MP32-07 CHANGES IN THE CONDITIONAL NET SURVIVAL AND DYNAMIC PROGNOSTIC FACTORS IN PATIENTS WITH NEWLY DIAGNOSED METASTATIC PROSTATE CANCER
INTRODUCTION AND OBJECTIVE:
The treatment strategy for patients with de novo metastatic prostate cancer (mPCa) has changed in recent years. Thus, an accurate assessment of the prognosis is critical. Conditional net survival provides a more appropriate method for estimating survival from cancer. This study aimed to identify predictive factors associated with conditional net survival in patients with de novo mPCa, initially treated with androgen deprivation therapy (ADT).
The medical records of 605 consecutive patients with de novo mPCa who initially received ADT were retrospectively reviewed. The Pohar–Perme estimator was used to calculate the conditional net cancer-specific survival (CSS) and overall survival (OS) for up to five years after the diagnosis. Using multiple imputations, proportional hazard ratios for conditional CSS and OS were calculated using adjusted Cox regression models.
During the follow-up, 208 patients died, out of which 169 died of progressive prostate cancer. At baseline, the 5-year CSS and OS rates were 65.5% and 58.2%, respectively. The overall conditional 5-year net OS rate at baseline was 0.582, and the overall conditional 5-year net OS rates for patients who survived for 1, 2, 3, 4, and 5 years were 0.566 (−0.16), 0.615 (+3.3), 0.550 (−0.32), 0.702 (+1.2), and 0.811 (+2.29), respectively. The conditional 5-year net CSS and OS survival gradually increased for all the patients. In patients who were given a 5-year survivorship, the conditional 5-year net CSS and OS rates improved to 0.906 and 0.811, respectively. Only the extent of disease score (EOD)≥2 remained a prognostic factor for CSS and OS up to 5 years. With an increase in the survival time, other variables were no longer independent prognostic factors.
The conditional 5-year net CSS and OS in patients with de novo mPCa gradually increased; thus, the risk of mortality decreased with increased survival. The patient’s risk profile changed over time. EOD remained an independent prognostic factor for CSS and OS after the 5-year follow-up. Conditional net survival can affect clinical decision-making, thus providing intriguing information for cancer survivors.
Source of Funding: