When does breast cancer metastasize to the brain? Details explored as actress Suzanne Somers’ official cause of death is revealed

Actress and author Suzanne Somers passed away on Sunday, October 15 after battling with breast cancer. She was 76 years old. Somers' publicist, R. Couri Hay, said in a statement that she passed away after a 23-year-long battle with "aggressive breast cancer". Somers was well known for her roles in television series such as Three's Company and Step by Step.

A death certificate obtained by The Blast revealed that Suzanne Somers had died from "breast cancer with metastasis to the brain". The report also revealed that she was suffering from hypertension and hydrocephalus. Breast cancer can metastasize to the brain when the cancer cells spread from the original affected location to the brain and can result in the formation of one or multiple brain tumors.

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Breast cancer with metastasis to the brain explained

The National Cancer Institute defines metastasis as the process in which cancer cells spread to other parts of the body, away from where they originally originated. According to the Moffit Cancer Center, the spread or metastasis of breast cancer is also called "secondary breast cancer in the brain."

Healthline explains that this situation is caused by cancer cells breaking away from the original site of the tumor (in this case, the breast), traveling through the lymphatic, or circulatory system, and eventually arriving at the brain to create or establish new tumors.

This condition is not to be confused with brain cancer. The Moffit Cancer Center specifies that brain cancer is caused due to cancerous brain cells that form tumors. However, breast cancer with metastasis to the brain involves cancerous breast cells that form tumors in the brain.

Symptoms of this include dizziness, issues with balance, paralysis on one side of the body, headaches, numbness, blurred or double vision, a complete loss of vision, seeing light flashes, headaches, nausea, vomiting, seizures, strokes, memory loss, impaired judgment, and mood, personality, or behavior changes.

According to Healthline, the diagnosis starts with blood tests, including a metabolic panel assessment, complete blood count, and tests for breast cancer tumor markers. Confirmation of the diagnosis is done through a head MRI with the help of a contrast solution.

There are certain risk factors that increase the chances of metastasis to the brain. Women diagnosed with breast cancer before 35 run a higher risk of brain metastasis. Breast tumours greater than 2 cm and positive lymph nodes at the time of diagnosis are additional risk factors.

The different types of breast cancer also have different levels of risk for metastasis. Women with triple-negative breast cancer and HER2-positive breast cancer have a higher risk for metastasis.

Treatments for metastasis to the brain are split between local and systemic treatments. A smaller number of easily accessible brain metastases in a healthy person can be removed through surgery. Other local treatments include Stereotactic radiosurgery and lastly, Whole-brain radiation. Systemic treatments include Hormone therapy, which is often paired with Targeted therapy, and finally, Immunotherapy.

Around 10-15% of women with stage 4 breast cancer will experience metastasis of the cancer to the brain. Metastasis can not only happen to the brain but to different parts of the body as well. Sometimes, the cancer directly spreads to the brain, other times it spreads to another body part like the lungs or bones and from there, indirectly spreads to the brain.