The National Cancer Institute estimated that breast cancer would lead to over 190,000 new cases diagnoses and over 40,000 deaths in the United States in 2009 alone. Breast cancer develops from mutated cells within any of the tissues of the breast, which begin to divide uncontrollably to form a tumor. As the cancer progresses, the tumor cells gain the ability to break away from the initial tumor, migrate throughout the body, and form secondary tumors in distant tissues--a process known as metastasis. Breast cancer commonly metastasizes to the lungs, according to the University of Rochester. This can lead to the development of fatal secondary tumors.
Shortness of Breath
One of the first symptoms of the development of secondary cancers in the lungs is shortness of breath. Normally, the lungs have a specific capacity for air. The lungs' air capacity can be increased by exercise and decreased by factors such as smoking, but these changes occur gradually. As lung cancer develops, the tumor quickly begins to take up space in the lung, decreasing the amount of air the lungs can process and giving the patient a constant feeling that she is short of breath.
Shortness of breath alone is not sufficient to diagnose lung metastases from breast cancer, but rapid changes in breathing require medical attention to rule out the possibility of metastasis.
Coughing up Bloody Sputum
Another symptom of lung cancer metastases as a result of breast cancer is coughing up bloody sputum. As the cancer cells divide and and tumor within the lungs grows, neighboring tissue is damaged. Cancer cells actively kill neighboring healthy tissue in order to make room for further tumor growth, which leads to damage of the lung tissue and bleeding. Blood collection in the lung signals for coughing to remove the excess fluid, so patients will begin to cough up blood. Patients with a history of breast cancer must seek immediate medical attention if they develop this side effect, to address the possibility of lung metastasis.
Chest Pain
Another commonly experienced symptom of lung metastasis as a result of breast cancer is chest pain. The chest cavity contains the lungs and heart, and the organs are surrounded by the ribcage and supported by the diaphragm, the muscle that separates the chest and abdomen. As the lung tumor grows, the cancer begins to increase pressure within the chest cavity, damaging neighboring tissue and leading to chest pain, or pain in the rib cage. Since chest pain may be cause by a range of disorders, patients experiencing chest pain should discuss their concerns with their doctor to test the possibility of cancer in the lungs.
