Each year, more than 140,000 Americans are diagnosed with colorectal cancer, according to the American Cancer Society. The second leading cause of cancer-related deaths in the United States, colorectal cancer starts in either the colon or the rectum and affects men slightly more than women. The lifetime risk for developing colorectal cancer is about 1 in 20 (5.1 percent). This year, colorectal cancer is expected to cause nearly 50,000 deaths.