Non-small cell carcinoma is a more common form of lung cancer, accounting for roughly 80-85% of all cases of lung cancer. This form of cancer, just like small cell carcinoma, originates in the lung and spreads from the lung to the mediastinum (space between the lungs) and from there, the cancer can spread into the bloodstream. Non-small carcinoma is generally far more treatable than small cell carcinoma and the five-year survival rate can be excellent when the cancer is discovered in its early stages.