Understanding Stage 0 Breast Cancer

Medically Reviewed by Melinda Ratini, MS, DO on September 30, 2022
Written by Kristen Fischer
5 min read

So the doctor says you have stage 0 breast cancer, and now you have lots of questions. What does that mean? Is it even really cancer?

Doctors aren’t sure. Some experts consider it the earliest stage of breast cancer. Others think of it as a sort of precancer stage.

Cancer is defined as a group of diseases with abnormal cells that divide without control. Those cells can also invade nearby tissues. Stage 0 breast cancer is not invasive, though it could be later. It’s less advanced than stage I cancer. Basically, it’s still in your milk ducts and hasn’t spread to other nearby tissues.

There are two types of stage 0 breast cancer:

Ductal carcinoma in situ (DCIS). This is what most people mean when they talk about stage 0 breast cancer. The abnormal cells are still in your milk ducts and haven’t affected the fatty tissue that makes up most of your breast. There’s no known cause, and most people don’t have any symptoms, though you may notice a lump or bloody discharge from your nipple. The abnormal cells may or may not become invasive and start to spread. There’s no way to predict if this will happen.

Noninvasive Paget’s disease of the nipple. This is a rare form of breast cancer.

 

Overall, many people don’t have symptoms with stage 0 breast cancer. If you have Paget’s disease of the nipple, you may have these symptoms:

  • Tingling or redness on the nipple or areola
  • Flaking, crusty, or thickened skin on or around the nipple
  • A flattened or inverted nipple
  • Redness
  • Yellowish discharge

If you have DCIS, you may notice:

Because you may not have any symptoms, the only way to find stage 0 breast cancer is by getting screened. Many people discover it during a routine mammogram. In fact, health care professionals find more than 90% of DCIS during imaging scans.

Risk factors for stage 0 breast cancer are similar to general breast cancer risk factors. Some things that may raise your risk for breast cancer include:

  • Age
  • Family history of breast cancer
  • Never having a child
  • Having your first child after the age of 30
  • Having your first period before age 12
  • Personal history of benign breast disease, like atypical hyperplasia
  • Starting menopause after 55
  • Genetic mutations (changes) known to increase breast cancer risk

If you’re diagnosed with DCIS, your pathology report will come with a grade. Nuclear grade 3 is the most likely to spread; nuclear grade 1 is the least likely. You should also have a test to see if your cancer cells have estrogen receptors. (Your doctor might call this ER-positive or ER+.) If they do, it's a sign that your cancer might progress more slowly.

Meanwhile, your doctor may suggest that you get genetic testing. It can find changes in your genes that may boost your breast cancer risk.

What happens next depends on all these things, as well as your personal choices. Most experts agree that you should get some type of treatment. Even though stage 0 cancer is noninvasive, that could change. Most doctors would say it’s better to be safe than sorry.

Typical DCIS treatments are:

Surgery. For smaller DCIS tumors, you might get a lumpectomy, in which the abnormal cells and some breast tissue are removed. Some people decide to have a mastectomy, in which the breast is removed. After a mastectomy, you might choose to have breast reconstruction surgery.

Radiation therapy.This usually follows a lumpectomy. The radiation attacks any abnormal cells that might have been missed and lowers the risk of getting another breast cancer.

Hormone therapy. Doing thisafter surgery may help stop more cancer from developing in either breast.

Chemotherapy isn’t needed to treat DCIS. That’s because the risk of it spreading very far is low.

About one-third of people with DCIS will likely get invasive cancer. Your doctor might suggest that you skip immediate treatment and keep a close eye on your condition instead.

It’s controversial. If you have surgery (and maybe radiation) right away, you might protect yourself from ever getting invasive cancer. On the other hand, you could end up going through treatment that you really didn’t need.

But if you skip surgery and radiation at first and choose to get screening tests more often, there's a chance you'll end up with cancer that's more advanced (and harder to treat) by the time doctors find it. It's a choice only you and your doctor can make.

If you have stage 0 breast cancer, you have a better outlook and higher overall survival rate than those with stage III or IV breast cancer. This is because the disease hasn’t spread.

People who have “local” breast cancer (meaning abnormal cells are still in the breast, as is the case with stage 0 breast cancer) have a 99% 5-year relative survival rate. This means that people with stage 0 breast cancer are about 99% as likely as someone without cancer to live at least 5 years after diagnosis.

About 1 in 5 new breast cancers will be diagnosed as DCIS.But almost all people with it can be cured. It’s rare for DCIS to come back after you treat it.