An Overview of Stage 0 Breast Cancer

Understanding DCIS and LCIS

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Stage 0 breast cancer means you have abnormal cells in the lining of the milk ducts of your breast, but they are contained to the ducts or lobules and haven't invaded the surrounding breast tissues. There are two types of stage 0 breast cancer (DCIS and LCIS), both of which are "in situ" cancers. The cells in carcinoma in situ look identical to the cancer cells of invasive cancer. The only difference is the fact that they are "in place" and have not spread.

When caught and treated at stage 0, these cases have an excellent prognosis.

stage 0 breast cancer
Verywell / Gary Ferster


Carcinoma in situ, whether it is found in the lining of your milk ducts or inside the lobes where breast milk is produced, is a contained clump of abnormal cells. Oncologists call it stage 0 because it hasn't broken out of place (has not spread beyond what's called the basement membrane) or invaded other tissues.

The two types of stage 0 breast cancer are:

Precancer or Noninvasive Cancer?

Some physicians use the terms precancer and noninvasive cancer interchangeably when referring to stage 0 breast cancer, whereas others simply call it cancer. There is great debate over this, but generally, DCIS is considered cancer, while LCIS isn't (despite it being given a stage 0 designation).

Aside from clinical perspectives that shape their opinion on the proper terminology to use, some physicians consider how hearing "cancer" will affect a patient.

Learning that your condition is "precancerous" may make you worry that it will inevitably progress to cancer and that it must be treated as such (it might, but that is not inevitable). On the other hand, people told that they have a "noninvasive cancer" often lump their condition in with more advanced (and serious) cases of the disease. In fact, some doctors refer to LCIS as lobular neoplasia simply because it sounds less frightening.

Don't be mistaken: Both DCIS and LCIS are concerning because they have the potential to invade beyond their well-contained sites. Both carcinomas have the cellular appearance of cancer and both might eventually grow and spread beyond their original clumps. But, they also might not. So far, doctors can't say which direction any particular case will go.

While stage 0 breast cancer should be taken seriously, the lower the stage number, the easier the disease is to treat. (Invasive breast cancers are assigned a stage number from 1 to 4.)

Remember that all of these names for stage 0 breast cancer are just different ways to refer to the same thing. Don't get hung up on terms when deciding on treatment.


The staging system most often used for breast cancer is the American Joint Committee on Cancer (AJCC) TNM system. The TNM Staging System is based on the extent of the tumor (T), the extent of spread to the lymph nodes (N), and the presence of metastasis (M). Numbers or letters after T, N, and M provide more details about these classifications. Using this classification system, stage 0 can be grouped as follows:

  • Tis: Carcinoma in situ (DCIS, or Paget's disease of the breast)
  • N0: Cancer has not spread to the nearby lymph nodes.
  • M0: X-rays (or other imaging tests) have concluded that cancer has not spread to other parts of the body (metastasized)

Once the T, N, and M are determined, they are combined, and an overall stage of 0, I, II, III, IV is assigned. 


Not all stage 0 breast cancers require treatment. Some oncologists may tell you to "watch and wait" to see if the carcinoma will resolve on its own or if it will progress. Others recommend standard cancer treatments.

In terms of patient perspectives, some people "just want it out" if there is a chance that stage 0 could become invasive cancer, whereas others are more comfortable with a conservative approach of waiting along with careful follow-up.

Numerous factors will affect your treatment plan. Some of these include:

Treatments options may include a lumpectomy followed by radiation, or mastectomy if there's a concern that there may be other regions of DCIS or LCIS in the breast or if there's a strong family history of breast cancer.

Hormone therapy may follow for at least five years, with tamoxifen often used for premenopausal women and aromatase inhibitors for those who are postmenopausal.

As with any cancer diagnosis, you should consider getting a second opinion to make sure you get the best and most effective treatment for you.

Breast Cancer Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Old Woman

Survival Rates

The outlook is good for people diagnosed with stage 0 breast cancers. When detected early and treated, the five-year relative survival rate is 99%.

The five-year survival rate drops to 93% for stage 2 cancer and 73% for stage 3 diagnoses. That shows you how important it is to catch breast cancer early.

Follow-Up Care

After treatment for stage 0 breast cancer, you face a small risk of recurrence or the future development of invasive breast cancer. Your doctor may recommend more frequent exams and/or tests so any future cancers can be caught and treated early.


Better understanding of what stage 0 breast cancer is (and isn't) is one of the best things you can do to cope with your diagnosis. It puts your condition in perspective and can help temper worries that may be unsubstantiated.

Beyond that, you may become frustrated when talking about your diagnosis with others who are, perhaps, less educated on the topic. Some people may say "it's not really cancer" or "you aren't in danger at all." Stage 0 breast cancer may mean surgery and radiation, plus five or more years of hormone therapy. These treatments are significant and comments that invalidate your experience can leave you feeling that your diagnosis has been belittled and your emotions dismissed.

Any diagnosis involving the word "cancer," including precancer, is undoubtedly worrisome and it should be taken seriously, regardless of the outlook. Studies have found that the emotions people experience when diagnosed are similar whether it's an early, highly curable tumor or advanced cancer with no chance of a cure.

Do your best to explain this to others, if you wish, but work to surround yourself with people who support you and your experience.

While it's common to feel helpless at first, know that the more you educate yourself about treatment options and the emotional aspect of the diagnosis, the better prepared you'll be to deal with the road ahead.

A Word From Verywell

No one wants their doctor to say "cancer" or anything akin to it. But with a stage 0 diagnosis, you're facing the best-case scenario by catching it early. Work closely with your doctor to formulate the treatment plan that's best for you and move forward with the knowledge that what you have is not only treatable but highly curable.

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  1. American Cancer Society. Lobular Carcinoma in Situ (LCIS). Updated September 2019.

  2. Gradishar WJ, Anderson BO, Balassanian R, et al. Breast Cancer, Version 4.2017, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2018;16(3):310-320. doi:10.6004/jnccn.2018.0012

  3. McCormick B, Winter K, Hudis C, et al. RTOG 9804: a prospective randomized trial for good-risk ductal carcinoma in situ comparing radiotherapy with observation. J Clin Oncol. 2015;33(7):709-715. doi:10.1200/JCO.2014.57.9029

  4. Ganz PA. Quality-of-life issues in patients with ductal carcinoma in situ. J Natl Cancer Inst Monogr. 2010;2010(41):218-222. doi:10.1093/jncimonographs/lgq029

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