How can one tell if cancer has metastasized?

Studies or symptoms.: The extent of disease & metastasis are often important factors is determining treatment & prognosis. This is often assessed by imaging studies : x-rays, ct scans, mri, pet, and nuclear studies. For patients who present with metastatic disease, signs & symptoms of metastasis may exist. Lung mets can present with cough, brain mets with neurologic symptoms. Others present with pain or palpable mass.