Cancer remains a leading cause of death worldwide, with an estimated 1,658,370 new cancer cases and 589,430 cancer deaths in the United States in 2015. Lung cancer causes the most cancer deaths each year in both men and women, though the lung cancer death rates have been declining since 1990 in men and since 2002 in women. Overall cancer death rates have declined by 23% from their peak in 1991, resulting from fewer smoking, advances in early detection and treatment.