Breast cancer that has spread to the liver represents a late-stage diagnosis known as metastatic breast cancer, or stage 4. This condition occurs when cancer cells leave the original tumor site in the breast tissue and travel to distant organs, including the liver, brain, or bones. Although the diagnosis changes to reflect the location of the spread, the cancer remains classified as breast cancer rather than a new type of liver disease. The liver is the third most common site for this spread, following the lungs and bones.
Metastasis happens when cancerous cells grow beyond the initial tumor location. While research suggests a person’s liver environment might make it more susceptible to these cells, the exact mechanics of how breast cancer specifically targets the liver remain unclear. Factors that may influence this risk include age, menopausal status, the number of lymph nodes affected, and tumor size. The “seed and soil” hypothesis proposes that cancer cells and the liver must be compatible for this spread to occur, though scientists have not yet defined all the biological rules governing this process.
Related: Mediterranean diet linked to longer lives
Screening practices have evolved to catch these secondary tumors earlier. When doctors find liver metastasis sooner, the outlook generally improves because the tumor is discovered before symptoms appear. A routine liver function test uses a blood sample to measure the levels of liver enzymes and proteins, often revealing issues before a physical exam would.
Early-stage treatments focus on removing or destroying the cancer entirely. However, when cancer reaches the liver, doctors shift their strategy. The goal becomes slowing tumor growth and improving the patient’s quality of life. Systematic medications, such as immunotherapy, chemotherapy, hormone therapy, and targeted drugs, serve as the primary line of defense. A doctor might recommend a combination of these therapies, along with radiation or surgery in specific situations. The choice of treatment depends heavily on the size of the liver tumor, previous treatments received, whether the cancer has spread to other organs, and the patient’s overall health.
Related: Smart Eating for Active People
It is common for treatment to be less aggressive than in earlier stages. If symptoms become unmanageable or the side effects outweigh the benefits, a person may choose to discontinue active treatment. In these cases, the focus shifts to managing symptoms and preparing for end-of-life care.
Metavivor, an organization dedicated to researching MBC, states that 1 in 8 women will develop breast cancer during their lifetime. Of those, about 1 in 3 will experience metastasis. For men, about 1 out of 1,000 will develop breast cancer during their life, but under 2% will experience metastasis. There is currently no cure for MBC, so treatment usually focuses on slowing the growth of the tumor and improving a person’s quality of life. Treatment can also help increase the person’s lifespan. Someone with MBC that has spread to the liver may live for several more years with successful treatment. Treatment tends to focus on slowing the growth and spread as well as managing the symptoms.