Overview of Breast Cancer (metastatic)
Breast cancer is cancer that develops from breast tissue. Worldwide, breast cancer is the most frequently diagnosed fatal cancer in women and the leading cause of cancer death among women. Metastatic breast cancer is the stage of breast cancer where the disease has been spread to distant sites beyond the axillary lymph nodes. It is also known as advanced breast cancer or stage 4 breast cancer. There is no cure for metastatic breast cancer. It usually occurs several years after the primary breast cancer. Metastatic cells have developed resistance to several lines of previous treatment and acquire special properties to metastasize to distant sites. Breast cancer can metastasize anywhere in body but primarily metastasizes to bone, lungs, regional lymph nodes, liver and brain, with the most common site being the bone.
Causes and Risk Factors of Breast Cancer (metastatic)
Risk factors for developing breast cancer include obesity, lack of physical exercise, alcoholism, hormone replacement therapy during menopause, radiotherapy, and early age at first menstruation, having children late or not at all, older age, and family history. About 5–10% of cases are due to genes inherited from a person's parents, including BRCA1 and BRCA2 among others. The common markers for breast cancer metastasis prognosis include tumor size, axillary lymph node status, histological grade, angioinvasion, uPA/PA11 protein level, steroid receptor expression, ERBB2 gene amplification and protein expression and gene expression profiling.
Signs and Symptoms of Breast Cancer (metastatic)
The symptoms of metastatic breast cancer depend upon the location of metastasis. Bone metastasis cause severe, progressive pain, pathological fracture, and erythema over the affected bone and swelling. Brain metastasis is manifested as persistent, gradually worsening headache, seizures, nausea or vomiting, vertigo, visual problems, behavioral and personality changes, and increased intracranial pressure. Metastasis to liver can cause nausea, vomiting, jaundice, abdominal pain, loss of appetite and elevated enzyme level. Metastasis to lung can cause cough, dyspnea and chest pain. Other nonspecific systemic symptoms include fatigue, malaise, weight loss, and poor appetite.