Objective: To evaluate precystectomy prediction of pT and pN stages at cystectomy.
Methods: Multivariate logistic regression analyses modelled variables of 726 evaluable patients treated with radical cystectomy and bilateral pelvic lymphadenectomy. The first set of models predicted pT(3-4) stage at cystectomy, and the second set predicted pN(1-3) stages at cystectomy. Transurethral resection (TUR) predictors consisted of 2002 T stage, 1973 WHO tumour grade, presence of carcinoma in situ, age, gender, and delivery of neo-adjuvant chemotherapy. The area under the ROC curve quantified nomogram accuracy. Two hundred bootstrap resamples were used to reduce overfit bias.
Results: At TUR, 11% of patients were staged as pT(3-4) versus 42% at cystectomy. Lymph node metastases were found in 24% of patients at cystectomy (pN(1-3)). The multivariate pT(3-4) nomogram was 75.7% accurate versus 71.4% for TUR T stage. The multivariate pN(1-3) nomogram was 63.1% accurate versus 61.0% for TUR T stage.
Conclusion: Multivariate nomograms are not perfect, but they do predict more accurately than TUR T stage alone.