Mucinous adenocarcinoma of the prostatic urethra after brachytherapy for prostatic adenocarcinoma: a case series.

Mucinous adenocarcinoma of the urethra is extremely rare, even more so in a setting of postradiation therapy, with only 3 cases reported up to date including the first case published by our group in 2011. In the present study, we included the long-term follow-up on our previously reported case and report 3 additional cases. This is the first case series to date of this rare disease entity. The aim of this study is to review the clinicopathologic features of mucinous adenocarcinoma of the prostatic urethra in patients after receiving brachytherapy for prostatic adenocarcinoma. We identified 4 patients with a mean age of 72 years, and a mean interval of 14.8 years from brachytherapy for prostate carcinoma (grade group 1). Patients presented with hematuria or urinary retention. A colonoscopy was performed in three-fourth of patients and was within normal limits. Three patients underwent cystoprostatectomy and 1 had a transurethral resection of the prostate. On gross examination, only tumor formed a 3.5 cm tan-gray, ulcerated, friable, and necrotic mass and 2 displayed either irregular red granular or thickened areas within the prostatic urethra. Abundant extracellular mucin pools dissecting the prostatic stroma were present in all tumors, with clusters of tumor cells floating in the mucin. The mucin pools were lined by pleomorphic pseudostratified columnar mucinous epithelium. Tumors were diffusely positive for CK20, CDX2 (4/4), and AMACR (2/2); they focally expressed CK7 (2/4), and lacked nuclear ß-catenin expression (3/3). PSA, PSAP, NKX3.1, p63, and GATA3 were negative in the tumors tested. Among the 3 patients who underwent radical surgery, 2 had stage 2 tumors (confined to the prostatic urethra and prostate), and 1 had a stage 3 tumor, with seminal vesicle involvement. All 4 patients were alive without disease with a mean follow-up of 4.9 years. In conclusion, brachytherapy-associated mucinous adenocarcinoma of the prostatic urethra displays intestinal-type features as its non-radiation-related counterpart. It appears to lack a villous adenoma component, displays a different immunohistochemical profile with diffuse CK20 and CDX2 positivity, and is associated with lower stage and less aggressive behavior.

GPD1 Enhances the Anticancer Effects of Metformin by Synergistically Increasing Total Cellular Glycerol-3-Phosphate.

Metformin is an oral drug widely used for the treatment of type 2 diabetes mellitus. Numerous studies have demonstrated the value of metformin in cancer treatment. However, for metformin to elicit effects on cancer often requires a high dosage, and any underlying mechanism for how to improve its inhibitory effects remains unknown. Here, we found that low mRNA expression of glycerol-3-phosphate dehydrogenase 1 (GPD1) may predict a poor response to metformin treatment in 15 cancer cell lines. In vitro and in vivo, metformin treatment alone significantly suppressed cancer cell proliferation, a phenotype enhanced by GPD1 overexpression. Total cellular glycerol-3-phosphate concentration was significantly increased by the combination of GPD1 overexpression and metformin treatment, which suppressed cancer growth via inhibition of mitochondrial function. Eventually, increased reactive oxygen species and mitochondrial structural damage was observed in GPD1-overexpressing cell lines treated with metformin, which may contribute to cell death. In summary, this study demonstrates that GPD1 overexpression enhances the anticancer activity of metformin and that patients with increased GPD1 expression in tumor cells may respond better to metformin therapy. SIGNIFICANCE: GPD1 overexpression enhances the anticancer effect of metformin through synergistic inhibition of mitochondrial function, thereby providing new insight into metformin-mediated cancer therapy.

Obesity-associated inflammation induces androgenic to estrogenic switch in the prostate gland.

BACKGROUND AND OBJECTIVE: Our patient cohort revealed that obesity is strongly associated with steroid-5α reductase type 2 (SRD5A2) promoter methylation and reduced protein expression. The underlying mechanism of prostatic growth in this population is poorly understood. Here we addressed the question of how obesity, inflammation, and steroid hormones affect the development of benign prostatic hyperplasia (BPH). MATERIAL AND METHODS: We used preadipocytes, macrophages, primary human prostatic stromal cells, prostate tissues from high-fat diet-induced obese mice, and 35 prostate specimens that were collected from patients who underwent transurethral resection of the prostate (TURP). RNA was isolated and quantified with RT-PCR. Genome DNA was extracted and SRD5A2 promoter methylation was determined. Sex hormones were determined by high-performance liquid chromatography-tandem mass spectrometry. Protein was extracted and determined by ELISA test. RESULTS: In prostatic tissues with obesity, the levels of inflammatory mediators were elevated. SRD5A2 promoter methylation was promoted, but SRD5A2 expression was inhibited. Inflammatory mediators and saturated fatty acid synergistically regulated aromatase activity. Obesity promoted an androgenic to estrogenic switch in the prostate. CONCLUSIONS: Our findings suggest that obesity-associated inflammation induces androgenic to estrogenic switch in the prostate gland, which may serve as an effective strategy for alternative therapies for management of lower urinary tract symptoms associated with BPH in select individuals.

Establishing a prediction model for prostate cancer bone metastasis.

We collected clinical data from 308 prostate cancer (PCa) patients to investigate the clinical characteristics and independent risk factors of bone metastasis (BM) and to establish a prediction model for BM of PCa and determine the necessity of bone scans. Univariate and multivariate analyses were performed based on age, biopsy Gleason score (BGS), clinical tumor stage (cTx), total prostate specific antigen (tPSA), free prostate specific antigen (fPSA), fPSA/tPSA, prostate volume, alkaline phosphatase (ALP), serum calcium and serum phosphorus. Moreover, 80 of the 308 PCa patients had a PI-RADS v2 score and were analysed retrospectively. The univariate analysis showed that the BGS, cTx, tPSA, fPSA, prostate volume and ALP were significant. The multivariate logistic regression analysis showed significant differences among the BGS, cTx, tPSA and ALP. Four cases should be highly suspected with BM: (i) cTl-cT2, BGS ≤7, ALP >120 U/L and tPSA >90.64 ng/ml; (ii) cTl-cT2, BGS ≥8, and ALP >120 U/L; (iii) cT3-cT4, BGS ≤7, and ALP >120 U/L; and (iv) cT3-cT4 and BGS ≥8. After the PI-RADS v2 score was included in the model, the AUC of the prediction model rose from 0.884 (95% CI: 0.813-0.996) to 0.934 (95% CI: 0.883-0.986). This model may help determine the necessity of bone scans to diagnose BM for PCa patients.

Bladder Preservation With Twice-a-Day Radiation Plus Fluorouracil/Cisplatin or Once Daily Radiation Plus Gemcitabine for Muscle-Invasive Bladder Cancer: NRG/RTOG 0712-A Randomized Phase II Trial.

PURPOSE: Fluorouracil plus cisplatin and radiation twice a day (FCT) is an established chemoradiation (CRT) regimen for selective bladder-sparing treatment of muscle-invasive bladder cancer. Gemcitabine and once daily radiation (GD) is a well-supported alternative. The current trial evaluates these regimens. METHODS: Patients with cT2-4a muscle-invasive bladder cancer were randomly assigned to FCT or GD. Patients underwent transurethral resection and induction CRT to 40 Gy. Patients who achieved a complete response (CR) received consolidation CRT to 64 Gy and others underwent cystectomy. We administered adjuvant gemcitabine/cisplatin chemotherapy. The primary end point was the rate of freedom from distant metastasis at 3 years (DMF3). The trial was not statistically powered to compare regimens, but to assess whether either regimen exceeded a DMF3 benchmark of 75%. Toxicity and efficacy end points, including CR and bladder-intact distant metastasis free survival at 3 years (BI-DMFS3), were assessed. RESULTS: From December 2008 to April 2014, 70 patients were enrolled, of which 66 were eligible for analysis, 33 per arm. Median follow-up was 5.1 years (range, 0.4 to 7.8 years) for eligible living patients. DMF3 was 78% and 84% for FCT and GD, respectively. BI-DMFS3 was 67% and 72%, respectively. Postinduction CR rates were 88% and 78%, respectively. Of 33 patients in the FCT arm, 21 (64%) experienced treatment-related grade 3 and 4 toxicities during protocol treatment, with 18 (55%), two (6%), and two patients (6%) experiencing grade 3 and 4 hematologic, GI, and genitourinary toxicity, respectively. For the 33 patients in the GD arm, these figures were 18 (55%) overall and 14 (42%), three (9%) and two patients (6%), respectively. CONCLUSION: Both regimens demonstrated DMF3 greater than 75%. There were fewer toxicities observed in the GD arm. Either gemcitabine and once daily radiation or a cisplatin-based regimen could serve as a base for future trials of systemic therapy.

Models of care and NCCN guideline adherence in very-low-risk prostate cancer.

NCCN Guidelines recommend active surveillance as the primary management option for patients with very-low-risk prostate cancer and an expected survival of less than 20 years, reflecting the favorable prognosis of these men and the lack of perceived benefit of immediate, definitive treatment. The authors hypothesized that care at a multidisciplinary clinic, where multiple physicians have an opportunity to simultaneously review and discuss each case, is associated with increased rates of active surveillance in men with very-low-risk prostate cancer, including those with limited life expectancy. Of 630 patients with low-risk prostate cancer managed at 1 of 3 tertiary care centers in Boston, Massachusetts in 2009, 274 (43.5%) had very-low-risk classification. Patients were either seen by 1 or more individual practitioners in sequential settings or at a multidisciplinary clinic, in which concurrent consultation with 2 or more of the following specialties was obtained: urology, radiation oncology, and medical oncology. Patients seen at a multidisciplinary prostate cancer clinic were more likely to select active surveillance than those seen by individual practitioners (64% vs 30%; P<.001), an association that remained significant on multivariable logistic regression (odds ratio [OR], 4.16; P<.001). When the analysis was limited to patients with an expected survival of less than 20 years, this association remained highly significant (72% vs 34%, P<.001; OR, 5.19; P<.001, respectively). Multidisciplinary care is strongly associated with selection of active surveillance, adherence to NCCN Guidelines and minimization of overtreatment in patients with very-low-risk prostate cancer.

Transurethral surgery and twice-daily radiation plus paclitaxel-cisplatin or fluorouracil-cisplatin with selective bladder preservation and adjuvant chemotherapy for patients with muscle invasive bladder cancer (RTOG 0233): a randomised multicentre phase 2 trial.

BACKGROUND: We assessed effectiveness, safety, and tolerability of paclitaxel or fluorouracil when added to radiation plus cisplatin followed by adjuvant chemotherapy in a programme of selected bladder preservation for patients with muscle invasive bladder cancer. METHODS: In our randomised phase 2 trial, we enrolled patients with T2-4a transitional cell carcinoma of the bladder at 24 medical centres in the USA. We randomly allocated patients to receive paclitaxel plus cisplatin (paclitaxel group) or fluorouracil plus cisplatin (fluorouracil group) with twice-daily radiation in random block sizes per site on the basis of clinical T-stage (T2 vs T3-4). Patients and physicians were aware of treatment assignment. All patients had transurethral resection of bladder tumour and twice-daily radiotherapy to 40·3 Gy, along with allocated chemotherapy, followed by cystoscopic and biopsy assessment of response. Patients who had a tumour response with downstaging to T0, Tcis, or Ta received consolidation chemoradiotherapy to 64·3 Gy, with the same chemotherapy regimen as in the induction phase. Patients received adjuvant cisplatin-gemcitabine-paclitaxel after the end of chemoradiotherapy. If, after induction, persistent disease was graded as T1 or worse, we recommended patients undergo cystectomy and adjuvant chemotherapy. We assessed the primary endpoints of rates of treatment completion and toxic effects in all randomly allocated patients. This study is registered with ClinicalTrials.gov, number NCT00055601. FINDINGS: Between Dec 13, 2002, and Jan 11, 2008, we enrolled 97 patients, of whom 93 were eligible for analysis. Median follow-up was 5·0 years (IQR 5·0-6·2). Of 46 patients in the paclitaxel group, 45 (98%) completed induction (16 [35%] with grade 3-4 toxicity), 39 (85%) completed induction and consolidation (11 [24%] with grade 3-4 toxicity due to consolidation), and 31 (67%) completed the entire protocol with adjuvant chemotherapy. 34 (85%) of 40 assessable patients in the paclitaxel group had grade 3-4 toxicity during adjuvant chemotherapy. Of 47 patients in the fluorouracil group, 45 (96%) completed induction (nine [19%] with grade 3-4 toxicity), 39 (83%) completed induction and consolidation (12 [26%] had grade 3-4 toxicity due to consolidation), and 25 (53%) completed the entire protocol with adjuvant chemotherapy. 31 (76%) of 41 assessable patients in the fluorouracil group had grade 3-4 toxicity during adjuvant chemotherapy. Five (11%) patients treated with the paclitaxel regimen and three (6%) patients treated with the fluorouracil regimen developed late grade 3-4 radiotherapy toxicities. 11 (24%) patients treated with the paclitaxel regimen and 16 (34%) patients treated with the fluorouracil regimen developed late grade 3-4 toxicities unrelated to radiotherapy. One patient (in the fluorouracil group) died during follow-up. Six (13%) patients in the paclitaxel group and in three (6%) patients in the fluorouracil group discontinued due to treatment-related toxicity. INTERPRETATION: In the absence of phase 3 data, our findings could inform selection of a bladder-sparing trimodality chemotherapy regimen for patients with muscle invasive bladder cancer. FUNDING: US National Cancer Institute.