Lung cancer is a malignant tumor that develops in the lungs, and is one of the most common and deadliest forms of cancer. Symptoms of lung cancer can range from a persistent cough, chest pain, shortness of breath, and a hoarse voice. Diagnosis is usually done through a chest X-ray, CT scan, or biopsy. Treatment options include chemotherapy, radiation, and surgery. For early-stage cancers, surgery may be the only treatment necessary, while advanced-stage cancers may require a combination of treatments. It is important to seek medical advice as early as possible to ensure the best possible outcome.