PSMA Expression Predicts Early Biochemical Response in Patients with Metastatic Castration-Resistant Prostate Cancer under 177Lu-PSMA-617 Radioligand Therapy.
Cancers (Basel)
; 13(12)2021 Jun 11.
Article
en En
| MEDLINE
| ID: mdl-34208246
ABSTRACT
177Lu-Prostate-specific membrane antigen (PSMA)-radioligand therapy (RLT) is a promising treatment option in patients with metastatic castration-resistant prostate cancer (mCRPC). We aimed to determine the predictive value of pretherapeutic PSMA-ligand positron emission tomography (PET) and established clinical parameters for early biochemical response after two cycles of RLT. In total, 71 mCRPC patients who had undergone PET/computed tomography (CT) with 68Ga-PSMA-11 prior to two cycles of 177Lu-PSMA-617 RLT were included. Malignant lesions on pretherapeutic PET/CTs were manually segmented and average maximum PSMA expression (maximum standardized uptake values, SUVmax), whole-body PSMA-tumor volume (TV), and whole-body total lesion (TL)-PSMA were calculated. We then tested the predictive performance of these parameters for early biochemical response (defined as prostate-sepcific antigen (PSA) decrease of ≥50% according to PCWG2) after two cycles of RLT, relative to established clinical parameters. Early PSA response was observed in 34/71 patients. PSA change after two cycles of RLT correlated with pretherapeutic SUVmax (r = -0.49; p < 0.001), but not with PSMA-TV (r = 0.02; p = 0.89) or TL-PSMA (r = -0.15; p = 0.22). A cut-off of 19.8 for SUVmax and 75.5 years for age was defined by receiver operating characteristics and revealed a significant outcome difference for early biochemical response between patients with adversely low vs. high PSMA expression and low vs. high age (p < 0.001). Multivariate analysis identified SUVmax (HR, 7.94, p = 0.001) and age (HR, 8.05, p = 0.002) as independent predictors for PSA response early in the treatment course. Thus, high age and high PSMA expression in patients scheduled for RLT identify patients with early biochemical response. This study provides a rationale for further prospective studies exploring PET-guided treatment intensification in selected patients.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Cancers (Basel)
Año:
2021
Tipo del documento:
Article
País de afiliación:
Alemania