5-Alpha reductase inhibitors in active surveillance

Five-alpha reductase inhibitors in men undergoing active surveillance for prostate cancer: impact on treatment and reclassification after 6 years follow-up

OBJECTIVES

To evaluate the impact of 5-alpha reductase inhibitors (5-ARIs) on definitive treatment (DT) and pathological progression (PP) in patients on active surveillance (AS) for prostate cancer.

METHODS

We identified 361 consecutive patients, from an IRB-approved database, on AS for prostate cancer with minimum 2 years follow-up. Patients were grouped into two cohorts, those using 5-ARIs (5-ARI; n = 119) or not using 5-ARIs (no 5-ARI; n = 242). Primary and secondary endpoints were treatment-free survival (TFS) and PP-free survival (PPFS), which were evaluated by Kaplan-Meier analysis. Univariate and multivariable cox regression analysis were used to identify predictors for PP and DT. A p value < 0.05 was considered statistically significant.

RESULTS

Baseline characteristics and the prostate biopsy rate were similar between the two groups. Median (range) follow-up was 5.7 (2.0-17.2) years. Five-year and 10-year TFS was 92% and 59% for the 5-ARI group versus 80% and 51% for the no 5-ARI group (p = 0.005), respectively. Five-year and 10-year PPFS was 77% and 41% for the 5-ARI group versus 70% and 32% for the no 5-ARI group (p = 0.04), respectively. Independent predictors for treatment and PP were not taking 5-ARIs (p = 0.005; p = 0.02), entry PSA > 2.5 ng/mL (p = 0.03; p = 0.01) and Gleason pattern 4 on initial biopsy (p < 0.001; p < 0.001), respectively. The main limitation is the retrospective study design.

CONCLUSIONS

5-ARIs reduces reclassification and cross-over to treatment in men on active surveillance for prostate cancer. Further, taking 5-ARIs was an independent predictor for prostate cancer progression and definitive treatment.

Long-term use of 5-alpha-reductase inhibitors is safe and effective in men on active surveillance for prostate cancer

BACKGROUND

Although 5-alpha-reductase inhibitors (5ARIs) have been shown to benefit men with prostate cancer (PCa) on active surveillance (AS), their long-term safety remains controversial. Our objective is to describe the long-term association of 5ARI use with PCa progression in men on AS.

MATERIALS/SUBJECTS AND METHODS

The cohort of men with low-risk PCa was derived from a prospectively maintained AS database at the Princess Margaret (1995-2016). Pathologic, grade, and volume progression were the primary end points. Kaplan-Meier time-to-event analysis was performed and Cox proportional hazards regression was used to determine predictors of progression where 5ARI exposure was analyzed as a time-dependent variable. Patients who came off AS prior to any progression events were censored at that time.

RESULTS

The cohort included 288 men with median follow-up of 82 months (interquartile range: 37-120 months). Among non-5ARI users (n = 203); 114 men (56.2%) experienced pathologic progression compared with 24 men (28.2%) in the 5ARI group (n = 85), (p < 0.001). Grade and volume progression were higher in the non-5ARI group compared with the 5ARI group (n = 82; 40.4% vs. n = 19; 22.4% respectively, p = 0.003 for grade progression; n = 87; 43.1% and n = 15; 17.7%, respectively for volume progression p < 0.001). Lack of 5ARI use was independently positively associated with pathologic progression (HR: 2.65; CI: 1.65-4.24), grade progression (HR: 2.75; CI: 1.49-5.06), and volume progression (HR: 3.15; CI: 1.78-5.56). The frequency of progression to high-grade (Grade Group 4-5) tumors was not significantly different between the groups.

CONCLUSIONS

Use of 5ARIs diminished both grade and volume progression without an increased risk of developing Grade Groups 4-5 disease.

Glycogen synthase kinase-3: a potential preventive target for prostate cancer management

OBJECTIVES

Prostate cancers are the frequently diagnosed cancers in men, and patients with metastatic disease only have 28% chance for 5-year survival. Patients with low-risk tumors are subjected to active surveillance, whereas high-risk cases are actively treated. Unfortunately, there is no cure for patients with late-stage disease. Glycogen synthase kinase-3 (GSK-3, α and β) is a protein serine/threonine kinase and has diverse cellular functions and numerous substrates. We sought to summarize all the studies done with GSK-3 in prostate cancers and to provide a prospective direction for future work.

METHODS AND MATERIALS

A comprehensive search of the literature on the electronic databases PubMed was conducted for the subject terms of GSK-3 and prostate cancer. Gene mutation and expression information was extracted from Oncomine and COSMIC databases. Case reports were not included.

RESULTS

Accumulating evidence indicates that GSK-3α is mainly expressed in low-risk prostate cancers and is related to hormone-dependent androgen receptor (AR)-mediated gene expression, whereas GSK-3β is mainly expressed in high-risk prostate cancers and is related to hormone-independent AR-mediated gene expression. GSK-3 has been demonstrated as a positive regulator in AR transactivation and prostate cancer growth independent of the Wnt/β-catenin pathway. Different types of GSK-3inhibitors including lithium show promising results in suppressing tumor growth in different animal models of prostate cancer. Importantly, clinical use of lithium is associated with reduced cancer incidence in psychiatric patients.

CONCLUSIONS

Taken together, GSK-3 inhibition might be implicated in prostate cancer management as a preventive treatment.