Intermittent androgen deprivation in prostate cancer cases with biochemical progression after radical prostatectomy: Are we ready to treat?

Intermittent Versus Continuous Androgen Deprivation Therapy for Biochemical Progression After Primary Therapy in Hormone-Sensitive Nonmetastatic Prostate Cancer: Comparative Analysis in Terms of CRPC-M0 Progression

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.

Population-based Assessment of Intermittent Androgen Deprivation Therapy Utilization for Relapsed, Nonmetastatic, Hormone-sensitive Adenocarcinoma of the Prostate

OBJECTIVES

Androgen deprivation therapy (ADT) is the standard of care for men with nonmetastatic hormone-sensitive prostate cancer (nmHSPC) after treatment failure. Although intermittent ADT (iADT) is noninferior to continuous ADT for prostate cancer outcomes, with superior quality of life and cost-to-benefit ratio, little is known regarding its real-world utilization. The authors aimed to determine the utilization of iADT in a Canadian Provincial Cancer Program for relapsed nmHSPC and identified risk factors associated with the nonreceipt of iADT.

MATERIALS AND METHODS

This retrospective population-based cohort study used linked administrative databases to identify all patients with relapsed nmHSPC from 2012 to 2016 and quantified ADT prescription history. Patients were defined as iADT eligible if prostate-specific antigen (PSA) was <4 ng/mL and trending downwards on ≥2 sequential PSAs after ≥6 months of ADT. Univariable and multivariable logistic regression analyses were performed to determine factors associated with nonreceipt of iADT.

RESULTS

A total of 601 men with relapsed, nmHSPC were included with a median age at relapse of 73 (range, 46 to 96), pre-ADT PSA of 12.2 ng/mL, and a median pre-ADT PSA doubling time of 7.8 months. 80.9% of the cohort were eligible to receive iADT and 74.4% were treated with iADT. On multivariable analysis, patients originally treated with surgery (odds ratio [OR], 0.19; 95% confidence interval [CI], 0.08-0.46) or having a Gleason Score ≥8 (OR, 0.30; 95% CI, 0.12-0.78) had decreased odds of receipt of iADT. Patients with longer PSA doubling times were more likely to receive iADT (OR, 2.71; 95% CI, 1.17-6.31).

CONCLUSIONS

The utilization of iADT was relatively common for men in Manitoba during the study period, however, the uptake of iADT can be improved among identified subgroups.