A large number of novel therapeutics is currently undergoing clinical evaluation for the treatment of prostate cancer, and small molecule signal transduction inhibitors are a promising class of agents. These inhibitors have recently become a standard therapy in renal cell carcinoma and offer significant promise in prostate cancer. Through an understanding of the key pathways involved in prostate cancer progression, a rational drug design can be aimed at the molecules critical to cellular signaling. This may enable administration of selective therapies based on the expression of molecular targets, more appropriately individualizing treatment for prostate cancer patients. One pathway with a prominent role in prostate cancer is the PI3K/Akt/mTOR pathway. Current estimates suggest that PI3K/Akt/mTOR signaling is upregulated in 30-50% of prostate cancers, often through loss of PTEN. Molecular changes in the PI3K/Akt/mTOR signaling pathway have been demonstrated to differentiate benign from malignant prostatic epithelium and are associated with increasing tumor stage, grade, and risk of biochemical recurrence. Multiple inhibitors of this pathway have been developed and are being assessed in the laboratory and in clinical trials, with much attention focusing on mTOR inhibition. Current clinical trials in prostate cancer are assessing efficacy of mTOR inhibitors in combination with multiple targeted or traditional chemotherapies, including bevacizumab, gefitinib, and docetaxel. Completion of these trials will provide substantial information regarding the importance of this pathway in prostate cancer and the clinical implications of its targeted inhibition. In this article we review the data surrounding PI3K/Akt/mTOR inhibition in prostate cancer and their clinical implications.
BACKGROUND. A number of minimally invasive technologies exist for the treatment of prostate cancer (CaP), each with their associated morbidities. We sought to test the efficacy of low dose alternating electric current (LDAEC) to inhibit CaP growth in a preclinical setting and determine its effect on normal tissue. METHODS. In the first study, two power settings, 15 or 25mA of current, and two treatment times, 15 or 60min, were evaluated in C4-2B CaP xenografts. In the second study, power was regulated to maintain an intra-tumoral temperature of ! 458C in C4-2B and LuCaP 35 tumors. In both studies, tumor volume, serum PSA levels, survival and histology were analyzed. In a third study, LDAEC was applied to mice hamstrings with evaluation of gait and histology. RESULTS. The most effective tumor volume reduction in thefirst study was seen with tumors treated with 25mA for 15min (62 9.4% decrease, P# 0.001). Longer treatment time did not enhance treatment effect. Using 458C to govern delivery of LDAEC resulted in a near 100% reductionintumorvolumein8/10micewithC4-2Btumors(P<0.001)withsimilarinhibitionof LuCaP 35 tumors (P# 0.01). This treatment, although resulting in skeletal muscle necrosis, did not affect nerves, smooth muscle and blood vessels. CONCLUSION. LDAEC demonstrates efficacy against C4-2B and LuCaP 35 CaP xenografts whilecausingnoharmtonervesandbloodvessels.Theseresultswarrantfurtherinvestigations into the use of LDAEC as a treatment for CaP. Prostate # 2009 Wiley-Liss, Inc.
Study Design. Observational epidemiological study Objective. This study’s primary objective was to examine the risk of recall for novel spine devices over time. Secondarily, we sought to analyze interbody fusion and vertebral body replacement (VBR) devices (corpectomy cages) as a risk factor for recall. Summary of Background Data. The recall risk of a novel spine device over time has not been reported. Additionally, FDA regulations were lowered for interbody fusion devices to enter the market in 2007. As well, VBR implants were recently approved by the FDA for use in the cervical spine in 2015. Methods. Spine devices cleared between January 1, 2008 and December 31, 2018 were identified from the FDA’s 510(k) database. All recall data was collected from the database in January of 2021 to provide a 2-year minimum follow-up for a recall to occur. Product labels were used to classify interbody fusion and VBR devices. Cumulative incidence function was conducted to compare the overall risk of recall for FDA cleared spine devices, and the hazard ratio determined for VBR and all other devices vs interbody implants during the study period. Results. 2,384 spine devices were cleared via 510(k) in the study period. The hazard of recall at 5 years was 5.3% (95% CI: 4.4%-6.2%) and 6.5% (95% CI: 5.4-7.7%) at 10 years. No significant difference in recall risk was identified for interbody fusion and VBR devices. Conclusion. The risk of recall at 5 and 10 years of a novel spine device is about half the 12% rate reported for orthopedic devices in general. Despite lowered FDA regulations for interbody fusion devices and recent approval for VBR device use in the cervical spine, no increased risk of recall was detected. Further research is necessary to explain the reason for the lower risk of recall with spine devices Level of Evidence. V
Introduction Vertebral endplates, innervated by the basivertebral nerve (BVN), are a source of chronic low back pain correlated with Modic changes. A randomized trial comparing BVN ablation to standard care (SC) recently reported results of an interim analysis. Here, we report the results of the full randomized trial, including the 3-month and 6-month between-arm comparisons, 12-month treatment arm results, and 6-month outcomes of BVN ablation in the former SC arm. Methods Prospective, open label, 1:1 randomized controlled trial of BVN ablation versus SC in 23 US sites with follow-up at 6 weeks, 3, 6, 9, and 12 months. SC patients were re-baselined and followed up for 6 months post BVN ablation. The primary endpoint was the between-arm comparison of mean Oswestry Disability Index (ODI) change from baseline. Secondary endpoints were Visual Analog Scale (VAS), Short Form (SF-36), EuroQual Group 5 Dimension 5-Level Quality of Life (EQ-5D-5L), responder rates, and rates of continued opioid use. Results 140 were randomized. Results from BVN ablation (n=66) were superior to SC (n=74) at 3 months for the primary endpoint (mean ODI reduction, difference between arms of −20.3 (CI −25.9 to −14.7 points; p<0.001)), VAS pain improvement (difference of −2.5 cm between arms (CI −3.37 to −1.64, p<0.001)) and quality of life outcomes. At 12 months, basivertebral ablation demonstrated a 25.7±18.5 point reduction in mean ODI (p<0.001), and a 3.8±2.7 cm VAS reduction (p<0.001) from baseline, with 64% demonstrating ≥50% reduction and 29% pain free. Similarly, the former SC patients who elected BVN ablation (92%) demonstrated a 25.9±15.5 point mean ODI reduction (p<0.001) from baseline. The proportion of opioid use did not change in either group (p=0.56). Discussion/Conclusion BVN ablation demonstrates significant improvements in pain and function over SC, with treatment results sustained through 12 months in patients with chronic low back pain of vertebrogenic origin.
Treatments for advanced prostate cancer (CaP) typically involve androgen deprivation therapy. However, most patients eventually develop castration-resistant CaP (CRPC) for which highly effective therapies are limited. We explored the efficacy of a novel agent, HE3235, in inhibiting growth of CRPC in preclinical models. Castrated male mice were implanted subcutaneously with LuCaP35V CaP xenografts in the presence and absence of 5′-androstenediol (AED) and treated with HE3235. To investigate the effect of HE3235 on CaP tumor in the bone, castrated mice were injected intratibially with C4-2B CaP cells and treated with HE3235. Serum prostate-specific antigen (PSA) levels, tumor volume, immunohistochemistry, gene expression, and levels of intratumoral androgens were analyzed. HE3235 significantly prolonged the tumor doubling time of LuCaP35V, decreased androgen receptor expression, and lowered levels of intratumoral testosterone by ∼89% and dihydrotestosterone by ∼63% in both the presence and the absence of AED. HE3235 inhibited tumor growth in the bone environment. Weights of tumored tibiae of HE3235-treated animals were lower than those of control (P = .031), and normalized PSA levels were also significantly decreased at the end of study by HE3235 treatment (P = .0076). HE3235 inhibits the growth of subcutaneous CRPC as well as CRPC in the bone environment. Our data show that HE3235 exhibits a wide range of effects, including alteration of androgen receptor signaling and reductions in levels of intratumoral androgens. Our results support ongoing clinical investigations into the effectiveness of HE3235 in the setting of CRPC and warrants further studies into the mechanisms behind the effects of HE3235.
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