic mutations that increase the risk of breast cancer, such as those in the breast cancer genes BRCA1 and BRCA2
Studies have found that the majority of invasive breast cancer genetic predisposition loci also predispose to DCIS. With confirmed inherited genetic links, family history of invasive breast cancer and DCIS could be important in assessing a woman’s risk.11
About 60,000 cases of DCIS are diagnosed in the United States each year, accounting for about 1 out of every 5 new breast cancer cases.10

See how DCISionRT can provide you and your doctor helpful information to guide your radiation treatment decisions.

More Info

1 U.S. Department of Health and Human Services, National Institutes of Health, National Cancer Institute. (2015). Cancer Stat Facts: Female Breast Cancer. Retrieved from https://seer.cancer.gov/statfacts/html/breast.html
2Hwang S. Estimating the magnitude of clinical benefit of local therapy in patients with DCIS. The Breast. 2019;44. doi:10.1016/s0960-9776(19)30073-6.
3American Cancer Society. (2019). Mastectomy. Retrieved from https://www.cancer.org/cancer/breast-cancer/treatment/surgery-for-breast-cancer/mastectomy.html
4Susan G. Komen. (2020). Side Effects of Radiation Therapy. Retrieved from https://ww5.komen.org/BreastCancer/SideEffectsofRadiationTherapy.html
5Susan G. Komen. (2020). Side Effects of Tamoxifen. Retrieved from https://ww5.komen.org/BreastCancer/SideEffectsofTamoxifen.html
6Miller M, et al. Contralateral Breast Cancer Risk in Women with Ductal Carcinoma In Situ: Is it High Enough to Justify Bilateral Mastectomy? Annals of Surgical Oncology. 2017;24(10):2889-2897. doi:10.1245/s10434-017-5931-2.
7Overview of the Randomized Trials of Radiotherapy in Ductal Carcinoma In Situ of the Breast. by EBCTCG JNCI Monographs. 2010;2010(41):162-177. doi:10.1093/jncimonographs/lgq039.
8Cuzick J, et al. Eect of tamoxifen and radiotherapy in women with locally excised ductal carcinoma in situ: long-term results from the UK/ANZ DCIS trial. The Lancet Oncology. 2011;12(1):21-29. doi:10.1016/s1470-2045(10)70266-7.
9Timbrell S, et al. Comparison of Local Recurrence After Simple and Skin-Sparing Mastectomy Performed in Patients with Ductal Carcinoma In Situ. Annals of Surgical Oncology. 2016;24(4):1071-1076. doi:10.1245/s10434-016-5673-6.
10Breastcancer.org. (2019). Ductal Carcinoma In Situ: Symptoms, Diagnosis, and Treatment. Retrieved from https://www.breastcancer.org/symptoms/types/dcis#:~:text=According%20to%20the%20American%20Cancer,are%20living%20much%20longer%20lives
11Petridis, C., Brook, M.N., Shah, V. et al. Genetic predisposition to ductal carcinoma in situ of the breast. Breast Cancer Res 18, 22 (2016). https://doi.org/10.1186/s13058-016-0675-7.
12Mayo Clinic. (2020). Ductal Carcinoma in Situ (DCIS). Retrieved from https://www.mayoclinic.org/diseases-conditions/dcis/symptoms-causes/syc-20371889.

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