Your Guide to Navigating Metastatic Breast Cancer Treatments

Metastatic breast cancer can be a daunting diagnosis, but the prognosis has improved somewhat with advances in treatment.

Also known as stage 4 breast cancer, metastatic cancer is defined as the spread of disease beyond the local breast and nearby lymph nodes. More than 150,000 individuals in the United States are living with a diagnosis of metastatic breast cancer, which accounts for the majority of breast cancer deaths. According to the American Cancer Society, more than 43,000 people, mostly women, died from breast cancer in 2022.

This advanced stage of breast cancer can occur years after an original early-stage breast cancer or it may be the first presentation of breast cancer. Black women are more likely to be diagnosed with later stages of breast cancer and at a younger age. However, the majority of patients living with metastatic breast cancer were initially diagnosed with early-stage breast cancer and took all the right steps to reduce their risk of recurrence.

Metastatic breast cancer symptoms

Breast tumor cells originating from primary breast tumor or regional lymph nodes can spread to any other part of the body, including:

Brain
Lungs
Liver
Bones
Ovaries
Skin

Symptoms related to metastatic breast cancer are primarily dependent on the location of the metastasis, and then on the chronic medical conditions and general health status of the patient experiencing the symptoms.

There are a number of symptom management strategies that can be used to mitigate these toxicities. These may include multidisciplinary collaborations with other specialties, including:

Psychosocial oncology
Palliative care
Oncology rehabilitation

Better quality of life is one of the key goals for the management of metastatic breast cancer that is equally shared by patients, caregivers and clinicians.

Metastatic breast cancer treatment

Breast cancer consists of three major tumor subtypes categorized according to estrogen or progesterone receptor expression (hormone receptor-positive) or ERBB2 (HER2) gene amplification. The three subtypes have distinct risk profiles and treatment strategies.

In metastatic hormone receptor-positive breast cancer, early treatment should be endocrine therapy-based, typically with the incorporation of a cyclin-dependent kinase (CDK) 4/6 inhibitor.

After resistance develops to the available hormonal and targeted therapy options, patients transition to treatment with chemotherapy. Studies have demonstrated equivalent overall survival for sequential single-agent versus combination chemotherapy in metastatic breast cancer, with less toxicity and improved patient quality of life on single agents.

HER2-positive breast cancer is often treated with an initial combination of chemotherapy and HER2-targeted therapies.

When hormone receptor expression and HER2 markers are negative, this is known as triple-negative breast cancer. Metastatic triple-negative breast cancer is often treated with a range of chemotherapy agents and immunotherapy.

Metastatic breast cancer survival rate

Median overall survival for metastatic breast cancer varies by subtype and ranges from two to five years. Hormone receptor-positive cancers often have the best prognosis.

Additionally, factors such as the presence of visceral metastases (soft tissue lesions), brain metastases and multiple metastatic sites all confer worse prognosis, whereas a better performance status, younger age at diagnosis, bone-only metastatic disease, and longer disease-free interval between initial diagnosis and development of metastatic recurrence all improve prognosis.

Advances in metastatic breast cancer

Due to advances in clinical trials and the discovery of new treatments, the prognosis for metastatic breast cancer continues to improve, although there is no cure. Continued research and advocacy will undoubtedly continue to advance how doctors can better support patients diagnosed with metastatic breast cancer.

Living with metastatic breast cancer can be challenging, but your doctor can help you determine the best method of treatment to improve your overall prognosis.

By Jessica Daniels, BDO Staff Writer | Published June 26, 2023