Twelve-month prostate-specific antigen values and perineural invasion as strong independent prognostic variables of long-term biochemical outcome after prostate seed brachytherapy

Perineural invasion as an independent predictor of biochemical recurrence in prostate cancer following radical prostatectomy or radiotherapy: a systematic review and meta-analysis

BACKGROUND

Although numerous studies have shown that perineural invasion (PNI) is linked to prostate cancer (PCa) risk, the results have been inconsistent. This study aimed to explore the association between PNI and biochemical recurrence (BCR) in patients with PCa following radical prostatectomy (RP) or radiotherapy (RT).

METHODS

According to the PRISMA statement, we searched the PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI) and Wan Fang databases from inception to May 2017. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were extracted from eligible studies. Fixed or random effects model were used to calculate pooled HRs and 95% CIs according to heterogeneity. Publication bias was calculated by Begg's test.

RESULTS

Ultimately, 19 cohort studies that met the eligibility criteria and that involved 13,412 patients (82-2,316 per study) were included in this meta-analysis. The results showed that PNI was associated with higher BCR rates in patients with PCa after RP (HR=1.23, 95% CI: 1.11, 1.36, p<0.001) or RT (HR=1.22, 95% CI: 1.12, 1.34, p<0.001). No potential publication bias was found among the included studies in the RP group (p-Begg = 0.124) or the RT group (p-Begg = 0.081).

CONCLUSIONS

This study suggests that the presence of PNI by histopathology is associated with higher risk of BCR in PCa following RP or RT, and could serve as an independent prognostic factor in patients with PCa.

Long term outcome and side effects in patients receiving low-dose I125 brachytherapy: a retrospective analysis

Objectives:

To retrospectively evaluate the disease free survival (DFS), disease specific survival (DSS),overall survival (OS) and side effects in patients who received low-dose rate (LDR) brachytherapy with I125 stranded seeds.

Materials and methods:

Between july 2003 and august 2012, 274 patients with organ confined prostate cancer were treated with permanent I125 brachytherapy. The median follow-up, age and pretreatment prostate specific antigen (iPSA) was 84 months (12-120), 67 years (50-83) and 7.8 ng/mL (1.14-38), respectively. Median Gleason score was 6 (3-9). 219 patients (80%) had stage cT1c, 42 patients (15.3%) had stage cT2a, 3 (1.1%) had stage cT2b and 3 (1.1%) had stage cT2c. The median D90 was 154.3 Gy (102.7-190.2).

Results:

DSS was 98.5%.OS was 93.5%. 13 patients (4.7%) developed systemic disease, 7 patients (2.55%) had local progression. In 139 low risk patients, the 5 year biochemical freedom from failure rate (BFFF) was 85% and 9 patients (6.4%) developed clinical progression. In the intermediate risk group, the 5 year BFFF rate was 70% and 5 patients (7.1%) developed clinical progression. Median nPSA in patients with biochemical relapse was 1.58 ng/mL (0.21 – 10.46), median nPSA in patients in remission was 0.51 ng/mL (0.01 – 8.5). Patients attaining a low PSA nadir had a significant higher BFFF (p<0.05). Median D90 in patients with biochemical relapse was 87.2 Gy (51 – 143,1). Patients receiving a high D90 had a significant higher BFFF (p<0.05).

Conclusion:

In a well selected patient population, LDR brachytherapy offers excellent outcomes. Reaching a low PSA nadir and attaining high D90 values are significant predictors for a higher DFS.

RET Signaling in Prostate Cancer

Purpose: Large diameter perineural prostate cancer is associated with poor outcomes. GDNF, with its coreceptor GFRα1, binds RET and activates downstream pro-oncogenic signaling. Because both GDNF and GFRα1 are secreted by nerves, we examined the role of RET signaling in prostate cancer.Experimental Design: Expression of RET, GDNF, and/or GFRα1 was assessed. The impact of RET signaling on proliferation, invasion and soft agar colony formation, perineural invasion, and growth in vivo was determined. Cellular signaling downstream of RET was examined by Western blotting.Results: RET is expressed in all prostate cancer cell lines. GFRα1 is only expressed in 22Rv1 cells, which is the only line that responds to exogenous GDNF. In contrast, all cell lines respond to GDNF plus GFRα1. Conditioned medium from dorsal root ganglia contains secreted GFRα1 and promotes transformation-related phenotypes, which can be blocked by anti-GFRα1 antibody. Perineural invasion in the dorsal root ganglion assay is inhibited by anti-GFRα antibody and RET knockdown. In vivo, knockdown of RET inhibits tumor growth. RET signaling activates ERK or AKT signaling depending on context, but phosphorylation of p70S6 kinase is markedly increased in all cases. Knockdown of p70S6 kinase markedly decreases RET induced transformed phenotypes. Finally, RET is expressed in 18% of adenocarcinomas and all three small-cell carcinomas examined.Conclusions: RET promotes transformation associated phenotypes, including perineural invasion in prostate cancer via activation of p70S6 kinase. GFRα1, which is secreted by nerves, is a limiting factor for RET signaling, creating a perineural niche where RET signaling can occur. Clin Cancer Res; 23(16); 4885-96. ©2017 AACR.

Parameters predicting for prostate specific antigen response rates at one year post low-dose-rate intraoperative prostate brachytherapy

Purpose

To develop a model for prostate specific antigen (PSA) values at one year among patients treated with intraoperatively planned ¹²⁵I prostate brachytherapy (IOPB).

Material and methods

Four hundred and deven patients treated with IOPB for prostate adenocarcinoma were divided into four groups: those with PSA values ≥ 3 ng/ml; < 3 and ≥ 2; < 2 and ≥ 1 or PSA < 1 between 10.5 and 14.5 months post implantation (1yPSA). Ordinal regression analysis was then performed between patient, tumor, and treatment characteristics. 1yPSA values were also compared with toxicity outcomes.

Results

Median 1yPSA was 0.77 (0.04-17.36). Thirty-two patients (8%) had a PSA ≥ 3; 35 (9%) had PSA < 3, ≥ 2; 87 (21%) had PSA < 2, ≥ 1, and most patients 254 (62%) had PSA < 1. PSA response was independent of gland volume, Gleason score, clinical stage, seed activity, V₉₀, V₂₀₀, D₉₀, or number of needles and seeds used. Older patients had significantly lower 1yPSA; median ages 65.1 (46.5-81.0), 62.1 (50.4-79.5), 60.5 (47.1-80.3), and 58.1 (45.1-74.2) years for each of the 1yPSA groups respectively (p < 0.001). Also, both implant V₁₅₀ (p < 0.001) and initial PSA values (p = 0.04) were predictive of 1yPSA values. There was no correlation between 1yPSA values and toxicity encountered.

Conclusions

PSA response at 1 year post IOPB appears to be dependent on patient age, initial PSA, and implant V₁₅₀. Our results provide reassurance that parameters other than biochemical failure influence 1yPSA values.

Variation in reporting of cancer extent and benign histology in prostate biopsies among European pathologists

It is not known how uropathologists currently report histopathological features of prostate biopsies such as core length, tumor extent, perineural invasion, and non-tumor-associated features such as inflammation and hyperplasia in needle biopsies. A web-based survey was distributed among 661 members of the European Network of Uropathology. Complete replies were received from 266 pathologists in 22 European countries. Total core lengths were reported by 64 %. The numbers of cores positive for cancer was given by 79 %. Linear cancer extent was reported by 81 %, most often given in millimeters for each core (53 %) followed by the estimation of percentage of cancer in each core (40 %). A gap of benign tissue between separate cancer foci in a single core would always be subtracted by 48 % and by 63 % if cancer foci were minute and widely separated. Perineural invasion was reported by 97 %. Fat invasion by tumor was interpreted as extraprostatic extension by 81 %. Chronic and active/acute inflammation was always reported by 32 and 56 % but only if pronounced by 54 and 39 %, respectively. While most (79 %) would never diagnose benign prostatic hyperplasia on needle biopsy, 21 % would attempt to make this diagnosis. Reporting practices for prostate biopsies are variable among European pathologists. The great variation in some methodologies used suggests a need for further international consensus, in order for retrospective data to be comparable between different institutions.

The prognostic significance of perineural invasion and race in men considering active surveillance

OBJECTIVE

To determine the importance of perineural invasion (PNI) on diagnostic biopsy in men enrolled in active surveillance (AS).

PATIENTS AND METHODS

Eligibility criteria for AS included clinical stage ≤ T2a and Gleason score ≤6, ≤3 cores positive, maximum single core involvement <50%, and total tumour volume ≤5% on diagnostic biopsy. All men received 12-core confirmation biopsy at ≤6 months. AS 'failure' on confirmatory biopsy was defined as failure to meet one or more eligibility criteria. Risk of AS failure was compared in men with and without PNI.

RESULTS

For the 165 men comprising the study population, the mean (sd) age was 66.9 (6.5) years and the median (interquartile, IQR) PSA level of men at study entry was 4.4 (3.2-6.0) ng/mL. The median (IQR) follow-up was 5.5 (1.1-9.9) months. In all, 8.5% (14/165 men) had PNI on diagnostic biopsy. Compared with those without PNI, men with PNI tended to have more cores involved with cancer, at a mean (sd) of 2.0 (0.7) vs 1.6 (0.8) cores (P = 0.08) but did not have significantly a greater mean (sd) total tumour length on diagnostic biopsy, at 3.0 (2.1) vs 2.3 (3.6) mm (P = 0.27). Men with PNI on diagnostic biopsy were significantly more likely to meet criteria for disease progression on confirmatory biopsy (57% [8/14] vs 21% [32/151]; P = 0.006). PNI remained a significant predictor for AS failure after adjustment for number of positive cores, maximum percentage core involvement, and total tumour length (odds ratio 4.4, 95% confidence interval 1.4-14.2).

CONCLUSIONS

PNI on diagnostic biopsy is associated with disease progression on confirmatory biopsy. The presence of PNI should factor into appropriate patient selection and counselling in AS.