Table 1. Patient characteristics.

Characteristics	N (%)
Age (years)
≤65	190 (37.70)
>65	305 (60.52)
Unknown	9 (1.78)
Gender
Female	131 (25.99)
Male	373 (74.01)
T
1	114 (22.62)
2	295 (58.53)
3	71 (14.09)
4	24 (4.76)
N
0	320 (63.49)
1	133 (26.39)
2	40 (7.94)
3	5 (0.99)
Unknown	6 (1.19)
M
0	414 (82.14)
1	7 (1.39)
Unknown	83 (16.47)
Stage
I	245 (48.61)
II	163 (32.34)
III	85 (16.87)
IV	7 (1.39)
Unknown	4 (0.79)
Total	504 (100.00)

T, tumor; N, node; M, metastasis.