Breast cancer can spread to the stomach, a process known as metastasis. This occurrence is uncommon. This article provides information on how this specific type of metastasis happens, its symptoms, and how it is diagnosed and treated.
Understanding How Cancer Spreads
Cancer spreads when malignant cells break away from the primary tumor and travel to other parts of the body, forming new tumors. This process is called metastasis. Cancer cells can use several pathways to move from their original site to distant locations.
One common pathway is through the bloodstream, known as hematogenous spread. Cancer cells can invade blood vessels, enter the circulation, and then be carried to various organs throughout the body. Another route is the lymphatic system, a network of vessels and nodes that are part of the body’s immune system. Cancer cells can break off, enter lymphatic vessels, and travel to nearby or distant lymph nodes, eventually reaching other organs.
When Breast Cancer Affects the Stomach
When breast cancer metastasizes to the stomach, it involves cancer cells traveling from the breast to the gastric lining. This type of spread is relatively rare, with reported incidences varying. The time between initial breast cancer diagnosis and detection of gastric metastasis can range from a few months to several years.
Gastric metastasis from breast cancer is most frequently associated with invasive lobular breast cancer (ILC), accounting for a high percentage of cases. This differs from invasive ductal carcinoma, which more commonly metastasizes to sites like the liver, lungs, and brain. Cancer cells can arrive at the stomach through the bloodstream, lymphatic spread, or, less commonly, direct invasion from surrounding tissues. Once in the stomach, these metastatic cells can infiltrate the stomach wall, often leading to a diffuse thickening known as linitis plastica, which can be challenging to distinguish from a primary stomach cancer.
Symptoms to Be Aware Of
Symptoms of breast cancer that has spread to the stomach can be varied and often resemble those of other gastrointestinal conditions. Common symptoms include nausea and vomiting. Individuals may also experience abdominal pain or discomfort.
A feeling of early satiety, meaning feeling full quickly after eating only a small amount of food, is another frequently reported symptom. Unexplained weight loss and a general loss of appetite can also occur. Less commonly, difficulty swallowing (dysphagia) or gastrointestinal bleeding may be present. These symptoms are not exclusive to metastatic breast cancer and can be caused by many other less serious conditions. However, if a person with a history of breast cancer experiences these symptoms, medical evaluation is recommended.
Confirming and Treating the Spread
Confirming breast cancer metastasis to the stomach involves a combination of diagnostic procedures. An endoscopy with biopsy is a primary method, where a thin, flexible tube with a camera is inserted into the esophagus and stomach to visualize the lining and collect tissue samples. Since breast cancer cells often infiltrate deeper layers of the stomach wall, multiple and deep biopsies are sometimes necessary for an accurate diagnosis, as superficial biopsies may miss the metastatic cells.
Imaging tests, such as CT scans or PET scans, are also used to identify areas of thickening in the stomach wall and to assess for other sites of metastasis in the body. Immunohistochemistry, a laboratory technique that uses antibodies to detect specific markers on cells, is important for differentiating metastatic breast cancer from a primary stomach cancer. Markers like estrogen receptor (ER), progesterone receptor (PR), CK7, and GATA3 are often positive in breast cancer cells, while CK20 is typically negative, helping to confirm the breast origin.
Treatment for breast cancer that has spread to the stomach is generally systemic, aiming to control the cancer throughout the body rather than just at the stomach site. These systemic therapies may include chemotherapy, hormonal therapy, targeted therapy, and immunotherapy. Surgical intervention for gastric metastasis is typically reserved for managing complications like obstruction or bleeding, as gastric metastasis indicates systemic disease. Treatment plans are highly individualized, taking into account the cancer’s characteristics, previous treatments, and the patient’s overall health.