An Overview of Stage 0 Breast Cancer

Understanding DCIS

Stage 0 breast cancer, which includes ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS), is an early form of breast cancer that originates in the milk ducts or lobules of the breast. Carcinoma in situ means that the cancer is contained within the duct or lobule where it started and has not spread to other areas of the breast or lymph nodes.

About 20% of all newly diagnosed breast cancers are DCIS. When caught and treated at stage 0, DCIS has an excellent prognosis.

This article will outline the symptoms, treatments, and advice for coping with early-stage breast cancer.

stage 0 breast cancer
Verywell / Gary Ferster

Overview

Stage 0 breast cancer 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.

Precancer or Noninvasive Cancer?

There is some debate over whether to consider DCIS precancer or noninvasive cancer. Generally, DCIS is considered non-invasive cancer, and LCIS is considered a precancerous condition, also called lobular neoplasia.

The milk ducts are tubes through which mild flows during breastfeeding, while the breast lobules are clusters of cells where the milk is produced.

A diagnosis of DCIS or LCIS may make you worry that your condition will inevitably progress to cancer. This is not always the case. However, these conditions should be monitored closely.

Diagnosis

A mammogram can often detect the abnormal cells of stage 0 breast cancer. If an area of your breast appears concerning, the next step is to have a needle biopsy, which is a procedure that removes cells in the area of concern. The cells are analyzed under a microscope by a pathologist.

Staging

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 details about these classifications.

Using this classification system, stage 0 can be grouped as follows:

  • Tis: This indicates 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, 1, 2, 3, or 4 is assigned. 

Treatment

Not all stage 0 breast cancers require treatment. Sometimes active monitoring or a watch-and-wait approach is recommended to see if the carcinoma will remain stable or if it will progress. And sometimes cancer treatments such as surgery, radiation, or hormone therapy are recommended.

Numerous factors will affect your treatment plan.

Some of these include:

  • Age: Younger women are more likely to be at risk for local cancer recurrence and may opt for treatment sooner.
  • Fertility: Many women can get pregnant after receiving hormone therapy, but sometimes this type of therapy can affect fertility. Some people preserve their eggs before starting treatment.
  • Hormone status: Breast cancer cells that have estrogen and progesterone receptors may respond to hormone therapy.
  • Genetic risk: Having a mother, aunt, or sister with breast or ovarian cancer increases your risk of recurrence.
  • Menopausal status: Response to different treatments varies based on menopausal status.

Personal preferences play a role in the treatment plan as well. Some people would prefer having any abnormal cells surgically removed, whereas others are more comfortable with a conservative approach of waiting, along with careful follow-up.

Treatment options may include:

  • Lumpectomy (surgery to remove the cancerous tissue and a rim of normal tissue around it), followed by radiation (using high doses of radiation to kill cancer cells)
  • Mastectomy (surgery to remove the breast) if there's a concern that there may be other regions of cancer 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 they block estrogen in hormone-receptor positive breast cancers.

Breast Cancer Healthcare Provider 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 localized stage 0 breast cancer is detected early and treated, the five-year relative survival rate is 90%, according to the American Cancer Society.

Follow-Up Care

After treatment for stage 0 breast cancer, there's a small risk of recurrence or future development of invasive breast cancer. After complete surgical removal of stage 0 cancer, there is a risk of new breast cancer that's not related to first breast cancer—this risk is similar to the risk for women who have never had breast cancer.

Your healthcare provider may recommend more frequent exams and/or tests so any future cancers can be caught and treated early.

Coping

Understanding of what stage 0 breast cancer is (and isn't) is one of the best steps you can take to cope with your diagnosis. It puts your condition in perspective and can help temper worries.

Although 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.

An organization called CancerCare.org has individual counselors and support groups to help connect you with others in the same situation. They also offer education and financial assistance.

Summary

Stage 0 breast cancer, DCIS and LCIS, is the earliest stage of localized breast cancer, affecting approximately 51,400 women this year. Being diagnosed at this early stage sets you up for an excellent outcome. After getting a diagnosis, considering a few different factors will help you and your medical team make the best decisions for your treatment and follow-up care.

A Word From Verywell

A cancer diagnosis can be overwhelming. But with a stage 0 diagnosis, you're facing the best-case scenario by catching it early. Work closely with your healthcare provider to create a treatment plan that's best for you, and move forward with the knowledge that what you have is treatable and highly curable.

Frequently Asked Questions

  • Can stage 0 breast cancer come back?

    Yes, there is a low risk, and recurrence may be related to age. Younger women are more likely to be at risk for local recurrence and may opt for treatment sooner.

  • Is surgery necessary for stage 0 breast cancer?

    Not always. Some physicians recommend a wait-and-see approach. Sometimes, surgery—whether it is a lumpectomy or mastectomy—may be recommended.

  • Who is at risk for stage 0 breast cancer?

    Anyone can be at risk for stage 0 breast cancer. Risk increases if you have a direct relative with breast cancer or if you carry genetic mutations for breast cancer, like BRCA1/BRCA2.

  • Should I have a mastectomy for DCIS?

    Having a mastectomy is a very personal decision. You should talk about your options with your physician and an oncology surgeon who specializes in breast cancer. If you have a family history of breast cancer, you may have a higher sense of urgency to have this procedure rather than waiting it out.

Originally written by
Pam Stephan
Pam Stephan is a breast cancer survivor.
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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading