ABSTRACT
Primary cell cultures are essential tools for elucidating the physiopathological mechanisms of the cardiovascular system. Therefore, a primary culture growth protocol of cardiovascular smooth muscle cells (VSMCs) obtained from human abdominal aortas was standardized. Ten abdominal aorta samples were obtained from patients diagnosed with brain death who were organ and tissue donors with family consent. After surgical ablation to capture the aorta, the aortic tissue was removed, immersed in a Custodiol® solution, and kept between 2 and 8 °C. In the laboratory, in a sterile environment, the tissue was fragmented and incubated in culture plates containing an enriched culture medium (DMEM/G/10% fetal bovine serum, L-glutamine, antibiotics and antifungals) and kept in an oven at 37 °C and 5% CO2. The aorta was removed after 24 h of incubation, and the culture medium was changed every six days for twenty days. Cell growth was confirmed through morphological analysis using an inverted optical microscope (Nikon®) and immunofluorescence for smooth muscle alpha-actin and nuclei. The development of the VSMCs was observed, and from the twelfth day, differentiation, long cytoplasmic projections, and adjacent cell connections occurred. On the twentieth day, the morphology of the VSMCs was confirmed by actin fiber immunofluorescence, which is a typical characteristic of VSMCs. The standardization allowed VSMC growth and the replicability of the in vitro test, providing a protocol that mimics natural physiological environments for a better understanding of the cardiovascular system. Its use is intended for investigation, tissue bioengineering, and pharmacological treatments.
Subject(s)
Aorta, Abdominal , Vascular Diseases , Humans , Brain Death/metabolism , Brain Death/pathology , Muscle, Smooth, Vascular/metabolism , Vascular Diseases/metabolism , Vascular Diseases/pathology , Models, Theoretical , Myocytes, Smooth Muscle , Brain , Cells, CulturedABSTRACT
BACKGROUND: Robotic-assisted radical cystectomy (RARC) with intracorporeal urinary diversion (ICUD) is associated with significant morbidity and mortality. We present an alternative technique that preserves the complete mesenteric vascularization during the isolation of the intestinal segment used in ICUD, including distal vessels. This approach aims to minimize the risk of ischemia in both the ileal anastomosis and the isolated loop at the diversion site. METHODS: This cohort study included 31 patients, both male and female, who underwent RARC with ICUD from February 2018 to November 2023, performed by a single surgeon. Intraoperative and postoperative complications data were retrieved for analysis, employing our proposed mesentery-sparing technique in all cases. The primary endpoint was the incidence of intraoperative and postoperative complications directly attributable to the mesentery-sparing approach in ICUD. Secondary endpoints included other postoperative variables not directly related to mesentery preservation, such as the incidence of postoperative ileus requiring parenteral nutrition and the duration of hospitalization. RESULTS: None of the patients experienced intraoperative or postoperative complications directly related to mesentery-sparing, such as intestinal fistulae or internal hernias. The median duration of hospitalization was 6 days, and postoperative ileus necessitating total parenteral nutrition occurred in 19% of the patients. Minor complications (Clavien-Dindo grades I-II) accounted for 27.6% of the cases and major complications (grades III-V) accounted for 20.6%. CONCLUSION: The mesentery-sparing technique outlined herein offers an alternative method for preserving the vascularization of intestinal segments and reducing the risk of intestinal complications in ICUD during RARC.
Subject(s)
Cystectomy , Mesentery , Postoperative Complications , Robotic Surgical Procedures , Urinary Diversion , Humans , Cystectomy/methods , Female , Male , Robotic Surgical Procedures/methods , Urinary Diversion/methods , Middle Aged , Aged , Postoperative Complications/prevention & control , Mesentery/surgery , Urinary Bladder Neoplasms/surgery , Organ Sparing Treatments/methods , Treatment Outcome , Intraoperative Complications/prevention & control , Retrospective Studies , Reproducibility of Results , Cohort StudiesABSTRACT
A multiplex 6-gene copy number classifier was used to distinguish between low- or intermediate-risk prostate cancer patients. The study analysed a cohort of 448 patients and previously published datasets from radical prostatectomies. The classifier performs better than conventional stratification methods, is low cost, and can be performed easily in clinical laboratories.
Subject(s)
Precision Medicine , Prostatectomy , Prostatic Neoplasms , Humans , Male , Prostatic Neoplasms/genetics , Prostatic Neoplasms/surgery , Gene Dosage , DNA Copy Number Variations , Risk Assessment , Cohort Studies , Datasets as TopicABSTRACT
BACKGROUND: Although penile cancer (PC) is uncommon in developed countries, it is widespread in developing countries. The state of Maranhão (Northeast, Brazil) has the highest global incidence recorded for PC, and, despite its socioeconomic vulnerability, it has been attributed to human papillomavirus (HPV) infection. This study aimed to determine the histopathological features, the prevalence of HPV infection, and the immunohistochemical profile of PC in Maranhão. METHODS: A retrospective cohort of 200 PC cases were evaluated. HPV detection was performed using nested-PCR followed by direct sequencing for genotyping. Immunohistochemistry (IHC) was performed using monoclonal antibodies anti-p16INK4a, p53, and ki-67. RESULTS: Our data revealed a delay of 17 months in diagnosis, a high rate of penile amputation (96.5%), and HPV infection (80.5%) in patients from Maranhão (Molecular detection). We demonstrated the high rate of HPV in PC also by histopathological and IHC analysis. Most patients presented koilocytosis (75.5%), which was associated with those reporting more than 10 different sexual partners during their lifetime (p = 0.001). IHC revealed frequent p16INK4a overexpression (26.0%) associated with basaloid (p < 0.001) and high-grade tumors (p = 0.008). Interestingly, p16 appears not to be a better prognostic factor in our disease-free survival analysis, as previously reported. We also demonstrated high ki-67 and p53 expression in a subset of cases, which was related to worse prognostic factors such as high-grade tumors, angiolymphatic and perineural invasion, and lymph node metastasis. We found a significant impact of high ki-67 (p = 0.002, log-rank) and p53 (p = 0.032, log-rank) expression on decreasing patients' survival, as well as grade, pT, stage, pattern, and depth of invasion (p < 0.05, log-rank). CONCLUSIONS: Our data reaffirmed the high incidence of HPV infection in PC cases from Maranhão and offer new insights into potential factors that may contribute to the high PC incidence in the region. We highlighted the possible association of HPV with worse clinical prognosis factors, differently from what was observed in other regions. Furthermore, our IHC analysis reinforces p16, ki-67, and p53 expression as important diagnosis and/or prognosis biomarkers, potentially used in the clinical setting in emerging countries such as Brazil.
Subject(s)
Papillomavirus Infections , Penile Neoplasms , Antibodies, Monoclonal/metabolism , Biomarkers, Tumor/analysis , Biomarkers, Tumor/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Humans , Incidence , Ki-67 Antigen/genetics , Ki-67 Antigen/metabolism , Male , Papillomaviridae/metabolism , Papillomavirus Infections/complications , Papillomavirus Infections/epidemiology , Penile Neoplasms/epidemiology , Penile Neoplasms/pathology , Prognosis , Retrospective Studies , Tumor Suppressor Protein p53/geneticsABSTRACT
Bladder cancer (BCa) is one of the most common cancers worldwide and is also considered to be one of the most relapsing and aggressive neoplasms. About 30% of patients will present with muscle invasive disease, which is associated with a higher risk for metastatic disease. The aim of this article is to review the state of art imaging in Radiology, while providing a complete guide to urologists, with case examples, for the rationale of the development of the Vesical Imaging Reporting and Data System (VI-RADS), a scoring system emphasizing a standardized approach to multiparametric Magnetic Resonance Imaging (mpMRI) acquisition, interpretation, and reporting for BCa. Also, we examine relevant external validation studies and the consolidated literature of mpMRI for bladder cancer. In addition, this article discusses some of the potential clinical implications of this scoring system for disease management and follow-up.
Subject(s)
Multiparametric Magnetic Resonance Imaging , Urinary Bladder Neoplasms , Humans , Magnetic Resonance Imaging/methods , Neoplasm Recurrence, Local/pathology , Urinary Bladder/pathology , Urinary Bladder Neoplasms/diagnostic imaging , Urinary Bladder Neoplasms/pathology , UrologistsABSTRACT
BACKGROUND: Non-metastatic castration resistant prostate cancer (M0 CRPC) has seen important developments in drugs and diagnostic tools in the last two years. New hormonal agents have demonstrated improvement in metastasis free survival in M0 CRPC patients and have been approved by regulatory agencies in Brazil. Additionally, newer and more sensitive imaging tools are able to detect metastasis earlier than before, which will impact the percentage of patients staged as M0 CRPC. Based on the available international guidelines, a group of Brazilian urology and medical oncology experts developed and completed a survey on the diagnosis and treatment of M0 CRPC in Brazil. These results are reviewed and summarized and associated recommendations are provided. OBJECTIVE: To present survey results on management of M0 CRPC in Brazil. DESIGN, SETTING, AND PARTICIPANTS: A panel of six Brazilian prostate cancer experts determined 64 questions concerning the main areas of interest: 1) staging tools, 2) treatments, 3) side effects of systemic treatment/s, and 4) osteoclast-targeted therapy. A larger panel of 28 Brazilian prostate cancer experts answered these questions in order to create country-specific recommendations discussed in this manuscript. Outcome measurements and statistical analysis: The panel voted publicly but anonymously on the predefined questions. These answers are the panelists' opinions, not a literature review or meta-analysis. Therapies not yet approved in Brazil were excluded from answer options. Each question had five to seven relevant answers including two non-answers. Results were tabulated in real time. CONCLUSIONS: The results and recommendations presented can be used by Brazilian physicians to support the management of M0 CRPC patients. Individual clinical decision making should be supported by available data, however, for Brazil, guidelines for diagnosis and management of M0 CRPC patients have not been developed. This document will serve as a point of reference when confronting this disease stage.
Subject(s)
Consensus , Physicians , Prostatic Neoplasms, Castration-Resistant , Brazil , Humans , Male , Patient Selection , Perception , Prostatic Neoplasms, Castration-Resistant/diagnosis , Prostatic Neoplasms, Castration-Resistant/drug therapy , Treatment OutcomeABSTRACT
Mutations in PTEN activate the phosphoinositide 3-kinase (PI3K) signalling network, leading to many of the characteristic phenotypic changes of cancer. However, the primary effects of this gene on oncogenesis through control of the PI3K-AKT-mammalian target of rapamycin (mTOR) pathway might not be the only avenue by which PTEN affects tumour progression. PTEN has been shown to regulate the antiviral interferon network and thus alter how cancer cells communicate with and are targeted by immune cells. An active, T cell-infiltrated microenvironment is critical for immunotherapy success, which is also influenced by mutations in DNA damage repair pathways and the overall mutational burden of the tumour. As PTEN has a role in the maintenance of genomic integrity, it is likely that a loss of PTEN affects the immune response at two different levels and might therefore be instrumental in mediating failed responses to immunotherapy. In this review, we summarise findings that demonstrate how the loss of PTEN function elicits specific changes in the immune response in several types of cancer. We also discuss ongoing clinical trials that illustrate the potential utility of PTEN as a predictive biomarker for immune checkpoint blockade therapies.
Subject(s)
Biomarkers, Tumor/genetics , Neoplasms/genetics , Neoplasms/immunology , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/immunology , Animals , Humans , Immunotherapy , MutationABSTRACT
PURPOSE: Prostate cancer screening in the elderly is controversial. The Brazilian government and the National Cancer Institute (INCA) do not recommend systematic screening. Our purpose was to assess prevalence and aggressiveness of prostate cancer in men aged 70 years and above, on the first Latin American database to date. MATERIALS AND METHODS: Cross-sectional study (n=17,571) from 231 municipalities, visited by Mobile Cancer Prevention Units of a prostate-specific antigen (PSA) based opportunistic screening program, between 2004 and 2007. The criteria for biopsy were: PSA>4.0ng/ml, or PSA 2.5-4.0ng/ml with free/total PSA ratio ≤15%, or suspicious digital rectal examination findings. The screened men were stratified in two age groups (45-69 years, and ≥70 years). These groups were compared regarding prostate cancer prevalence and aggressiveness criteria (PSA, Gleason score from biopsy and TNM staging). RESULTS: The prevalence of prostate cancer found was 3.7%. When compared to men aged 45-69 years, individuals aged 70 years and above presented cancer prevalence about three times higher (prevalence ratio 2.9, p<0.01), and greater likelihood to present PSA level above 10.0ng/ml at diagnosis (odds ratio 2.63, p<0.01). The group of elderly men also presented prevalence of histologically aggressive disease (Gleason 8-10) 3.6 times higher (p<0.01), and 5-fold greater prevalence of metastases (PR 4.95, p<0.05). CONCLUSIONS: Prostate cancer screening in men aged over 70 may be relevant in Brazil, considering the absence of systematic screening, higher prevalence and higher probability of high-risk disease found in this age range of the population studied.
Subject(s)
Mass Screening/methods , Prostatic Neoplasms/diagnosis , Prostatic Neoplasms/epidemiology , Age Factors , Aged , Aged, 80 and over , Biopsy , Brazil/epidemiology , Cross-Sectional Studies , Digital Rectal Examination , Early Detection of Cancer , Humans , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Prevalence , Prostate-Specific Antigen/blood , Prostatic Neoplasms/pathology , Risk Assessment , Risk FactorsABSTRACT
INTRODUCTION: Penile cancer (PC) occurs less frequently in Europe and in the United States than in South America and parts of Africa. Lymph node (LN) involvement is the most important prognostic factor, and inguinal LN (ILN) dissection can be curative; however, ILN dissection has high morbidity. A nomogram was previously developed based on clinicopathological features of PC to predict ILN metastases. Our objective was to conduct an external validation of the previously developed nomogram based on our population. MATERIALS AND METHODS: We included men with cN0 ILNs who underwent ILN dissection for penile carcinoma between 2000 and 2014. We performed external validation of the nomogram considering three different external validation methods: k-fold, leave-oneout, and bootstrap. We also analyzed prognostic variables. Performance was quantified in terms of calibration and discrimination (receiver operator characteristic curve). A logistic regression model for positive ILNs was developed based on clinicopathological features of PC. RESULTS: We analyzed 65 men who underwent ILN dissection (cN0). The mean age was 56.8 years. Of 65 men, 24 (36.9%) presented with positive LNs. A median 21 ILNs were removed. Considering the three different methods used, we concluded that the previously developed nomogram was not suitable for our sample. CONCLUSIONS: In our study, the previously developed nomogram that was applied to our population had low accuracy and low precision for correctly identifying patients with PC who have positive ILNs.
Subject(s)
Carcinoma/pathology , Inguinal Canal/pathology , Lymph Nodes/pathology , Lymphatic Metastasis/diagnosis , Nomograms , Penile Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Humans , Logistic Models , Lymph Node Excision , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Predictive Value of Tests , ROC Curve , Reference Values , Reproducibility of Results , Retrospective Studies , Risk Factors , Statistics, Nonparametric , Tumor Suppressor Protein p53/analysisABSTRACT
Prostate cancer is the second most common cancer and the fi fth leading cause of cancer deaths. In Brazil, it is likewise the second most common cancer among men, second only to non-melanoma skin cancers. The aim of this consensus is to align different opinions and interpretations of the medical literature in a practical and patient-oriented approach. The fi rst Brazilian Consensus on the Treatment of Advanced Prostate Cancer was published in 2017, with the goal of reducing the heterogeneity of therapeutic conduct in Brazilian patients with metastatic prostate cancer. We acknowledge that in Brazil the incorporation of different technologies is a big challenge, especially in the Sistema Único de Saúde (SUS), which allows for the disparity in the options available to patients treated in different institutions. In order to update the recommendations and to make them objective and easily accessible, once more a panel of specialists was formed in order to discuss and elaborate a new Brazilian Consensus on Advanced Prostate Cancer. This Consensus was written through a joint initiative of the Brazilian Society of Clinical Oncology (SBOC) and the Brazilian Society of Urology (SBU) to support the clinical decisions of physicians and other health professionals involved in the care of patients with prostate cancer.
Subject(s)
Consensus , Practice Guidelines as Topic , Prostatic Neoplasms/therapy , Antineoplastic Agents/therapeutic use , Brazil , Clinical Decision-Making , Humans , Male , Neoplasm Metastasis , Prostatic Neoplasms/pathology , Societies, MedicalSubject(s)
Prostatic Neoplasms , Dissection , Humans , Male , Prostatectomy , Prostatic Neoplasms/surgeryABSTRACT
PURPOSE: The morbidity associated with metabolic syndrome induced by androgen deprivation therapy (ADT) in prostate cancer (PCa) has not been widely studied. There are no studies comparing surgical and pharmacological castration with regards to their metabolic side effects. The aim of this study was to compare both modalities. METHODS: A prospective observational study was conducted in men with PCa and with indications of any ADT. The participants were divided into two groups: (1) bilateral orchiectomy and (2) LHRH analogs. The metabolic profile was assessed before and during the period of ADT. Bioelectrical impedance analysis (BIA) and bone mineral density were measured before and after 6 months of treatment. The data were analyzed using the Chi-squared test, Student's t test, Bonferroni's test, and ANOVA. RESULTS: We enrolled 102 men for analysis, of whom 46 (54.9 %) had been subjected to bilateral orchiectomy and 56 (54.9 %) had been subjected to treatment with LHRH analogs. The basal metabolic profile, body mass index, and BIA were similar between the two groups. The oncologic control (PSA and testosterone) was also similar in both groups. In the intergroup comparison, insulin resistance (p = 0.044) and hemoglobin (p = 0.001) were worse in the group that used LHRH analogs, which was mainly diabetic patients (p = 0.007). CONCLUSION: This study showed that LHRH analogs had worse effects relative to insulin resistance, mainly in diabetic patients, and induced more anemia and bone demineralization compared to surgical castration. Further prospective, randomized, and comparative studies are needed for metabolic syndrome in ADT modalities.
Subject(s)
Antineoplastic Agents, Hormonal/adverse effects , Gonadotropin-Releasing Hormone/analogs & derivatives , Metabolic Syndrome/chemically induced , Orchiectomy/adverse effects , Prostatic Neoplasms/surgery , Aged , Aged, 80 and over , Antineoplastic Agents, Hormonal/therapeutic use , Brazil/epidemiology , Follow-Up Studies , Humans , Incidence , Insulin Resistance , Male , Metabolic Syndrome/epidemiology , Middle Aged , Prospective Studies , Prostate-Specific Antigen/blood , Prostatic Neoplasms/metabolism , Risk Factors , Testosterone/metabolismSubject(s)
Carcinoma , Urinary Bladder Neoplasms , Cystectomy , Feasibility Studies , Fiducial Markers , Humans , Muscles , Urinary Bladder , Urinary Bladder Neoplasms/surgeryABSTRACT
BACKGROUND: Prostate cancer is the most common cancer in older men in the United States (USA) and Western Europe. Androgen deprivation (AD) constitutes, in most cases, the first-line of treatment for these cases. The negative impact of CAD in quality of life, secondary to the adverse events of sustained hormone deprivation, plus the costs of this therapy, motivated the intermittent treatment approach. The objective of this study is to to perform a systematic review and meta-analysis of all randomized controlled trials that compared the efficacy and adverse events profile of intermittent versus continuous androgen deprivation for locally advanced, recurrent or metastatic hormone-sensitive prostate cancer. METHODS: Several databases were searched, including MEDLINE, EMBASE, LILACS, and CENTRAL. The endpoints were overall survival (OS), cancer-specific survival (CSS), time to progression (TTP) and adverse events. We performed a meta-analysis (MA) of the published data. The results were expressed as Hazard Ratio (HR) or Risk Ratio (RR), with their corresponding 95% Confidence Intervals (CI 95%). RESULTS: The final analysis included 13 trials comprising 6,419 patients with hormone-sensitive prostate cancer. TTP was similar in patients who received intermittent androgen deprivation (IAD) or continuous androgen deprivation (CAD) (fixed effect: HR = 1.04; CI 95% = 0.96 to 1.14; p = 0.3). OS and CSS were also similar in patients treated with IAD or CAD (OS: fixed effect: HR = 1.02; CI 95% = 0.95 to 1.09; p = 0.56 and CSS: fixed effect: HR = 1.06; CI 95% = 0.96 to 1.18; p = 0.26). CONCLUSION: Overall survival was similar between IAD and CAD in patients with locally advanced, recurrent or metastatic hormone-sensitive prostate cancer. Data on CSS are weak and the benefits of IAD on this outcome remain uncertain. Impact in QoL was similar for both groups, however, sexual activity scores were higher and the incidence of hot flushes was lower in patients treated with IAD.
Subject(s)
Androgen Antagonists/administration & dosage , Androgen Antagonists/adverse effects , Neoplasm Recurrence, Local/prevention & control , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/secondary , Sexual Dysfunction, Physiological/etiology , Sexual Dysfunction, Physiological/mortality , Causality , Comorbidity , Disease-Free Survival , Humans , Male , Neoplasm Recurrence, Local/mortality , Prevalence , Prostatic Neoplasms/mortality , Quality of Life , Risk Factors , Treatment OutcomeABSTRACT
Prostate cancer (PCa) is an immunologically cold tumor and the molecular processes that underlie this behavior are poorly understood. In this study, we investigated a primary cohort of intermediate-risk PCa (n = 51) using two NanoString profiling panels designed to study cancer progression and immune response. We identified differentially expressed genes (DEGs) and pathways associated with biochemical recurrence (BCR) and clinical risk. Confirmatory analysis was performed using the TCGA-PRAD cohort. Noteworthy DEGs included collagens such as COL1A1, COL1A2, and COL3A1. Changes in the distribution of collagens may influence the immune activity in the tumor microenvironment (TME). In addition, immune-related DEGs such as THY1, IRF5, and HLA-DRA were also identified. Enrichment analysis highlighted pathways such as those associated with angiogenesis, TGF-beta, UV response, and EMT. Among the 39 significant DEGs, 11 (28%) were identified as EMT target genes for ZEB1 using the Harmonizome database. Elevated ZEB1 expression correlated with reduced BCR risk. Immune landscape analysis revealed that ZEB1 was associated with increased immunosuppressive cell types in the TME, such as naïve B cells and M2 macrophages. Increased expression of both ZEB1 and SNAI1 was associated with elevated immune checkpoint expression. In the future, modulation of EMT could be beneficial for overcoming immunotherapy resistance in a cold tumor, such as PCa.
ABSTRACT
BACKGROUND: The median age for Prostate Cancer (PCa) diagnosis is 66 years, but 10% are diagnosed before 55 years. Studies on early-onset PCa remain both limited and controversial. This investigation sought to identify and characterize germline variants within Brazilian PCa patients classified as either early or later onset disease. METHODS: Peripheral blood DNA from 71 PCa patients: 18 younger (≤ 55 years) and 53 older (≥ 60 years) was used for Targeted DNA sequencing of 20 genes linked to DNA damage response, transcriptional regulation, cell cycle, and epigenetic control. Subsequent genetic variant identification was performed and variant functional impacts were analyzed with in silico prediction. RESULTS: A higher frequency of variants in the BRCA2 and KMT2C genes across both age groups. KMT2C has been linked to the epigenetic dysregulation observed during disease progression in PCa. We present the first instance of KMT2C mutation within the blood of Brazilian PCa patients. Furthermore, out of the recognized variants within the KMT2C gene, 7 were designated as deleterious. Thirteen deleterious variants were exclusively detected in the younger group, while the older group exhibited 37 variants. Within these findings, 4 novel variants emerged, including 1 designated as pathogenic. CONCLUSIONS: Our findings contribute to a deeper understanding of the genetic factors associated with PCa susceptibility in different age groups, especially among the Brazilian population. This is the first investigation to explore germline variants specifically in younger Brazilian PCa patients, with high relevance given the genetic diversity of the population in Brazil. Additionally, our work presents evidence of functionally deleterious germline variants within the KMT2C gene among Brazilian PCa patients. The identification of novel and functionally significant variants in the KMT2C gene emphasizes its potential role in PCa development and warrants further investigation.
Subject(s)
Prostatic Neoplasms , Male , Humans , Aged , Brazil , Prostatic Neoplasms/pathology , Germ-Line Mutation , Mutation , Germ Cells/pathology , Genetic Predisposition to DiseaseABSTRACT
UNLABELLED: What's known on the subject? and What does the study add? In spite of its low specificity, PSA is the most widely used screening test for prostate cancer (PCa), and is considered the main cause of the stage migration recently observed. The ratio of free to total PSA (%fPSA) has been shown to increase PSA accuracy in cancer detection; however, few screening studies have systematically evaluated its role in cancer detection rates in men with PSA levels <4.0 ng/mL and normal DRE. The present study supports a possible role of %fPSA as an adjunct to screening in men with total PSA 2.5-4.0 ng/mL and normal DRE, with a marked increase in cancer detection rates in a large Brazilian PCa screening study. We believe that %fPSA maybe a useful refinement to biopsy indications in men with low PSA levels. OBJECTIVE: ⢠To evaluate the role of the free to total prostate-specific antigen ratio (%fPSA) in identifying prostate cancer (PCa) in men with a prostate-specific antigen (PSA) level of 2.5-3.9 ng/mL and a normal digital rectal examination (DRE). PATIENTS AND METHODS: ⢠A prospective PCa screening study was conducted, which included 17571 men aged ≥ 45 years, across six Brazilian states, where men were recalled for further evaluation in the case of either a suspicious DRE and/or PSA ≥ 4.0 ng/mL, or PSA 2.5-3.9 ng/mL and %fPSA ≤ 15. ⢠We evaluated the impact of a %fPSA ≤ 15 on cancer detection rates and the clinical and pathological stage of tumours in men with a normal DRE and PSA 2.5-3.9 ng/mL. RESULTS: ⢠When suspicious DRE and/or PSA ≥ 4.0 ng/mL were considered as criteria to prompt further evaluation, the cancer detection rate was 3.1%. When %fPSA ≤ 15 in men with total PSA levels of 2.5-3.9 ng/mL were considered as criteria, the PCa detection rate increased to 3.7%. Considering %fPSA ≤ 15 in men with PSA 2.5-3.9 ng/mL and normal DRE, the positive predictive value of biopsy was 31.1%. ⢠Clinical stage was more favourable among men with PSA 2.5-3.9 ng/mL, normal DRE, and %fPSA ≤ 15 compared with men with normal DRE and PSA ≥ 4.0 ng/mL (P= 0.02). ⢠Among those who underwent radical prostatectomy, pathological stage and the proportion of insignificant tumours were similar between men with PSA 2.5-3.9 ng/mL, normal DRE findings and %fPSA ≤ 15, and men with PSA ≥ 4.0 ng/mL. CONCLUSIONS: ⢠The use of %fPSA ≤ 15 as a biopsy indication in men with normal DRE and PSA 2.5-4.0 ng/mL in a PCa screening programme, increased cancer detection rates. Tumours in this subset of patients had similar pathological characteristics. ⢠Using %fPSA ≤ 15 to indicate biopsy in men with PSA 2.5-3.9 ng/mL is a useful adjunct to PCa screening.