Understanding of the molecular mechanisms of prostate cancer has led to development of therapeutic strategies targeting androgen receptor (AR). These androgen-receptor signaling inhibitors (ARSI) include androgen synthesis inhibitor-abiraterone and androgen receptor antagonists-enzalutamide, apalutamide, and darolutamide. Although these medications provide significant improvement in survival among men with prostate cancer, drug resistance develops in nearly all patients with time. This could be through androgen-dependent or androgen-independent mechanisms. Even weaker signals and non-canonical steroid ligands can activate AR in the presence of truncated AR-splice variants, AR overexpression, or activating mutations in AR. AR splice variant, AR-V7 is the most studied among these and is not targeted by available ARSIs. Non-androgen receptor dependent resistance mechanisms are mediated by activation of an alternative signaling pathway when AR is inhibited. DNA repair pathway, PI3K/AKT/mTOR pathway, BRAF-MAPK and Wnt signaling pathway and activation by glucocorticoid receptors can restore downstream signaling in prostate cancer by alternative proteins. Multiple clinical trials are underway exploring therapeutic strategies to overcome these resistance mechanisms.

Importance: A high incidence of fall and fracture in a subset of patients treated with androgen receptor inhibitors (ARIs) has been reported, although the relative risk (RR) of fall and fracture for patients who receive ARI treatment is unknown.Objective: To evaluate whether treatment with ARIs is associated with an elevated relative risk for fall and fracture in patients with prostate cancer.Data Sources: Cochrane, Scopus, and MedlinePlus databases were searched from inception through August 2019.Study Selection: Randomized clinical trials comparing patients with prostate cancer treated with any ARI or placebo were included.Data Extraction and Synthesis: Two independent reviewers used a standardized data extraction and quality assessment form. A mixed effects model was used to estimate the effects of ARI on relative risk, with included studies treated as random effects and study groups treated as fixed effects in the pooled analysis. Sample size for each study was used to weight the mixed model. Statistical analysis was performed from August to October 2019.Main Outcomes and Measures: The primary outcome was RR of fall and fractures for patients receiving ARI treatment.Results: Eleven studies met this study’s inclusion criteria. The total population was 11 382 men (median [range] age: 72 [43-97] years), with 6536 in the ARI group and 4846 in the control group. Participants in the ARI group could have received enzalutamide, apalutamide, or darolutamide in combination with androgen deprivation therapy or other enzalutamide combinations; patients in the control group could have received placebo, bicalutamide, or abiraterone. The reported incidence of fall was 525 falls (8%) in the ARI group and 221 falls (5%) in the control group. The incidence of fracture was 242 fractures (4%) in the ARI group and 107 fractures (2%) in the control group. Use of an ARI was associated with an increased risk of falls and fractures: all-grade falls (RR, 1.8; 95% CI, 1.42-2.24; P < .001); grade 3 or greater fall (RR, 1.6; 95% CI, 1.27-2.08; P < .001); all-grade fracture (RR, 1.59; 95% CI, 1.35-1.89; P < .001), and likely grade 3 or greater fracture (RR, 1.71; 95% CI, 1.12-2.63; P = .01).Conclusions and Relevance: Use of ARI was associated with an increase in falls and fractures in patients with prostate cancer as assessed by a retrospective systematic review and meta-analysis. Further studies are warranted to identify and understand potential mechanisms and develop strategies to decrease falls and fractures associated with ARI use.

Background: Adjuvant treatment has always been a cornerstone in the therapeutic approach of many cancers, considering its role in reducing the risk of relapse and, in some cases, increasing overall survival. Adjuvant immune checkpoint inhibitors have been tested in different malignancies. Methods: We performed a meta-analysis aimed to explore the impact of adjuvant PD-1 and PD-L1 inhibitors on relapse-free survival (RFS) in cancer patients enrolled in randomized controlled clinical trials. We retrieved all phase III trials published from 15 June 2008 to 15 May 2022, evaluating PD-1/PD-L1 inhibitors monotherapy as an adjuvant treatment by searching on EMBASE, Cochrane Library, and PubMed/ Medline, and international oncological meetings’ abstracts. The outcome of interest was RFS. We also performed subgroup analyses focused on age and gender. Results: Overall, 8 studies, involving more than 6000 patients, were included in the analysis. The pooled results highlighted that the use of adjuvant PD-1/PD-L1 inhibitors may reduce the risk of relapse compared to control treatments (hazard ratio, 0.72; 95% confidence intervals, 0.67–0.78). In addition, the subgroup analyses observed that this benefit was consistent in different patient populations, including male, female, younger, and older patients. Conclusions: Adjuvant anti-PD-1/PD-L1 treatment is associated with an increased RFS in the overall population and in subgroups divided according to age and gender.

Understanding of the molecular mechanisms of prostate cancer has led to development of therapeutic strategies targeting androgen receptor (AR). These androgen-receptor signaling inhibitors (ARSI) include androgen synthesis inhibitor- abiraterone and androgen receptor antagonists- enzalutamide, apalutamide, and darolutamide. Although these medications provide significant improvement in survival among men with prostate cancer, drug resistance develops in nearly all patients with time. This could be through androgen-dependent or androgen-independent mechanisms. Even weaker signals and non-canonical steroid ligands can activate AR in the presence of truncated AR-splice variants, AR overexpression, or activating mutations in AR. AR splice variant, AR-V7 is the most studied among these and is not targeted by available ARSIs. Non-androgen receptor dependent resistance mechanisms are mediated by activation of an alternative signaling pathway when AR is inhibited. DNA repair pathway, PI3K/AKT/mTOR pathway, BRAF-MAPK and Wnt signaling pathway and activation by glucocorticoid receptors can restore downstream signaling in prostate cancer by alternative proteins. Multiple clinical trials are underway exploring therapeutic strategies to overcome these resistance mechanisms.