What Is Stage 0 Breast Cancer, and What Are the Signs Women Should Know?

When you or someone you know is diagnosed with breast cancer, it can be daunting and overwhelming. One term you may have heard is “stage 0 breast cancer.” But what does it really mean? And how is it different from other stages of breast cancer?

Before anything else, it's important to remember that you have many options. To learn more, we spoke with healthcare professionals specializing in cancer treatment. They provide more insight into stage 0 breast cancer, including what the diagnosis really means, treatment options and the long-term prognosis. 

What is stage 0 breast cancer?

Stage 0 breast cancer, also known as ductal carcinoma in situ (DCIS), is essentially a precancerous condition. This means that “the cancer is contained within the milk ducts and doesn’t have the ability to spread outside the breasts,” explains Anne Peled, MD, Breast Cancer and Plastic Surgeon at Sutter Health Breast Cancer Center of Excellence. It accounts for 20 percent of all newly diagnosed breast cancers. 

“Stage 0 cancer is technically classified as breast cancer, which understandably carries a lot of fear with it,” she says. “But many breast cancer specialists and researchers have been working to better understand which of these are likely never going to be anything concerning and could potentially be reclassified as pre-cancer, to try to better help patients get appropriate treatment and not get over treated.” 

While the exact cause of stage 0 breast cancer remains unclear, factors like increasing age, history of benign breast breast disease and inherited gene mutations may play a role.

What are the symptoms of stage 0 breast cancer?

In many cases, Dr. Peled says “there are not any signs or symptoms of stage 0 cancer.” That said, Lisa Redden. MD, Medical Oncologist with the University of Maryland St. Joseph Medical Center, notes that some women may have “a breast lump, skin changes or itching on the breast or new nipple discharge that prompts them to get checked.” 

How stage 0 breast cancer is diagnosed

“[Stage 0 breast cancer] is almost always diagnosed from a routine mammogram or breast MRI,” says Dr. Peled. Sometimes, it may be detected through a clinical breast exam or because of symptoms like a lump or nipple discharge. If your doctor suspects you might have it, they will likely perform a biopsy to confirm the diagnosis.

“When cancer is caught at this earliest stage, before it becomes [an] invasive disease, the prognosis is excellent,” adds Dr. Redden. 

Stage 0 breast cancer treatment

“Stage 0 breast cancer is highly treatable,” says Dr. Redden. “Patients who receive treatment have very good outcomes, but it should not be ignored. If left untreated, stage 0 breast cancer is likely to turn into more advanced, higher-stage cancer.”

“Often stage 0 cancer can be treated with a small surgery called a lumpectomy,” Dr. Peled explains. “Though sometimes a mastectomy is recommended if the cancer is more extensive within the breast or for other factors such as family history or genetic testing.”

Dr. Redden adds that “depending on the amount of disease and type of surgery, [surgery] is often followed by radiation and a hormone pill to prevent recurrence.” Importantly, “this early-stage disease does not require treatment with chemotherapy. Patients who receive these treatments have excellent survival rates and low risk of recurrence of their cancer.” The five-year survival rate is 99 percent. 

The importance of routine mammograms

Getting your routine screening mammograms is the best way to detect early-stage breast cancer before it becomes a more invasive breast cancer. Dr. Redden advises her patients to start before the age of 40.

“The sooner breast cancer is detected, the easier it is to treat,” she says. “Also, for patients that have other family members with breast cancer, especially if those family members were diagnosed at a young age, it is a good idea to ask your doctor if you need to start screening before age 40.”

More on cancer self-care and prevention:

These Tips From Experts and Real Women Can Help You Manage Your Cancer Treatment

These Breast Cancer-Fighting Foods May Prevent Up To 50% of Cases

What Is Preventative Chemotherapy? A Look Into the Treatment Plan Used by Kate Middleton and Ann Wilson

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.