Following a breast cancer diagnosis, it’s natural to wonder about your prognosis. “Prognosis” refers to the overall outlook of a disease — how well it generally responds to treatment and how it may affect your life expectancy. A prognosis can’t predict the future for any one individual. It’s important to discuss your cancer prognosis with your doctor to better understand the road ahead.

Factors That Influence Breast Cancer Prognosis

The stage of a person’s breast cancer is an important predictor of their prognosis. The stages of the disease range from 0 to 4 (sometimes written in Roman numerals, such as stage II instead of stage 2 or stage 4 instead of stage IV). Stages can also have substages, denoted by a letter (e.g., stage 2A). These are based on factors such as tumor size and types of cancer cells. A doctor will determine a person’s stage at diagnosis, based on how far the cancer has spread throughout the body.

For early-stage and locally advanced breast cancer (stages 0 through 3), a doctor will consider the following variables when estimating a person’s prognosis:

• Tumor size
• Tumor grade, which pertains to how abnormal the cancer cells look under a microscope compared to normal cells
• How many lymph nodes contain cancer cells

Additionally, there are important genetic features present in some breast cancers that also factor into treatment options and prognosis:

• HER2 status — Whether or not the cancer cells contain high levels of a protein called human epidermal growth factor receptor 2
• Hormone receptor status — Whether the cancer cells contain the estrogen receptor (ER) or progesterone receptor (PR)
• The genetic profile of the tumor, as determined by a diagnostic test such as Oncotype Dx

Early detection of breast cancer leads to a better prognosis. If the breast cancer has spread to other parts of the body, then it is known as metastatic breast cancer or stage 4 breast cancer. The presence of metastases has a negative impact on breast cancer survival.

How Are Survival Rates Determined?

Survival rate is the standard measure of prognosis in cancer research. Researchers determine survival rates by tracking the outcome of large groups of people following a breast cancer diagnosis. One of the most common measurements is the five-year relative survival rate. This is the relative likelihood that someone with breast cancer will still be alive after five years compared to someone without the disease.

The U.S. National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program tracks outcomes of people living with breast cancer to determine survival rates. Survival rates are measured separately for different kinds of breast cancer.

However, instead of using the clinical stage (0 through 4), SEER classifies breast cancer into one of the following groups:

• Local, for cancers that have not spread beyond the breast
• Regional, for cancers that have begun to infiltrate nearby lymph nodes
• Distant, for cancers that have metastasized to other parts of the body

In contrast, doctors typically classify breast cancer by the clinical stage (0 through 4) as defined by the American Joint Committee on Cancer. When discussing survival, a doctor will assess the prognosis based on the stage of breast cancer and other defining features.

Prognosis for Stage 0 Breast Cancer

Stage 0 breast cancer is the earliest form of breast cancer and is noninvasive, meaning cancer cells are located only in the milk ducts. It is also usually referred to as ductal carcinoma in situ (DCIS).

Once a person with DCIS undergoes surgery to remove the affected breast tissue, they have a very good prognosis, with a five-year survival rate of 100 percent. Although a person may experience a recurrence, which is when the cancer comes back as an invasive disease, most cases of DCIS are cured after initial treatment.

Prognosis for Stage 1 Breast Cancer

Stage 1 breast cancer is the earliest form of invasive breast cancer. Cancer cells have begun to move from the milk ducts into the surrounding breast tissue. The standard treatment approach is surgery with the possible addition of radiation.

Stage 1 breast cancer has a five-year survival rate of nearly 100 percent and is often curable.

Prognosis for Stage 2 Breast Cancer

In stage 2 breast cancer, cancer cells have continued to multiply in the breast tissue and possibly nearby lymph nodes. The standard treatment is still surgery, although chemotherapy and drug therapy may be used in some cases. The five-year survival rate for stage 2 breast cancer is usually greater than 90 percent.

Prognosis for Stage 3 Breast Cancer

The earliest form of advanced stage breast cancer is stage 3 breast cancer. In stage 3, breast cancer cells have infiltrated more lymph nodes and the muscle surrounding the breast. Because the disease is further along at the time of diagnosis, the prognosis is less favorable than that of early-stage breast cancer.

Survival rates range from 66 percent to as high as 98 percent. This wider range of outcomes is due to additional substages included in stage 3 cancer, along with molecular features that can affect treatment options.

Prognosis for Stage 4 Breast Cancer

Stage 4 breast cancer is the most advanced-stage breast cancer. It’s distinguished by the presence of metastases, or new tumors on other organs after the cancer has spread to different parts of the body. It is treatable with chemotherapy and drug therapy, but it is not curable.

Due to the advanced nature of the disease, stage 4 breast cancer has a poorer prognosis. The five-year survival rate is around 29 percent for women and 22 percent for men, according to Cancer.Net.

Prognosis for Triple-Negative Breast Cancer

Some breast cancers contain high levels of the HER2 protein or hormone receptors — namely, estrogen receptor or progesterone receptor. These cancers can be successfully treated with drugs that target those specific proteins.

However, some cases are negative for ER, PR, and HER2. This is known as triple-negative breast cancer (TNBC), which is notoriously difficult to treat.

Although triple-negative breast cancer can be at any stage of invasive breast cancer, it is a more aggressive disease with fewer treatment options, and therefore has a worse prognosis relative to other invasive breast cancers.

According to the American Cancer Society, the five-year survival rates for women with TNBC, based on different SEER stages, are as follows:

• Local — 91 percent
• Regional — 65 percent
• Distant — 12 percent

Prognosis for Inflammatory Breast Cancer

Inflammatory breast cancer is a rare form of invasive breast cancer that is characterized by distinct changes to the breast, including inflamed skin. It is associated with a worse prognosis relative to other forms of advanced breast cancer.

According to the American Cancer Society, the five-year survival rates for women with inflammatory breast cancer, by SEER stage, are:

• Regional — 54 percent
• Distant — 19 percent

Improving Survival Rates for Breast Cancer

While early detection of breast cancer results in better treatment outcomes, research is ongoing to improve survival for those with metastatic disease or more aggressive forms of breast cancer. There have been significant advances in recent years: The U.S. Food and Drug Administration (FDA) has approved newer breast cancer treatment approaches, such as immunotherapy drugs, that are more effective against TNBC than standard treatments.

Although progress is being made, there is still much work to be done. Continued participation in oncology clinical trials — research studies on the effects of new treatments — can advance the discovery of more effective therapies and lead to improved outcomes for advanced breast cancer.

Beyond medical interventions, some lifestyle changes may help people living with breast cancer live longer, including maintaining a healthy weight, eating a healthy diet, and getting sufficient exercise.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, over 57,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you or a loved one been diagnosed with breast cancer? Did your doctor give you a detailed prognosis? Share your experiences in the comments below, or start a conversation by posting on MyBCTeam.