Cancer may lead to pain, weight loss, fatigue, or obstruction of visceral organs. Death typically occurs as a result of inanition and organ failure. Most cancer deaths are due to metastases rather than the primary cancer.
Pain in patients with cancer frequently results from bone metastases, nerve or plexus involvement, or pressure exerted by a tumor mass or effusion. Aggressive pain management is essential in the treatment of cancer and for maintenance of quality of life.
Pleural effusions should be drained if symptomatic and monitored for reaccumulation. If the effusion reaccumulates rapidly, thoracostomy tube drainage and sclerosing agents or repeated catheter drainage should be considered.
Spinal cord compression can result from cancer spread to the vertebrae and requires immediate surgery or radiation therapy. Symptoms may include back pain, lower extremity paresthesias, and bowel and bladder dysfunction. Diagnosis is confirmed by CT or MRI.
Venous thrombosis (clots in the veins) in the lower extremities leading to pulmonary emboli are frequent in patients with pancreatic, lung, and other solid tumors and in patients with brain tumors. Tumors produce procoagulants, such as tissue factor, leading to excess clot formation, particularly in patients undergoing surgery.
Metabolic and immune consequences of cancer can include hypercalcemia, hyperuricemia, increased ACTH production, antibodies that produce neurologic dysfunction, hemolytic anemia, and many other paraneoplastic complications.