Radioisotope Imaging and Therapy for Bone Metastasis in Men With Castration-Resistant Prostate Cancer
Ce dossier présente deux études concernant le cancer métastatique de la prostate résistant à la castration : l'une analysant l'association entre la détection par scintigraphie, réalisée après le premier ou le second traitement, de nouvelles lésions osseuses non confirmées par examens radiographiques et la survie des patients (1 672 patients ; âge médian : 70 ou 72 ans selon le groupe), l'autre évaluant, en fonction du type de rayons émis (alpha ou bêta), l'effet sur la survie globale de radioisotopes ciblant les métastases osseuses (2 081 patients)
The current issue of JAMA Oncology includes 2 studies focusing on the use of radioisotopes for the management of bone lesions in patients with metastatic castration-resistant prostate cancer (mCRPC). In the first study, Armstrong and colleagues report the association between new unconfirmed bone lesions detected on the first or second posttreatment bone scans and outcomes in patients with mCRPC undergoing treatment with enzalutamide who otherwise had stable or decreasing prostate-specific antigen levels or soft-tissue lesions. This retrospective analysis involved 1672 men with mCRPC from 2 randomized clinical placebo-controlled phase 3 studies that investigated enzalutamide in the docetaxel-naive (PREVAIL [A Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients With Progressive Metastatic Prostate Cancer; NCT01212991]) and postdocetaxel (AFFIRM [Safety and Efficacy Study of MDV3100 in Patients With Castration-Resistant Prostate Cancer Who Have Been Previously Treated With Docetaxel-based Chemotherapy; NCT00974311]) settings. Early pseudoprogression was defined as 1 or more new unconfirmed lesions detected on the first posttreatment bone scan in patients with disease otherwise responding to treatment at week 9 in PREVAIL and at week 13 in AFFIRM, and late pseudoprogression was defined as 1 or more new unconfirmed lesions detected on the second posttreatment bone scan in patients with disease otherwise responding to treatment at week 17 in PREVAIL and at week 25 in AFFIRM. Unconfirmed bone lesions were found in 27.5% of patients in the predocetaxel setting (PREVAIL) and 18.1% of patients in the postdocetaxel setting (AFFIRM). Patients with stable disease and disease responding to treatment with pseudoprogression in the predocetaxel group had similar overall survival (OS) as those with no new unconfirmed bone lesions, confirming pseudoprogression. However, the postdocetaxel group of patients with bone pseudoprogression had significantly worse OS (HR, 1.94; 95% CI, 1.10-3.44) compared with responding patients with no new unconfirmed bone lesions, suggesting true progression of disease.
JAMA Oncology , commentaire, 2018