ABSTRACT
OBJECTIVE: Determining the concentration of prestin in human blood, cerebrospinal fluid (CSF), and perilymph (PL), and evaluating its suitability as a clinical biomarker for sensori-neural hearing loss (SNHL). STUDY DESIGN: Human blood, CSF, and PL samples were intraoperatively collected from 42 patients with tumors of the internal auditory canal or with intracochlear tumors undergoing translabyrinthine or middle fossa tumor removal. Prestin concentration was measured using enzyme-linked immunosorbent assay and linear regression analyses were performed to investigate its associations with audiological as well as vestibular test results. SETTING: Tertiary referral center. RESULTS: The median prestin concentration in blood samples of the 42 study participants (26 women, mean ± standard deviation age, 52.7 ± 12.5 years) was 1.32 (interquartile range, IQR, 0.71-1.99) ng/mL. CSF prestin levels were significantly higher with 4.73 (IQR, 2.45-14.03) ng/mL (P = .005). With 84.74 (IQR, 38.95-122.00) ng/mL, PL prestin concentration was significantly higher compared to blood (P = .01) and CSF (P = .03) levels. Linear regression analyses showed significant associations of CSF prestin concentration with preoperative hearing levels (pure-tone average and word recognition; P = .008, R2 = 0.1894; P = .03, R2 = 0.1857), but no correlations with blood or PL levels. CONCLUSION AND RELEVANCE: This study's findings highlight the volatile nature of prestin levels and provide the first insights into this potential biomarker's concentrations in body fluids apart from blood. Future investigations should comprehensively assess human prestin levels with different etiologies of SNHL, prestin's natural homeostasis and systemic circulation, and its temporal dynamics after cochlear trauma. Finally, clinically approved detection kits for prestin are urgently required prior to considering a potential translational implementation of this diagnostic technique.
ABSTRACT
BACKGROUND: Patients with nonmetastatic prostate cancer (nmPCa) and high prostate-specific antigen (PSA) levels due to the high likelihood of metastasis pose a clinical dilemma regarding their optimal treatment and long-term outcomes after initial local therapy. We aimed to evaluate the oncologic outcomes of patients treated with radical prostatectomy (RP) or radiotherapy (RT) for nmPCa with high PSA levels. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER) database to identify patients diagnosed with nmPCa who received RP or RT from 2004 through 2015. We included nmPCa patients with high PSA levels categorized as ≥50 and ≥98 ng/mL, the highest level recorded in SEER. We used the Kaplan-Meier method and Cox proportional hazards to analyze cancer-specific (CSS) and overall survival (OS). RESULTS: We included 6177 patients with nmPCa and PSA ≥ 50 ng/mL at diagnosis; 1698 (27%) had PSA ≥ 98 ng/mL. Of these, 1658 (26.8%) underwent RP and 4519 (73.16%) patients received primary RT. Within a median of 113 months (interquartile range 74-150 months), the 5- and 10-year CSS estimates were 92.3% and 81.5% respectively; 10-year OS was 61%. In the PSA ≥ 98 ng/mL subgroup 5- and 10-year CSS estimates were 89.2% and 76%, respectively. In multivariable analyses for CSS, ISUP grade group (p < 0.001), N stage (p < 0.001), treatment with RP (hazard ratio [HR] = 0.60, 95% confidence interval [CI] 0.43-0.83, p < 0.001), and patient's age (p < 0.05) were associated with improved CSS. In the whole cohort of patients with PSA ≥ 50 ng/mL and RP subgroup, PSA failed to retain its independent prognostic value for CSS. CONCLUSIONS: Patients treated with local therapy for nmPCa with very high PSA at diagnosis have relatively good long-term oncological outcomes. Therefore, among well-selected patients with nmPCa, high PSA levels alone should not preclude the use of radical local therapy. Potential selection bias limits inferences about the relative effectiveness of specific local therapies in this setting.
