Table 1.
Baseline clinicopathological characteristics of the 153 patients with mRCC stratified by baseline serum IgG levels.
| Variable | Overall (n=153) | Normal IgG (n=126) | Elevated IgG (n=27) | P value |
|---|---|---|---|---|
| Age, years (IQR) | 59 (54–65) | 59.5 (54–65) | 59 (55.5–65) | 0.872 |
| Male, n (%) | 119 (77.8) | 102 (81.0) | 17 (63.0) | 0.124 |
| T stage, n (%) | 0.103 | |||
| T1–2 | 77 (50.3) | 67 (53.2) | 10 (37.0) | |
| T3–4 | 76 (49.7) | 59 (46.8) | 17 (63.0) | |
| N1 stage, n (%) | 28 (18.3) | 25 (19.8) | 3 (11.1) | 0.429 |
| ≥2 metastatic sites, n (%) | 56 (36.6) | 46 (36.5) | 10 (37.0) | 0.959 |
| IMDC risk group, n (%) | 0.022 | |||
| Favorable | 36 (23.5) | 35 (27.8) | 1 (3.7) | |
| Intermediate | 91 (59.5) | 72 (57.1) | 19 (70.4) | |
| Poor | 26 (17.0) | 19 (15.1) | 7 (25.9) | |
| Baseline IgG, g/L (IQR) | 13.29 (11.30–15.90) | 12.50 (10.93–14.33) | 20.43 (18.00–23.80) | – |
Continuous variables are presented as median (interquartile range [IQR]) and were compared using the Mann–Whitney U test. Categorical variables are presented as number (%) and were compared using the χ² test or Fisher’s exact test, as appropriate. Baseline serum IgG was used to define the study groups; therefore, no statistical comparison was performed.
IMDC, International Metastatic Renal Cell Carcinoma Database Consortium; IgG, immunoglobulin G; IQR, interquartile range.