Role of the androgen receptor in breast cancer and preclinical analysis of enzalutamide

INTRODUCTION: The androgen receptor (AR) is widely expressed in breast cancers and has been proposed as a therapeutic target in estrogen receptor alpha (ER) negative breast cancers that retain AR. However, controversy exists regarding the role of AR, particularly in ER + tumors. Enzalutamide, an AR inhibitor that impairs nuclear localization of AR, was used to elucidate the role of AR in preclinical models of ER positive and negative breast cancer. METHODS: We examined nuclear AR to ER protein ratios in primary breast cancers in relation to response to endocrine therapy. The effects of AR inhibition with enzalutamide were examined in vitro and in preclinical models of ER positive and negative breast cancer that express AR. RESULTS: In a cohort of 192 women with ER + breast cancers, a high ratio of AR:ER (≥2.0) indicated an over four fold increased risk for failure while on tamoxifen (HR = 4.43). The AR:ER ratio had an independent effect on risk for failure above ER % staining alone. AR:ER ratio is also an independent predictor of disease-free survival (HR = 4.04, 95% CI: 1.68, 9.69; p = 0.002) and disease specific survival (HR = 2.75, 95% CI: 1.11, 6.86; p = 0.03). Both enzalutamide and bicalutamide inhibited 5-alpha-dihydrotestosterone (DHT)-mediated proliferation of breast cancer lines in vitro; however, enzalutamide uniquely inhibited estradiol (E2)-mediated proliferation of ER+/AR + breast cancer cells. In MCF7 xenografts (ER+/AR+) enzalutamide inhibited E2-driven tumor growth as effectively as tamoxifen by decreasing proliferation. Enzalutamide also inhibited DHT- driven tumor growth in both ER positive (MCF7) and negative (MDA-MB-453) xenografts, but did so by increasing apoptosis. CONCLUSIONS: AR to ER ratio may influence breast cancer response to traditional endocrine therapy. Enzalutamide elicits different effects on E2-mediated breast cancer cell proliferation than bicalutamide. This preclinical study supports the initiation of clinical studies evaluating enzalutamide for treatment of AR(+) tumors regardless of ER status, since it blocks both androgen- and estrogen- mediated tumor growth

Pseudolumen Size and Perimeter in Prostate Cancer: Correlation with Patient Outcome

We demonstrated in 2011 that 61% of men with postoperative PSA failure had some cribriform pattern of prostate cancer, versus 16% of nonfailures ( OR=5.89, <.0001). That study used digitized radical prostatectomy slides from 153 men, 76 failures (≥0.2 ng/mL) matched to 77 nonfailures. The current study's hypothesis: pseudolumen size and shape variability could stratify outcome within histologic patterns (single separate acini, separate acini with undulating lumens, fused small acini, papillary, cribriform). Pseudolumens were filled digitally on image captures from previously annotated specimens. Among all 5 patterns, pseudolumen spaces averaged smaller in failures than nonfailures. After multivariate analysis controlling for stage, age, margin, cancer amount, prostate volume, and presence of individual cells (grade 5), this retained significance only for the undulating-lumens and papillary patterns. In undulating-lumens pattern, PSA failures had smaller mean pseudolumen space sizes (=.03) but larger perimeters (=.04), implying more pseudolumen irregularity. In papillary pattern, the number of pseudolumen spaces was higher in failures (=.015), space size was smaller (=.11), perimeters were smaller (=.04), and perimeter/size ratio was higher (=.02). In conclusion, digitally measured pseudolumen size and shape may associate with outcome

Racial Disparities in Expression of GDF15 and NFκB in Prostate Cancer and Benign Prostatic Epithelium

Prostate cancer (PC) outcomes are more adverse for African-American (AA) than white (W) men. Growth differentiation factor 15 (GDF15, PDF, NAG-1) is a stress-induced anti-inflammatory cytokine with immunosuppressive and tumor growth-promoting functions. GDF15 inversely regulates NFκB, a transcription factor enabling pro-inflammatory gene expression and becomes constitutively activated in androgen-independent PC. Tissue microarrays (TMAs), prepared from prostatectomy tissue at three institutions, comprised 688 cases (364 W and 324 AA). Each case included ≥3 tumor punches plus ≥3 non-neoplastic punches. TMAs were stained separately for GDF15 and NFκB and evaluated by two pathologists, using the 0-3+ scale. PC, compared to benign epithelium, had elevated mean GDF15 expression (1.93 vs. 0.99) and also, NFκB (1.18 vs. 0.96, both P&lt;0.0001). Only in AA men did PC show gradewise or stagewise altered expression of these markers. In AA men, GDF15 expression fell as stage rose in PC (P=0.007) and also in benign epithelium (P =0.003). In W men, GDF15 expression in benign epithelium fell as stage (P=0.01) and grade (P=0.01) rose. NFκB expression was higher in AA than W men only in high-grade PC (P =0.01). NFκB expression rose with increasing tumor grade only in AA men (P =0.027) and in the benign prostate component only in W men (P=0.007). Benign and tumor NFκB expression did not vary with stage. PC showed significant alterations in GDF15 and NFκB expression in accord with cancer aggressiveness in AA men only: stagewise decrease in GDF15, and gradewide increase in NFκB.  Findings suggest a disparity for immune response by race in prostate carcinogenesis

Tolerance of the Human Kidney to Isolated Controlled Ischemia

Tolerance of the human kidney to ischemia is controversial. Here, we prospectively studied the renal response to clamp ischemia and reperfusion in humans, including changes in putative biomarkers of AKI. We performed renal biopsies before, during, and after surgically induced renal clamp ischemia in 40 patients undergoing partial nephrectomy. Ischemia duration was >30 minutes in 82.5% of patients. There was a mild, transient increase in serum creatinine, but serum cystatin C remained stable. Renal functional changes did not correlate with ischemia duration. Renal structural changes were much less severe than observed in animal models that used similar durations of ischemia. Other biomarkers were only mildly elevated and did not correlate with renal function or ischemia duration. In summary, these data suggest that human kidneys can safely tolerate 30–60 minutes of controlled clamp ischemia with only mild structural changes and no acute functional loss

Interobserver variation among pathologists and refinement of criteria in distinguishing separate primary tumors from intrapulmonary metastases in lung

Multiple tumor nodules are seen with increasing frequency in clinical practice. On the basis of the 2015 WHO classification of lung tumors, we assessed the reproducibility of the comprehensive histologic assessment to distinguish second primary lung cancers (SPLCs) from intrapulmonary metastases (IPMs), looking for the most distinctive histologic features. An international panel of lung pathologists reviewed a scanned sequential cohort of 126 tumors from 48 patients and recorded an agreed set of histologic features, including tumor typing and predominant pattern of adenocarcinoma, thereby opining whether the case was SPLC, IPM, or a combination thereof. Cohen kappa statistics of 0.60 on overall assessment of SPLC or IPM indicated a good agreement. Likewise, there was good agreement (kappa score 0.64, p &lt; 0.0001) between WHO histologic pattern in individual cases and SPLC or IPM status, but the proportions diversified for histologic pattern and SPLC or IPM status (McNemar test, p &lt; 0.0001). The strongest associations for distinguishing between SPLC and IPM were observed for nuclear pleomorphism, cell size, acinus formation, nucleolar size, mitotic rate, nuclear inclusions, intraalveolar clusters, and necrosis. Conversely, the associations for lymphocytosis, mucin content, lepidic growth, vascular invasion, macrophage response, clear cell change, acute inflammation keratinization, and emperipolesis did not reach significance with tumor extent. Comprehensive histologic assessment is recommended for distinguishing SPLC from IPM with good reproducibility among lung pathologists. In addition to main histologic type and predominant patterns of histologic subtypes, nuclear pleomorphism, cell size, acinus formation, nucleolar size, and mitotic rate strongly correlate with pathologic staging status. (C) 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.N

Interobserver Variation among Pathologists and Refinement of Criteria in Distinguishing Separate Primary Tumors from Intrapulmonary Metastases in Lung

Multiple tumor nodules are seen with increasing frequency in clinical practice. On the basis of the 2015 WHO classification of lung tumors, we assessed the reproducibility of the comprehensive histologic assessment to distinguish second primary lung cancers (SPLCs) from intrapulmonary metastases (IPMs), looking for the most distinctive histologic features. An international panel of lung pathologists reviewed a scanned sequential cohort of 126 tumors from 48 patients and recorded an agreed set of histologic features, including tumor typing and predominant pattern of adenocarcinoma, thereby opining whether the case was SPLC, IPM, or a combination thereof. Cohen κ statistics of 0.60 on overall assessment of SPLC or IPM indicated a good agreement. Likewise, there was good agreement (κ score 0.64, p < 0.0001) between WHO histologic pattern in individual cases and SPLC or IPM status, but the proportions diversified for histologic pattern and SPLC or IPM status (McNemar test, p < 0.0001). The strongest associations for distinguishing between SPLC and IPM were observed for nuclear pleomorphism, cell size, acinus formation, nucleolar size, mitotic rate, nuclear inclusions, intraalveolar clusters, and necrosis. Conversely, the associations for lymphocytosis, mucin content, lepidic growth, vascular invasion, macrophage response, clear cell change, acute inflammation keratinization, and emperipolesis did not reach significance with tumor extent. Comprehensive histologic assessment is recommended for distinguishing SPLC from IPM with good reproducibility among lung pathologists. In addition to main histologic type and predominant patterns of histologic subtypes, nuclear pleomorphism, cell size, acinus formation, nucleolar size, and mitotic rate strongly correlate with pathologic staging status