The cancer that arises in the lung is called lung cancer. It can be of two kinds- small-cell and non-small-cell lung carcinoma. It is caused by long-term tobacco smoking, exposure to radon gas, second-hand smoke, asbestos and other forms of air pollution. Lung cancer can be prevented by avoiding smoking and exposure to air pollution. It usually arises due to a genetic damage to DNA and epigenetic changes. These changes affect the normal functions of the cell such as cell proliferation, DNA repair and programmed cell death. The lungs are commonly affected by the spread of cancer arising in other parts of the body. Primary lung cancers commonly metastasize to the bones, brain, liver and adrenal glands. The current research dimensions in lung cancer treatment include immunotherapy, epigenetics, and combinations of radiotherapy and chemotherapy. This book is compiled in such a manner, that it will provide in-depth knowledge about the assessment, diagnosis and treatment of lung cancer. It includes some of the vital pieces of work being conducted across the world, on various topics related to lung cancer. It includes contributions of experts and scientists, which will provide innovative insights into this disease.