Abstract
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Objectives To compare the application of 3 response criteria in men with metastatic castrate-sensitive prostrate cancer (mCSPC) undergoing hormonal treatment and in relationship to time to hormonal treatment failure (THTF).
Methods 61 men with CSPC underwent FDG PET/CT at baseline and 4 mo after hormonal treatment. Treatment response was compared to baseline using RECIST 1.0, PERCIST 1.0 and PCWG2. Associations between patients’ response status and Time to Hormonal Treatment Failure (THTF) were examined. THTF was the duration in time between date of baseline PET/CT imaging and date of change to chemotherapy or date of death, with patients who were alive and who had not switched to chemotherapy censored at the last follow-up date. Response was compared using waterfall plots and THTF for patients with different response status (CR/PR, SD, and PD) was compared with log rank tests.
Results Not all 61 patients were evaluable by all 3 response-criteria; the number of evaluable patients was 59 for PCWG2, 33 for RECIST 1.0 and 40 for PERCIST 1.0. The kappa statistics were as follows: 0.64 for RECIST 1.0 vs. PCWG2, 0.45 for PERCIST 1.0 vs. PCWG2, and 0.47 for PERCIST 1.0 vs. RECIST 1.0. The probability of free from THTF at 24 mo was 49%+/- 6% (n=61) with median THTF of 22.9 mo (95% CI: 11.5-43.9 mo). For all 3 response-criteria, the progressors (PD for PCWG2 and RECIST 1.0 and PMD for PERCIST 1.0) had significantly poorer prognosis with respect to THTF.
Conclusions RECIST 1.0 was associated with least number of evaluable patients and most concordant with PCWG2. All 3 response-criteria progressors had significantly higher risk of THTF when compared to nonprogressors.
Research Support NIH-NCI grants R01-CA111613 (PI: H. Jadvar) and P30-CA014089.