Lung cancer mainly occurs in older people. About 2 out of 3 people diagnosed with lung cancer are 65 or older; fewer than 2% of all cases are found in people younger than 45. The average age at the time of diagnosis is about 70.urvival statistics based on the stage of the cancer are discussed in the section â Non-small cell lung cancer survival rates by stage .â. Despite the very serious prognosis (outlook) of lung cancer, some people with earlier stage cancers are cured.