OS was additionally analyzed according to the number of risk factors present. In patients with one, two, and three risk factors (a–c), MSTs of the resection and non-resection groups were 20.3 vs. 10.0 (p<0.001), 16.9 vs. 5.5 (p<0.001), and 14.1 vs. 7.6 months (p=0.032), respectively. In patients who underwent surgical resection, there was no significant difference in survival among the patients with one, two, and three risk factors (p=0.46).