In 2002, the total cost in the United States for initial cancer care was $6.7 billion. Over the course of the study, the average cost for treating a lung cancer patient went up $7,139, to an average of $39,891. With prostate cancer, the average price tag for treatment went up $5,345, to an average of $41,134. The cost of treating breast cancer went up $4,189, to an average cost of $20,964.