Nomogram Predictive of Cancer Specific Survival in Patients Undergoing Partial or Total Amputation for Squamous Cell Carcinoma of the Penis

Abstract

We created the first nomograms to predict cancer specific survival probabilities of patients with squamous cell carcinoma of the penis, clustering prognostic information from the most commonly used clinical and pathological variables. We retrospectively collected clinical and pathological data from 175 patients who had undergone surgery for squamous cell carcinoma of the penis from 1980 to 2002 at 11 urological centers in northeastern Italy. A logistic regression model was used to construct the nomogram. At a median followup of 24 months, 101 patients (57.7%) were alive and disease-free while 74 (42.3%) died of penile cancer. According to multivariate analyses, 2 models predictive of cancer specific survival probability were generated. The first model was based on the pathological findings of the primary tumor after penectomy and on the clinical stage of groin lymph nodes, while the second model included the pathological data of the primary tumor and groin lymph nodes. The concordance index was 0.728 for the first model and 0.747 for the second. Calibration appeared to be good in both models. In this article we propose 2 models to predict the 5-year cancer specific survival probabilities of patients with squamous cell carcinoma of the penis. Both models showed good discriminating power and calibration in predicting patient 5-year cancer specific survival. These nomograms could improve the quality of prognostic data provided to patients and support physicians in planning treatment.