Breast Cancer Stage Zero

DCIS and LCIS: Cancer or Not?

female radiologist looking at breast
What exactly is stage zero breast cancer?. Javier Larrea / Getty Images

What does it mean to be told you have breast cancer stage zero? The confusion over what the staging means can lead to misunderstanding of the condition, treatment course, and outcomes.

DCIS or Stage 0 Breast Cancer is Often Misunderstood

Many people who have been diagnosed with ductal carcinoma in situ (DCIS) or stage 0 breast cancer find it frustrating when they talk to others. Some people make comments that "it's not really cancer" or "you aren't in danger at all" and these messages can be very painful.

After, many of these people have been treated with surgery and radiation and are looking at five years or more of using hormone therapy. Such comments then are invalidating, and leave women feeling that their diagnosis has been belittled and their emotions dismissed.

Any diagnosis of cancer or precancer (whichever it is) is terrifying. Studies have found that the emotions people experience at the time of diagnosis are similar whether a person is diagnosed with an early highly-curable tumor or an advanced stage tumor with no chance of a cure.

This confusion over a diagnosis of in-situ breast cancer is common. Let's take a look at the reasons for the confusion and find out what the facts are about the stage 0 breast cancers DCIS and its cousin LCIS (lobular carcinoma in situ).

Cancer In Situ

A diagnosis of carcinoma in situ has a specific meaning. In situ means that the cancer cells are all "in place" and not invasive.

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 cells. Oncologists call this type of diagnosis stage zero because it has not broken out of place (has not spread beyond something called the basement membrane), nor has it invaded other tissues.

The cells in carcinoma in situ look identical to the cancer cells in invasive cancer, the only difference is how far the cells have spread.

Invasive breast cancers are assigned a stage number from one to four and it is important to remember that the lower stages are easier to treat, resulting in higher survival rates.

Stage Zero Breast Cancer

The American Joint Committee on Cancer (AJCC) publishes the standards by which cancers are staged. Breast cancer is staged by the TNM system, with numbers assigned to a score for the Tumor, Nodes, and Metastasis. Tis N0 M0 describes DCIS and LCIS as well as Paget's disease of the nipple, if no tumor is detected.

  • Tis means that no tumor was found, but abnormal cells are present.
  • N0 means no lymph nodes are involved.
  • M0 confirms that no metastasis has occurred.

That is what an oncologist is saying when they tell you that you have stage zero breast cancer.

Precancer or Noninvasive Cancer?

Some physicians use the terms  precancerous and noninvasive cancer interchangeably whereas others simply refer to stage 0 breast cancer as "cancer." Either way, they are talking about the same process only with different terms.

But when you hear the term "precancerous," you may worry that you've got a condition that will inevitably progress to cancer, and must be treated as such.

Then again, if you're told that your diagnosis is "noninvasive cancer," you may freeze with fear upon hearing the "C" word! Let's face it: We don't like either term, especially when it is referring to our breasts.

Is Stage Zero Cancer or Not?

Both ductal and lobular carcinoma in situ are worrisome because they have the potential to invade beyond their well-contained sites. Scientists can't tell exactly which people will be more at risk of developing invasive breast cancer if their DCIS or LCIS is left untreated. Both carcinomas have the cellular appearance of cancer and both might eventually grow and spread beyond their original clumps, or they might not.

Since there is a potential of developing invasive cancer, most people and their physicians opt to treat stage 0 breast cancer as they would an invasive cancer (stage I to stage IV).

Many other factors affect your treatment plan. Some of these include:

  • Hormone status
  • Genetic risk
  • Menopausal status
  • Personal preferences

Treatment Options

Treatment options vary depending on the above factors and more.

Some oncologists may tell you to "watch and wait" to see if the carcinoma will resolve on its own or if it will progress. Other doctors will proceed to recommend standard cancer treatments. Some people "just want it out" if there is a chance that stage 0 could become invasive cancer, whereas other people are more comfortable with a conservative approach of waiting along with careful follow-up.

Treatments options may include a lumpectomy followed by radiation, or mastectomy if there is concern that there may be other regions of DCIS or LCIS in the breast or if a woman has a strong family history of breast cancer. Hormone therapy may follow for at least 5 years, with tamoxifen often used for premenopausal women and aromatase inhibitors for those who are postmenopausal.

Either way, you will face uncomfortable decisions and a range of emotions. People who will be supportive of you must respect that regardless of your specific diagnosis.

So, is stage zero really breast cancer, or not? Doctors still don't agree on this, but that is a matter of terminology. Don't get hung up on the words, but do consider getting a second opinion, to make sure that you get the best and most effective treatment for your health.

Sources:

Rosso, K., Weiss, A., and A. Thompson. Are There Alternative Strategies for the Local Management of Ductal Carcinoma in Situ. Surgical Oncology Clinics of North America. 2018. 27(1):9-80.

Toss, M., Miligy, I., Thompson, A. et al. Current Trials to Reduce Surgical Intervention in Ductal Carcinoma In Situ of the Breast: Critical Review. Breast. 2017. 35:151-156.