While nonsmall-cell lung cancer is the most common form of lung cancer, small-cell lung cancer only affects approximately 10 to 15 percent of patients, according to Healthline. Small-cell lung cancer usually begins in the bronchi or in the middle of the chest and tends to spread to other body parts much quicker than nonsmall-cell lung cancer.
Nonsmall-cell lung cancer patients go through four stages of the medical conditions, while small-cell lung cancer patients experience two stages, according to WebMD. During the first stage of nonsmall-cell lung cancer, the cancer is contained in the lung. In the second and third stages, the disease is found in the lung and possibly the lymph nodes as well. It finally spreads outside the lung and reaches the other parts of the body during the fourth stage of the disease. Small-cell lung cancer patients go through a limited stage, where the cancer is contained in its original area, and then an extensive stage, where the cancer spreads toward other body parts.
Small-cell lung cancer responds better to chemotherapy compared to nonsmall-cell lung cancer, according to LungCancer.org. Small-cell lung cancer also grows rapidly during its early stages and is reportedly uncommon with nonsmokers.
Small-cell lung cancer is most often discovered after the disease has spread extensively across the body, reports WebMD. It is known as the most aggressive form of lung cancer due to how rapidly it grows and metastasizes to other areas within the body.