RESUMEN
Biochemical recurrence (BCR) after primary treatments for prostate cancer (PC) is an extremely heterogeneous phase and at least a stratification into low- and high-risk cases for early progression in metastatic disease is necessary. At present, PSA-DT represents the best parameter to define low- and high-risk BCR PC, but real precision medicine is strongly suggested to define tailored management for patients with BCR. Before defining management, it is necessary to exclude the presence of low-volume metastasis associated with PSA progression using new-generation imaging, preferably with PSMA PET/CT. Low-risk BCR cases should be actively observed without early systemic therapies. Early treatment of low-risk BCR with continuous androgen deprivation therapy (ADT) can produce disadvantages such as the development of castration resistance before the appearance of metastases (non-metastatic castration-resistant PC). Patients with high-risk BCR benefit from early systemic therapy. Even with overall survival (OS) as the primary treatment endpoint, metastasis-free survival (MFS) should be used as a surrogate endpoint in clinical trials, especially in long survival stages of the disease. The EMBARK study has greatly influenced the management of high-risk BCR, by introducing the concept of anticipation and intensification through the use of androgen receptor signaling inhibitors (ARSIs) and ADT combination therapy. In high-risk (PSA-DT ≤ 9 months) BCR cases, the combination of enzalutamide with leuprolide significantly improves MFS when compared to leuprolide alone, maintaining an unchanged quality of life in the asymptomatic phase of the disease. The possibility of using ARSIs alone in this early disease setting is suggested by the EMBARK study (arm with enzalutamide alone) with less evidence than with the intensification of the combination therapy. Continued use versus discontinuation of enzalutamide plus leuprolide intensified therapy upon reaching undetectable PSA levels needs to be better defined with further analysis. Real-world analysis must verify the significant results obtained in the context of a phase 3 study.
RESUMEN
INTRODUCTION: To analyze whether the use of an intermittent (IAD) versus continuous (CAD) androgen deprivation therapy for the treatment of biochemical progression after primary treatments in prostate cancer can influence the development of nonmetastatic castration resistant prostate cancer (CRPC-M0). PATIENTS: 170 male patients with an histologically confirmed diagnosis of PC, presenting a biochemical progression after primary treatments (82 after radical prostatectomy and 88 after external radiation therapy), nonmetastatic at imaging were considered for continuous (85 cases) or intermittent (85 cases) administration of androgen deprivation therapy. METHODS: we retrospectively collect all data regarding histological diagnosis, primary treatment, imaging for M0-M1 staging, PSA at progression, time to biochemical progression from primary therapy, ADT used, IAD cycles, so to compare in 2 groups (IAD vs. CAD) time for progression from the beginning of ADT treatment and type of progression in terms of CRPC-M0 versus CRPC-M1 cases. RESULTS: no significant (P= .4955) difference in the whole CRPC progression was found between IAD (25.8%) and CAD (30.5%) treatment at a mean of 32.7 ± 7.02 months and 35.6 ± 13.1 months respectively (P= .0738). Mean PSA at CRPC development was significantly higher in the IAD group (5.16 ± 0.68 ng/mL) than in the CAD group (3.1 ± 0.7 ng/mL) (P < .001). In all cases, imaging to detect M status at CRPC development was PET TC scan. At univariate analysis CAD administration significantly increases the RR for CRPC-M0 progression (RR 3.48; 95%CI 1.66-7.29; P = .01) when compared to the IAD administration, and this effect at multivariate analysis remained significant and independent to the other variables (RR 2.34, 95%CI 1.52-5.33; P = .03). CONCLUSIONS: in our population with biochemical progression after primary treatment for PC, the intermittent administration of ADT significantly reduces the risk to develop CRPC-M0 disease when compared to a continuous administration of ADT, whereas no difference between the 2 strategies in terms of CRPC-M1 progression exists.