| Non-ccRCC (N=24) | ccRCC (N=45) | |
|---|---|---|
| Age (years) | 57.9 (17.6) | 61.8 (10.7) |
| Tumor size (cm) | 7.8 (3.2) | 7.7 (3.2) |
| pT Stage | 3.7 (1.4) | 4.4 (2) |
| Sex - F | 7 (29.2%) | 16 (35.6%) |
| Sex - M | 17 (70.8%) | 29 (64.4%) |
| pN Stage - 0 | 1 (4.2%) | 14 (31.1%) |
| pN Stage - 1 | 0 (0%) | 4 (8.9%) |
| pN Stage - NA | 23 (95.8%) | 27 (60%) |
| M Stage - 0 | 7 (29.2%) | 29 (64.4%) |
| M Stage - 1 | 1 (4.2%) | 8 (17.8%) |
| M Stage - NA | 16 (66.7%) | 8 (17.8%) |
| Overall Stage - 1 | 2 (8.3%) | 9 (20%) |
| Overall Stage - 2 | 4 (16.7%) | 3 (6.7%) |
| Overall Stage - 3 | 2 (8.3%) | 15 (33.3%) |
| Overall Stage - 4 | 1 (4.2%) | 9 (20%) |
| Overall Stage - NA | 15 (62.5%) | 9 (20%) |
| Rhabdoid features - 0 | 5 (20.8%) | 18 (40%) |
| Rhabdoid features - 1 | 0 (0%) | 11 (24.4%) |
| Rhabdoid features - NA | 19 (79.2%) | 16 (35.6%) |
| Sarcomatoid features - 0 | 7 (29.2%) | 31 (68.9%) |
| Sarcomatoid features - 1 | 1 (4.2%) | 4 (8.9%) |
| Sarcomatoid features - NA | 16 (66.7%) | 10 (22.2%) |
| Necrosis - 0 | 0 (0%) | 18 (40%) |
| Necrosis - 1 | 8 (33.3%) | 18 (40%) |
| Necrosis - NA | 16 (66.7%) | 9 (20%) |
| Tumor grade - 2 | 3 (12.5%) | 10 (22.2%) |
| Tumor grade - 3 | 2 (8.3%) | 12 (26.7%) |
| Tumor grade - 4 | 2 (8.3%) | 14 (31.1%) |
| Tumor grade - NA | 17 (70.8%) | 9 (20%) |
| Microvascular invasion - 0 | 5 (20.8%) | 19 (42.2%) |
| Microvascular invasion - 1 | 2 (8.3%) | 11 (24.4%) |
| Microvascular invasion - NA | 17 (70.8%) | 15 (33.3%) |
| Reader 1 | 3 (1.2) | 4 (0.7) |
| Reader 2 | 2.2 (1.4) | 3.1 (1.4) |
| Reader 3 | 2.2 (1.2) | 4.1 (0.9) |
Tumor scoring
Patient characteristics
Patient/lesion characteristics are summarized in Table 1 comparing ccRCC to non-ccRCC (pRCC, chrRCC, oncocytoma, and AML). Quantitative variables are summarized by mean (SD) and categorical variables by N (%). In particular, reader scores tend to be higher in ccRCC than in non-ccRCC.
The same table with missing categories removed:
| Non-ccRCC (N=24) | ccRCC (N=45) | |
|---|---|---|
| Age (years) | 57.9 (17.6) | 61.8 (10.7) |
| Tumor size (cm) | 7.8 (3.2) | 7.7 (3.2) |
| pT Stage | 3.7 (1.4) | 4.4 (2) |
| Sex - F | 7 (29.2%) | 16 (35.6%) |
| Sex - M | 17 (70.8%) | 29 (64.4%) |
| pN Stage - 0 | 1 (100%) | 14 (77.8%) |
| pN Stage - 1 | 0 (0%) | 4 (22.2%) |
| M Stage - 0 | 7 (87.5%) | 29 (78.4%) |
| M Stage - 1 | 1 (12.5%) | 8 (21.6%) |
| Overall Stage - 1 | 2 (22.2%) | 9 (25%) |
| Overall Stage - 2 | 4 (44.4%) | 3 (8.3%) |
| Overall Stage - 3 | 2 (22.2%) | 15 (41.7%) |
| Overall Stage - 4 | 1 (11.1%) | 9 (25%) |
| Rhabdoid features - 0 | 5 (100%) | 18 (62.1%) |
| Rhabdoid features - 1 | 0 (0%) | 11 (37.9%) |
| Sarcomatoid features - 0 | 7 (87.5%) | 31 (88.6%) |
| Sarcomatoid features - 1 | 1 (12.5%) | 4 (11.4%) |
| Necrosis - 0 | 0 (0%) | 18 (50%) |
| Necrosis - 1 | 8 (100%) | 18 (50%) |
| Tumor grade - 2 | 3 (42.9%) | 10 (27.8%) |
| Tumor grade - 3 | 2 (28.6%) | 12 (33.3%) |
| Tumor grade - 4 | 2 (28.6%) | 14 (38.9%) |
| Microvascular invasion - 0 | 5 (71.4%) | 19 (63.3%) |
| Microvascular invasion - 1 | 2 (28.6%) | 11 (36.7%) |
| Reader 1 | 3 (1.2) | 4 (0.7) |
| Reader 2 | 2.2 (1.4) | 3.1 (1.4) |
| Reader 3 | 2.2 (1.2) | 4.1 (0.9) |
Inter-rater agreement
Table 3 shows the intra-class correlation coefficients between the three readers both on the original 5-point scale and grouped 3-point scale (1-2, 3, 4-5). Both show similar moderate agreement.
| Scale | ICC | 95% CI | P |
|---|---|---|---|
| 5-point | 0.394 | (0.228, 0.557) | <0.001 |
| 3-point | 0.365 | (0.199, 0.532) | <0.001 |
ccRCC vs score
Table 4 and Table 5 summarize the mean (SD) of 5- and 3-point reader scores and their average comparing ccRCC with non-ccRCC, with P values generated by the Wilcoxon rank sum test. In most cases, ccRCC has a significantly higher score than non-ccRCC.
| Non-ccRCC | ccRCC | P | |
|---|---|---|---|
| Reader 1 | 3 (1.2) | 4 (0.7) | 0.001 |
| Reader 2 | 2.2 (1.4) | 3.1 (1.4) | 0.028 |
| Reader 3 | 2.2 (1.2) | 4.1 (0.9) | <0.001 |
| Reader Avg | 2.9 (1) | 3.8 (0.8) | 0.003 |
| Non-ccRCC | ccRCC | P | |
|---|---|---|---|
| Reader 1 | 2.2 (0.8) | 2.8 (0.4) | 0.001 |
| Reader 2 | 1.7 (0.9) | 2.1 (0.8) | 0.079 |
| Reader 3 | 1.5 (0.7) | 2.7 (0.6) | <0.001 |
| Reader Avg | 2 (0.7) | 2.6 (0.5) | 0.006 |
Correlation of reader scores with other variables
Quantitative variables
For pT stage, Overall stage, tumor size, and tumor grade, we fit a linear regression model against each reader score and reader-averaged score. Figure 1 – Figure 4 show the results. Most relationships are non-significant.
Binary variables
For binary variables, we plot a boxplot of reader scores for each group and test the scores between groups by the Wilcoxon rank sum test. Figure 5 – Figure 10 show the results. Most relationships are non-significant, except for necrosis vs Reader 1.
