A multivariate prognostic nomogram incorporating PSA kinetics in hormone-refractory metastatic prostate cancer (HRPC)
5058 Background: To develop a prognostic model and nomogram using baseline clinical variables to predict death among men with metastatic hormone-refractory prostate cancer (HRPC). Methods: TAX 327 was a clinical trial that randomized 1,006 men with metastatic HRPC to receive 3-weekly or weekly docetaxel or mitoxantrone, each with prednisone. Of these, 635 men had baseline data that included PSA kinetics, with 518 mortality events recorded as of November 2006. We developed a multivariate Cox model and nomogram to predict survival at two, three, and five years. Results: Ten independent prognostic factors were identified in multivariate analysis and include: 1) presence of liver metastases (HR 1.64, p=0.02), 2) number of metastatic sites (HR 1.58 if =2 sites, p=0.001), 3) clinically significant pain at baseline (HR 1.46, p<0.0001), 4) Karnofsky Performance Status (HR 1.42 if =70, p=0.01), 5) type of progression at baseline (HR 1.40 for measurable disease progression and 1.28 for bone scan progression, p=0.002 and 0.014 respectively), 6) pretreatment PSA doubling time (PSADT, HR 1.20 if <55 days, p=0.048), 7) baseline PSA (HR 1.17 per log rise, p<0.0001), 8) tumor grade (HR 1.18 for high grade, p=0.076), 9) alkaline phosphatase (HR 1.26 per log rise, p<0.0001), and 10) hemoglobin (HR 1.10 per unit decline, p=0.006). A PSADT <55 days (median value for this dataset) was associated with other adverse prognostic factors, but was independently associated with shortened overall survival. Men with a PSA less than the median of 114 ng/ml and longer PSADT (=55 days) had a median survival of 24.7 months, while those with higher PSA and shorter PSADT had a median survival of 13.8 months. A nomogram was developed based on this Cox multivariate model and validated internally using bootstrap methods, with a concordance index of 0.69. Conclusions: This multivariate model identified several prognostic factors in men with metastatic HRPC including PSADT, and led to the successful development of a clinically applicable nomogram. External prospective validation may support the wider use of this prognostic baseline model for men with HRPC treated with chemotherapy. No significant financial relationships to disclose.