Enzalutamide as monotherapy for advanced prostate cancer: why not? / Enzalutamida como monoterapia para cáncer de próstata avanzado: ¿por qué no?

OBJECTIVES: Prostate cancer (PCa) is an androgen-dependent disease. In some cases, the tumor progresses despite castration levels of serum testosterone, turning into the lethal phenotype of castration-resistant prostate cancer (CRPC), still driven by androgens and requiring the androgen receptor as a driver and responsible for progression. Enzalutamide, an androgen receptor inhibitor, is indicated for the treatment of metastatic CRPC, asymptomatic or mildly symptomatic, after failure of androgen deprivation. In both clinical trials that led to its approval, Enzalutamide was administered with an LHRH analog, setting the "standard of care" for its use. In this article we evaluate the available evidence and theory on the use of Enzalutamide as monotherapy. METHODS: Androgen deprivation well-known adverse events, together with the fact that its clinical benefit is moderate and the evidence strength is weak, and the direct negative impact on the common chronic conditions affecting this age-group led to investigation of Enzalutamide without LHRH analogs. RESULTS: There are clinical trials on Enzalutamide monotherapy for hormone-sensitive prostate cancer with favourable outcomes, and there are also two ongoing studies in different advanced PCa scenarios, the PROSPER and EMBARK trials. It would be up to now a safe alternative, with less toxicity and lower costs. CONCLUSION: It is mandatory to validate these early results on the use on Enzalutamide monotherapy for advanced prostate cancer, hormone-sensitive or castration resistant, metastatic or not, but in the meantime, we wonder, why not?

Outcome of radical prostatectomy in patients meeting criteria for active surveillance.

OBJECTIVES: Advances in diagnosis of prostate cancer (PCa)have led to an increased detection of these tumors, some of them with low-risk of progression, with the consequent risk of overdiagnosis and overt treatment. In consequence, there is a tendency to offer alternatives to active therapy, like active surveillance (AS)however, some patients under AS need definitive therapy and after surgery it becomes evident that they are not "low-risk" patients. We retrospectively reviewed the data of patients who met criteria for low-risk tumors treated with radical prostatectomy. METHODS: We selected 21 out of 190 patients treated with radical prostatectomy from January 2004 to December 2008 who met Epstein's criteria for low-risk tumors. We analyzed the number of organ-confined tumors,Gleason undergrading and understaging by biopsy, surgical margins and postoperative PSA. RESULTS: Mean age was 58.6 years; mean PSA was 6.6 ng/ml, predominant Gleason score was 6 (3+3), 76%were unilateral tumors and 90%were organ-confined, 10% had extracapsular extension, none had involvement of the seminal % vesicles, 15% of the patients had Gleason score >6 and surgical margins were positive in 30% of the specimens. Eighty five percent had their first postoperative PSA <0.10 ng/ml and 75% remain free of biochemical recurrence. According to the Johns Hopkins criteria for "incurable tumors ", our cohort had 28%. CONCLUSION: Patients with low-risk prostate cancer include cases that may have greater risk than estimated. In our series, we had 10% extracapsular disease, 15% understaging for Gleason score and 25% biochemical recurrence, which demonstrates that current criteria do not warrant good oncological results. Active surveillance offers good quality of life and acceptable oncological results, it can be proposed until definitive therapy, without seriously endangering the patient. Anyway, as a therapeutic tool, it still requires improvements. Technical advances are awaited so as to properly assess each patient's risk and to define the best therapeutic option for every case.