Metastasized

Metastasized describes cancer that has spread from its original site (the primary tumor) to distant parts of the body. Metastasis is a multistep process in which cancer cells detach, invade surrounding tissue, enter the bloodstream or lymphatic system, survive transport, exit at distant sites, and establish new tumors called metastases. These metastatic tumors are composed of cancer cells related to the primary tumor but may interact differently with the surrounding tissue environment.

Spread occurs mainly via the lymphatic system or the bloodstream, and in some cancers cells can seed body cavities. The distribution of metastases is influenced by the tissue of origin and tumor biology. Common metastatic sites include bones, liver, lungs, and brain, with different cancers showing characteristic patterns (for example, breast cancer often to bone and liver; colorectal cancer to liver; prostate cancer to bone).

Diagnosis generally relies on imaging studies such as CT, MRI, or PET scans, biopsy of metastatic lesions, and sometimes tumor markers or molecular profiling. The presence of distant metastasis generally corresponds to stage IV disease in many cancer types, informing prognosis and treatment planning.

Treatment for metastasized cancer is typically systemic, aiming to control disease, relieve symptoms, and prolong survival, and may include chemotherapy, hormonal therapy, targeted therapy, immunotherapy, and radiation. Local therapies may be used for symptom relief or control of specific sites, such as palliative radiation to bone lesions or surgery for isolated metastases when appropriate. Prognosis varies widely by cancer type, extent of spread, patient factors, and available therapies; some cancers respond well to targeted treatments, while others remain difficult to control.