Brian D. Robinson

Integrative clinical genomics of advanced prostate cancer

Toward development of a precision medicine framework for metastatic, castration-resistant prostate cancer (mCRPC), we established a multi-institutional clinical sequencing infrastructure to conduct prospective whole-exome and transcriptome sequencing of bone or soft tissue tumor biopsies from a cohort of 150 mCRPC affected individuals. Aberrations of AR, ETS genes, TP53, and PTEN were frequent (40%-60% of cases), with TP53 and AR alterations enriched in mCRPC compared to primary prostate cancer. We identified new genomic alterations in PIK3CA/B, R-spondin, BRAF/RAF1, APC, β-catenin, and ZBTB16/PLZF. Moreover, aberrations of BRCA2, BRCA1, and ATM were observed at substantially higher frequencies (19.3% overall) compared to those in primary prostate cancers. 89% of affected individuals harbored a clinically actionable aberration, including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. This cohort study provides clinically actionable information that could impact treatment decisions for these affected individuals.

Proposed morphologic classification of prostate cancer with neuroendocrine differentiation.

On July 31, 2013, the Prostate Cancer Foundation assembled a working committee on the molecular biology and pathologic classification of neuroendocrine (NE) differentiation in prostate cancer. New clinical and molecular data emerging from prostate cancers treated by contemporary androgen deprivation therapies, as well as primary lesions, have highlighted the need for refinement of diagnostic terminology to encompass the full spectrum of NE differentiation. The classification system consists of: Usual prostate adenocarcinoma with NE differentiation; 2) Adenocarcinoma with Paneth cell NE differentiation; 3) Carcinoid tumor; 4) Small cell carcinoma; 5) Large cell NE carcinoma; and 5) Mixed NE carcinoma - acinar adenocarcinoma. The article also highlights “prostate carcinoma with overlapping features of small cell carcinoma and acinar adenocarcinoma” and “castrate-resistant prostate cancer with small cell cancer-like clinical presentation”. It is envisioned that specific criteria associated with the refined diagnostic terminology will lead to clinically relevant pathologic diagnoses that will stimulate further clinical and molecular investigation and identification of appropriate targeted therapies.

Role of androgen receptor and associated lysine‐demethylase coregulators, LSD1 and JMJD2A, in localized and advanced human bladder cancer

Bladder cancer is approximately three times more common in men as compared to women. We and others have previously investigated the contribution of androgens and the androgen receptor (AR) to bladder cancer. JMJD2A and LSD1 are recently discovered AR coregulator proteins that mediate AR‐dependent transcription via recently described histone lysine‐demethylation (KDM) mechanisms. We used immunohistochemistry to examine JMJD2A, LSD1, and AR expression in 72 radical cystectomy specimens, resulting in evaluation of 129 tissue samples (59 urothelial carcinoma, 70 benign). We tested levels of these proteins for statistical association with clinicopathologic variables and patient survival. Expression of these markers was also assessed in human bladder cancer cell lines. The effects of pharmacological inhibition of LSD1 on the proliferation of these bladder cancer cells was determined. JMJD2A and AR levels were significantly lower in malignant versus benign urothelium, while increased LSD1 levels were observed in malignant urothelium relative to benign. A significant reduction in all three proteins occurred with cancer stage progression, including muscle invasion (JMJD2A/LSD1/AR), extravesical extension (JMJD2A/LSD1), and lymph node metastasis (JMJD2A/AR). Lower JMJD2A intensity correlated with additional poor prognostic features, including lymphovascular invasion, concomitant carcinoma in situ and tobacco usage, and predicted significantly worse overall survival. Pharmacological inhibition of LSD1 suppressed bladder cancer cell proliferation and androgen‐induced transcription. Our results support a novel role for the AR–KDM complex in bladder cancer initiation and progression, identify JMJD2A as a promising prognostic biomarker, and demonstrate targeting of the KDM activity as an effective potential approach for bladder cancer growth inhibition.

Animal Models of Human Prostate Cancer: The Consensus Report of the New York Meeting of the Mouse Models of Human Cancers Consortium Prostate Pathology Committee

Animal models, particularly mouse models, play a central role in the study of the etiology, prevention, and treatment of human prostate cancer. While tissue culture models are extremely useful in understanding the biology of prostate cancer, they cannot recapitulate the complex cellular interactions within the tumor microenvironment that play a key role in cancer initiation and progression. The National Cancer Institute (NCI) Mouse Models of Human Cancers Consortium convened a group of human and veterinary pathologists to review the current animal models of prostate cancer and make recommendations about the pathologic analysis of these models. More than 40 different models with 439 samples were reviewed, including genetically engineered mouse models, xenograft, rat, and canine models. Numerous relevant models have been developed over the past 15 years, and each approach has strengths and weaknesses. Analysis of multiple genetically engineered models has shown that reactive stroma formation is present in all the models developing invasive carcinomas. In addition, numerous models with multiple genetic alterations display aggressive phenotypes characterized by sarcomatoid carcinomas and metastases, which is presumably a histologic manifestation of epithelial-mesenchymal transition. The significant progress in development of improved models of prostate cancer has already accelerated our understanding of the complex biology of prostate cancer and promises to enhance development of new approaches to prevention, detection, and treatment of this common malignancy.

Renal epithelioid angiomyolipoma with atypia: a series of 40 cases with emphasis on clinicopathologic prognostic indicators of malignancy.

As epithelioid cellular morphology can be seen in clinically benign usual angiomyolipomas (AMLs), we divide epithelioid AMLs into those without and with atypia, the latter category associated in the literature with malignant potential. We herein report the histologic spectrum and biologic behavior of 40 consecutive cases of epithelioid AML with atypia and assess whether cases can be stratified prognostically based on clinical and pathologic features. Atypical epithelioid cells were defined as atypical polygonal cells with abundant cytoplasm, vesicular nuclei, prominent nucleoli, and nuclear size that exceeds ×2 the size of adjacent nuclei. The degree of atypia was divided to moderate and severe. Cases with bland epithelioid cells with minimal variation in nuclear size were not included. Mean age was 50.5 years (range 17 to 81), and the female to male ratio was 1.6:1. Average tumor size was 7.2 cm (range 1.0 to 17.7). The percentage of epithelioid component ranged from 5%-100% (mean 68%). Of the epithelioid component, the percentage of cells exhibiting nuclear atypia ranged in individual cases from 5% to 100% (mean of 58.4% atypical cells); 26/40 (65%) cases showed severe nuclear atypia. Cells displaying severe nuclear atypia were typically of large size with abundant cytoplasm, compared with those with moderate atypia being of small to intermediate in size with scant to moderate amount of cytoplasm. Neoplastic multinucleated giant cells and necrosis was present in 22 cases (55%) and 15 cases (37.5%), respectively. Mitoses were identified in 72.5% (29/40) of cases and ranged from 1 to 6 per 10 hpf with 7 cases showing atypical mitotic figures. Lymphovascular invasion or renal vein invasion was present in 3 cases each. Hilar and perinephric fat involvement was present in 5 and 6 cases, respectively. Clinical follow-up was available in 34 out of the 40 cases. Of the 34 cases, 9 (26%) were malignant and showed local recurrence or distant metastases. Of the 9 patients with malignant tumors, 4 died of the disease at 6, 12, 15, and 34 months after the original diagnosis was rendered, and 4 were alive with disease (mean follow-up period of 52 mo, range 24 to 72 mo). Twenty-four patients showed no evidence of recurrence and/or metastases with a mean follow-up period of 34 months (range 1 to 156 mo). We compared the 21 cases of atypical epithelioid AMLs that exhibited a benign clinical course with a minimum follow-up period of 6 months postsurgery to the 9 cases with malignant behavior. All of these were more frequently observed in clinically malignant cases: older age, larger tumor size, higher percentage of epithelioid component, severe atypia, higher percentage of atypical cells, higher mitotic count, atypical mitotic figures, necrosis, lymphovascular invasion, and renal vein invasion. Using these features, we developed a predictive model of 4 atypical features that included: (1) ≥70% atypical epithelioid cells, (2) ≥2 mitotic figures per 10 hpf, (3) atypical mitotic figures, and (4) necrosis; the presence of 3 or all of the features was highly predictive of malignant behavior. This model accurately categorized 78% of clinically malignant and 100% of the clinically benign epithelioid AMLs with atypia.

Intraductal Carcinoma of the Prostate Without Invasive Carcinoma on Needle Biopsy: Emphasis on Radical Prostatectomy Findings

PURPOSE Limited information is available on radical prostatectomy findings in men with intraductal carcinoma of the prostate on needle core biopsy in the absence of invasive prostate cancer. MATERIALS AND METHODS From the consulting files of one of us we identified 83 men in whom biopsy showed only intraductal prostate cancer. Followup was available in 66 cases. We reviewed slides in 21 radical prostatectomy cases. RESULTS Treatment was radical prostatectomy in 23 men, radiation therapy in 15, hormone therapy in 8 and radiation plus hormone therapy in 15 while 5 underwent no treatment or repeat biopsy. Of the 21 radical prostatectomies available for review findings revealed pathological stage pT3a in 8 (38%), pT3b in 3 (13%), pT2 in 8 (38%) and intraductal carcinoma without identifiable invasive cancer in 2 (10%). One patient with pT3a had a positive lymph node at surgery. Average Gleason score was 7.9. Three patients (14%) experienced post-prostatectomy biochemical failure and another (5%) had bone metastases 2.5 years after prostatectomy. In 15 prostatectomies (71%) there was extensive intraductal carcinoma, defined as greater than 10% of tumor being intraductal, including the 2 cases of intraductal carcinoma only. Of the 19 prostatectomies with invasive adenocarcinoma 16 (84%) were conventional acinar adenocarcinoma, 2 (11%) ductal adenocarcinoma, and 1 (5%) mixed ductal and acinar adenocarcinoma. CONCLUSIONS At radical prostatectomy men in whom prior biopsies showed only intraductal carcinoma of the prostate typically have high grade (Gleason score 7 or greater) invasive adenocarcinoma and most have advanced stage disease (pT3). Definitive therapy is recommended in men with intraductal carcinoma of the prostate on needle biopsy even in the absence of pathologically documented invasive prostate cancer.

Whole-Exome Sequencing of Metastatic Cancer and Biomarkers of Treatment Response

IMPORTANCE Understanding molecular mechanisms of response and resistance to anticancer therapies requires prospective patient follow-up and clinical and functional validation of both common and low-frequency mutations. We describe a whole-exome sequencing (WES) precision medicine trial focused on patients with advanced cancer. OBJECTIVE To understand how WES data affect therapeutic decision making in patients with advanced cancer and to identify novel biomarkers of response. DESIGN, SETTING, AND PATIENTS Patients with metastatic and treatment-resistant cancer were prospectively enrolled at a single academic center for paired metastatic tumor and normal tissue WES during a 19-month period (February 2013 through September 2014). A comprehensive computational pipeline was used to detect point mutations, indels, and copy number alterations. Mutations were categorized as category 1, 2, or 3 on the basis of actionability; clinical reports were generated and discussed in precision tumor board. Patients were observed for 7 to 25 months for correlation of molecular information with clinical response. MAIN OUTCOMES AND MEASURES Feasibility, use of WES for decision making, and identification of novel biomarkers. RESULTS A total of 154 tumor-normal pairs from 97 patients with a range of metastatic cancers were sequenced, with a mean coverage of 95X and 16 somatic alterations detected per patient. In total, 16 mutations were category 1 (targeted therapy available), 98 were category 2 (biologically relevant), and 1474 were category 3 (unknown significance). Overall, WES provided informative results in 91 cases (94%), including alterations for which there is an approved drug, there are therapies in clinical or preclinical development, or they are considered drivers and potentially actionable (category 1-2); however, treatment was guided in only 5 patients (5%) on the basis of these recommendations because of access to clinical trials and/or off-label use of drugs. Among unexpected findings, a patient with prostate cancer with exceptional response to treatment was identified who harbored a somatic hemizygous deletion of the DNA repair gene FANCA and putative partial loss of function of the second allele through germline missense variant. Follow-up experiments established that loss of FANCA function was associated with platinum hypersensitivity both in vitro and in patient-derived xenografts, thus providing biologic rationale and functional evidence for his extreme clinical response. CONCLUSIONS AND RELEVANCE The majority of advanced, treatment-resistant tumors across tumor types harbor biologically informative alterations. The establishment of a clinical trial for WES of metastatic tumors with prospective follow-up of patients can help identify candidate predictive biomarkers of response.

Frequent truncating mutations of STAG2 in bladder cancer

Here we report the discovery of truncating mutations of the gene encoding the cohesin subunit STAG2, which regulates sister chromatid cohesion and segregation, in 36% of papillary non-invasive urothelial carcinomas and 16% of invasive urothelial carcinomas of the bladder. Our studies suggest that STAG2 has a role in controlling chromosome number but not the proliferation of bladder cancer cells. These findings identify STAG2 as one of the most commonly mutated genes in bladder cancer.

Anatomical grades of nerve sparing: a risk-stratified approach to neural-hammock sparing during robot-assisted radical prostatectomy (RARP).

Whats known on the subject? and What does the study add?

Tumor Microenvironment of Metastasis and Risk of Distant Metastasis of Breast Cancer

BACKGROUND Tumor microenvironment of metastasis (TMEM), consisting of direct contact between a macrophage, an endothelial cell, and a tumor cell, has been associated with metastasis in both rodent mammary tumors and human breast cancer. We prospectively examined the association between TMEM score and risk of distant metastasis and compared risk associated with TMEM score with that associated with IHC4. METHODS We conducted a case-control study nested within a cohort of 3760 patients with invasive ductal breast carcinoma diagnosed between 1980 and 2000 and followed through 2010. Case patients were women who developed a subsequent distant metastasis; control subjects were matched (1:1) on age at and calendar year of primary diagnosis. TMEM was assessed by triple immunostain and IHC4 by standard methods; slides were read by pathologists blinded to outcome. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, adjusted for clinical variables. A Receiver Operating Characteristic analysis was performed, and the area under the curve was estimated. All statistical tests were two-sided. RESULTS TMEM score was associated with increased risk of distant metastasis in estrogen receptor (ER)(+)/human epidermal growth factor receptor (HER2)(-) tumors (multivariable OR high vs low tertile = 2.70; 95% CI = 1.39 to 5.26; P trend = .004), whereas IHC4 score had a borderline positive association (OR10 unit increase = 1.06; 95% CI = 1.00 to 1.13); the association for TMEM score persisted after adjustment for IHC4 score. The area under the curve for TMEM, adjusted for clinical variables, was 0.78. Neither TMEM score nor IHC4 score was independently associated with metastatic risk overall or in the triple negative or HER2(+) subgroups. CONCLUSIONS TMEM score predicted risk of distant metastasis in ER(+)/HER2(-) breast cancer independently of IHC4 score and classical clinicopathologic features.