For ARF, three risk factors were used to stratify the risk groups: patient age, tumor size, and biological subtype. Of 1,656 analyzable patients (172, unknown), 748 (45.2%) had no risk factors and 694 (41.9%), 194 (11.7%), and 20 (1.2%) patents had one, two, and three risk factors, respectively. Because of the small number of patients with three risk factors, patients with two to three risk factors were assigned to the high-risk group (214, 12.9%). The 5-year cumulative ARF rates were 2.8% with no risk factors, 5.9% with one risk factor, and 14.7% with two to three risk factors. The 7-year cumulative ARF rates were 3.9% with no risk factors, 8.4% with one risk factor, and 15.7% with two to three risk factors (Figure 2). The 10-year cumulative ARF rates were 3.9% with no risk factors, 10.6% with one risk factor, and 18.1% with two to three risk factors.