Final answer:
Testicular cancer and prostate cancer are the leading killers in young men. Lung cancer causes the most cancer deaths in young men.
Step-by-step explanation:
Testicular cancer is the most common cancer in males between the ages of 20 and 39 years, making it one of the leading killers in young men. It is more common in males of European than African ancestry. Possible signs and symptoms include a lump or swelling in one testis, fluid in the scrotum, and testicular pain or tenderness.
Prostate cancer is also a leading killer in young men. It is the most common type of cancer in men and makes up about one third of all cancers in men. Regular screenings and early detection can increase the chances of successful treatment.
Lung cancer, although not the most common type of cancer in young men, causes the most cancer deaths due to its high mortality rate. Exposure to tobacco smoke is the primary cause of lung cancer.