Table 1: Patient characteristics classified by age.

Variable Age < 75 years (n = 38) Age ≥ 75 years (n = 9) p values
Median (range) age, years 62 (37-74) 77 (75-84) < 0.0001
Male/female, (%) 76/24 90/10 0.4073
Hypertension, n (%) 20 (53) 6 (67) 0.4463
Diabetes mellitus, n (%) 8 (22) 2 (22) 0.9386
Smoking history, n (%) 21 (55) 5 (56) 0.8467
Prior nephrectomy, n (%) 15 (39) 4 (44) 0.7847
ECOG PS, n (%)
0 21 (55) 3 (33) 0.2073
1 9 (24) 5 (56)
≥ 2 6 (16) 1 (11)
Missing (unknown) 2 (5) 0 (0)
Risk factors based on MSKCC data, n (%)
0 (favorable) 4 (11) 0 (0) 0.2161
1-2 (intermediate) 21 (55) 8 (89)
≥ 3 (poor) 11 (29) 1 (11)
Missing 2 (5) 0 (0)
Common site of metastasis, n (%)
Lung 21 (55) 6 (67) 0.5338
Bone 11 (29) 3 (33) 0.7959
Lymph nodes 10 (26) 3 (33) 0.6722
Histology, n (%)
Clear cell 19 (50) 6 (67) 0.3384
Others 3 (8) 0 (0)
Missing (untraced or unknown) 16 (42) 3 (33)
Initial doses of sunitinib, n (%)
50 mg 0.1483*
4 weeks on, 2 weeks off 27 (70) 5 (56)
2 weeks on, 1 weeks off 3 (8) 0 (0)
37.5 mg
4 weeks on, 2 weeks off 6 (16) 3 (33)
2 weeks on, 1 weeks off 0 (0) 1 (11)
25 mg
4 weeks on, 2 weeks off 1 (3) 0 (0)
2 weeks on, 1 weeks off 1 (3) 0 (0)
Relative dose intensity, (%)
Median 75 68.8 0.7559
Mean ± SD 72.5 ± 19.4 70.4 ± 15.9 0.8105
Clinical outcome of sunitinib treatment, n (%)
Continuing sunitinib 3 (8) 0 (0) 0.3837
Discontinuing sunitinib 35 (92) 9 (100)
Reason for discontinuation (n = 42)
Lack of efficacy 17 (44) 6 (67)
Progressive disease 16 (41) 5 (56)
Stable disease with increasing tendency 1 (3) 0 (0)
Death 0 (0) 1 (11) 0.5019
Adverse events 15 (40) 3 (33)
Others 3 (8) 0 (0)

All statistical analysis was carried out except for missing data. Mean and median relative dose intensity (%) was calculated during the first 6 weeks of treatment. *50 mg vs. ≤ 37.5 mg; p = 0.1787.

Abbreviations: ECOG PS: Eastern Cooperative Oncology Group Performance Status; MSKCC: Memorial Sloan-Kettering Cancer Center; SD: Standard Deviation.