One - , 3 - , and 5-year recurrence-free survival rates in patients with small-diameter tumors ( 5 cm ) were 88.8 % , 67.4 % , 42.9 % in the adjuvant RT group and 82.3 % , 42.9 % , 21.5 % in the control group ( p = 0.03 , log-rank test ) .