Tumor size improves the accuracy of TNM predictions in patients with renal cancer.
OBJECTIVE
Current staging for renal cancer (RC) does not directly rely on tumor size. We examined the increment in accuracy related to inclusion of pathologically determined tumor size in prediction of nodal metastases (N+), distant metastases (M+), and cancer-specific survival (CSS).


METHODS
Partial or radical nephrectomy was performed in 2245 patients with clear cell histology. Pathologic stages were T1a in 566, T1b in 490, T2 in 303, T3 in 831, and T4 in 55 patients. Tumor size was 0.5-25 cm (mean, 6.8). Multivariate models relied on 1997 and 2002 TNM variables and addressed N+, M+ disease, and CCS. Their accuracy was compared according to either the presence or absence of tumor size.


RESULTS
In all univariate and multivariate models, tumor size was a statistically significant predictor of all outcomes (p< or =0.001). In all multivariate models, tumor size added between 3.7% and 0.8% to predictive accuracy of either 1997 or 2002 TNM categories.


CONCLUSIONS
Tumor size represents a highly significant, multivariate, and informative predictor of RC outcomes and may warrant inclusion in future TNM revisions.
Karakiewicz
Pierre I
PI
Cancer Prognostics and Health Outcomes Unit, University of Montreal, Montreal, Que., Canada. pierre.karakiewicz@umontreal.ca
Lewinshtein
Daniel J
DJ
Chun
Felix K-H
FK
Briganti
Alberto
A
Guille
Francois
F
Perrotte
Paul
P
Lobel
Bernard
B
Ficarra
Vincenzo
V
Artibani
Walter
W
Cindolo
Luca
L
Tostain
Jacques
J
Abbou
Clement-Claude
CC
Chopin
Dominique
D
De La Taille
Alexandre
A
Patard
Jean-Jacques
JJ
D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology*; D015331:Cohort Studies; D006801:Humans; D007668:Kidney / Q000473:pathology; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008954:Models, Biological; D009362:Neoplasm Metastasis / Q000175:diagnosis; D009367:Neoplasm Staging / Q000379:methods*; D009929:Organ Size; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D016019:Survival Analysis