Comparison of biochemical recurrence in prostate cancer patients treated with radical prostatectomy or radiotherapy

Gene signatures predict biochemical recurrence-free survival in primary prostate cancer patients after radical therapy

Background

This study evaluated the predictive value of gene signatures for biochemical recurrence (BCR) in primary prostate cancer (PCa) patients.

Methods

Clinical features and gene expression profiles of PCa patients were attained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets, which were further classified into a training set (n = 419), a validation set (n = 403). The least absolute shrinkage and selection operator Cox (LASSO‐Cox) method was used to select discriminative gene signatures in training set for biochemical recurrence‐free survival (BCRFS). Selected gene signatures established a risk score system. Univariate and multivariate analyses of prognostic factors about BCRFS were performed using the Cox proportional hazards regression models. A nomogram based on multivariate analysis was plotted to facilitate clinical application. Kyoto Encyclopedia of Gene and Genomes (KEGG) and Gene Ontology (GO) analyses were then executed for differentially expressed genes (DEGs).

Results

Notably, the risk score could significantly identify BCRFS by time‐dependent receiver operating characteristic (t‐ROC) curves in the training set (3‐year area under the curve (AUC) = 0.820, 5‐year AUC = 0.809) and the validation set (3‐year AUC = 0.723, 5‐year AUC = 0.733).

Conclusions

Clinically, the nomogram model, which incorporates Gleason score and the risk score, could effectively predict BCRFS and potentially be utilized as a useful tool for the screening of BCRFS in PCa.

Clinical verification of 18F-DCFPyL PET-detected lesions in patients with biochemically recurrent prostate cancer

Purpose

Radiolabeled Prostate-Specific Membrane Antigen (PSMA) PET/CT is the current standard-of-care for lesion detection in patients with biochemically recurrent (BCR) prostate cancer (PCa). However, rigorous verification of detected lesions is not always performed in routine clinical practice. To aid future ¹⁸F-radiolabeled PSMA PET/CT interpretation, we aimed to identify clinical/imaging characteristics that increase the likelihood that a PSMA-avid lesion is malignant.

Materials and methods

262 patients with BCR, who underwent ¹⁸F-DCFPyL PSMA PET/CT, were retrospectively analyzed. The malignant nature of ¹⁸F-DCFPyL PET-detected lesions was verified through any of the following metrics: (1) positive histopathological examination; (2) additional positive imaging; (3) a ≥50% decrease in Prostate-Specific Antigen (PSA) following irradiation of the lesion(s).

Results

In 226/262 PET scans (86.3%) at least one lesion suspicious for recurrent PCa was detected (‘positive scan’). In 84/226 positive scans (37.2%), at least one independent verification metric was available. PSMA PET-detected lesions were most often confirmed to be malignant (PCa) in the presence of a CT-substrate (96.5% vs. 55.6% without CT-substrate), with SUV_peak ≥3.5 (91.4% vs. 60.0% with SUV_peak<3.5), in patients with a PSA-level ≥2.0 ng/mL (83.7% vs. 65.7% in patients with PSA <2.0ng/mL) and in patients with >2 PET-positive lesions (94.1% vs. 64.2% in patients with 1–2 PET-positive lesions; p<0.001–0.03).

Conclusions

In this study, the clinical verification of ¹⁸F-DCFPyL PET-positive lesions in patients with BCR was performed. Diagnostic certainty of PET-detected lesions increases in the presence of characteristic abnormalities on CT, when SUV_peak is ≥3.5, when PSA-levels exceed 2.0 ng/mL or in patients with more than two PET-positive lesions.

Cause of Death in Korean Men with Prostate Cancer: an Analysis of Time Trends in a Nationwide Cohort

Despite rapid increase in incidence of prostate cancer (PC) and PC survivors, there are few studies regarding competing causes of death and time trends in Asian population. We conducted a cohort study of 2% nationwide random sample of Korean National Health Insurance employees. A total of 873 patients who had received active treatments, including surgery, radiation therapy (RT) and androgen deprivation therapy (ADT), for newly diagnosed PC between 2003 and 2010 were included. The cause of death was categorized as PC, other cancers, cardiovascular disease, and other causes. During a median follow-up of 4.75 years, 29.4% (257/873) of the study population died. PC, other cancers, cardiovascular disease, and other causes were responsible for 46.3%, 35.4%, 6.6%, and 11.7%, respectively, of the decedents. Significant differences existed in the cause of death among treatment groups (P < 0.001). Only 20% and 9.5% of surgery and RT group died of PC, whereas 63.9% of ADT group died of PC. Other cancers were responsible for 56%, 74.6% and 17.8% of death in the surgery, RT and ADT group, respectively, while cardiovascular disease accounted for 4%, 6.3%, and 7.1% of death in the treatment groups. Analysis of time trends showed that PC-specific death tended to decrease (from 42.9% in 2003 to 23.1% in 2010), whereas non-PC causes tended to increase over the 8 years. Our results are valuable in overviewing causes of death and time trends in Korean PC patients, and planning future health policy for PC.