Signs and symptoms of lung cancer
Paraneoplastic syndromes are patterns of organ dysfunction related to immune-mediated or secretory effects of neoplasms. In this case, lung cancer cells start to produce hormone-like substances which go into the blood stream and reach distant places. These syndromes occur in 10–20% of lung cancer patients. They may precede, accompany, or follow the diagnosis of lung cancer.
In patients with small cell carcinoma, the syndrome of inappropriate antidiuretic hormone (SIADH) can develop in 10–15%; in those with squamous cell carcinoma, hypercalcemia can develop in 10%. High calcium in the blood can result in frequent urination, increased thirst, constipation, dizziness, and confusion. Cerebellar degeneration can occur leading to trouble in maintaining balance, difficulty in swallowing, or speaking.
Cushing syndrome develops when cancer cells make ACTH, a hormone that causes the adrenal glands to make cortisol. This can lead to symptoms such as weight gain, easy bruising, weakness, drowsiness, and fluid retention. Cushing syndrome can also cause high blood pressure, high blood sugar levels, or even diabetes. Their recognition is important because treatment of the primary tumor may improve or resolve symptoms, even when the cancer is not curable.