Paraneoplastic Syndromes and Cancer Cachexia

Key points

• • Paraneoplastic syndromes are disorders caused by a cancer at a site away from the tumour or its spread, often from hormones or antibodies it produces.
• • Examples include a high blood calcium from a parathyroid-like hormone, and a low blood sodium from inappropriate ADH secretion, often with lung cancer.
• • Cushing's syndrome can result from a tumour making ACTH, and some cancers cause nerve and muscle disorders through antibodies.
• • Cancer cachexia is the wasting of fat and muscle with weight loss, weakness and poor appetite, driven by inflammatory signals rather than starvation alone.
• • These syndromes can be the first clue to a hidden cancer, appearing before the tumour itself is found.