Passow, Marie R.

AimsMucinous cystic neoplasms (MCN) are defined by the presence of an ovarian‐type stroma (OTS). Once ovarian stroma has become a requirement for the diagnosis of MCNs, studies using this criterion have disclosed that MCNs are seen almost exclusively (97%) in women. The occurrence of MCNs (with ovarian stroma) in men is exceedingly rare and raises questions about the origin of OTS and the role of hormones in tumourigenesis. This study aims to investigate the clinical and histopathological features of pancreatic or hepatic MCNs in men.Methods and resultsWe examined the MCN cases in men and compared them with age‐matched women. We further investigated MCN in premenopausal and postmenopausal women to explore the impact of hormonal status.The stromal cellularity tended to be lower in men as compared to women; however, limited numbers prevented statistical significance. Clinical presentation, tumour location, body mass index and cyst complexity were similar between men and age‐matched women, similarly in pre‐ and postmenopausal woman groups. All MCN cases, regardless of gender or hormonal status, showed OTS with positivity for oestrogen receptor (ER), androgen receptor (AR) and SF‐1 immunostains. Additionally, the presence of AR and ER‐beta in lining epithelial cells, in addition to the stromal cells, raised the probability for a potential role for local hormonal signalling in the pathogenesis of these tumours.ConclusionsMCNs in men had overlapping histopathologic and immunohistochemical profiles with those in women, regardless of menopausal status.

Abstract Androgen receptor (AR) is expressed in 80% to 90% of estrogen receptor α–positive (ER+) breast cancers. Accumulated evidence has shown that AR is a tumor suppressor and that its expression is associated with improved prognosis in ER+ breast cancer. However, both a selective AR agonist (RAD140) and an AR inhibitor (enzalutamide, ENZ) have shown a therapeutic effect on ER+ breast cancer, so the potential for clinical application of AR-targeting therapy for ER+ breast cancer is still in dispute. In this study, we evaluated the efficacy of ENZ and RAD140 in vivo and in vitro in AR+/ER+ breast cancer models, characterizing the relationship of AR and ER levels to response to AR-targeting drugs and investigating the alterations of global gene expression and chromatin binding of AR and ERα after ENZ treatment. In the AR-low setting, ENZ directly functioned as an ERα antagonist. Cell growth inhibition by ENZ in breast cancer with low AR expression was independent of AR and instead dependent on ER. In AR-high breast cancer models, AR repressed ERα signaling and ENZ promoted ERα signaling by antagonizing AR. In contrast, RAD140 activated AR signaling and suppressed AR-high tumor growth by deregulating ERα expression and blocking ERα function. Overall, analysis of the dynamic efficacies and outcomes of AR agonist, and antagonist in the presence of different AR and ERα levels reveals regulators of response and supports the clinical investigation of ENZ in selected ER+ tumors with a low AR/ER ratio and AR agonists in tumors with a high AR/ER ratio. Significance: The ratio of androgen receptor to estrogen receptor in breast cancer dictates the response to AR-targeted therapies, providing guidelines for developing AR-directed treatment strategies for patients with breast cancer.

Abstract Background: Androgen receptor (AR) is expressed in 60%-90% of breast cancers. The role of AR in breast cancer largely depends on estrogen receptor (ER) status and remains controversial. In ER+ cancers, AR expression is associated with improved prognosis. Enzalutamide (ENZ), an AR antagonist, impairs AR signaling, inhibits ER+/AR+ breast cancer cell proliferation and has been shown to mitigate resistance to anti-estrogen therapies. A recent study identified that RAD140, an AR agonist, suppressed the growth of ER+/AR+ breast cancer via stimulating AR signaling, resulting in down regulation of ERα. Both AR agonists and antagonists are effective in treating ER+ breast cancers. Identifying the subgroup of patients who most likely will benefit from an individual drug is important in clinical practice. Here, we sought to characterize the relative AR to ER levels and their relationships to drug response in ER+ breast cancers.Methods: We evaluated AR and ER expression levels among 68 samples with ER+ breast cancers. On each tumor, IHC staining for AR and ER were performed and results were scored by multiplying the percentage of positive cells by the intensity. TCGA-RPPA (reverse phase protein array) dataset was used to verify AR protein distribution in ER+ cancers. We created MCF7 and T47D cells with doxycycline-inducible AR and ER expression system to manipulate the relative AR to ER ratios and determined the antitumor activity of ENZ and RAD140 by cell proliferation assays. The levels of AR and ER in cells were measured by western blot. Linear regression was used to test the association between dose-response area under curve (AUC) and AR, ER levels. Drug preference was modeled against AR/ER expression levels (AR/ER ratios) using logistic regression.Results: Among 68 ER+ breast cancers, 69.12% were AR-positive. More than 2/3 cases (48 of 68) had more ER than AR expressed. The AR to ER ratios varied from 0 to 6. In the TCGA cohort, 84.15% of 347 ER+ patients had AR/ER ratios less than 1.The range of AR to ER ratios in TCGA dataset were comparable with our data (0.004 to 4.210). In our cell line models, the AR/ER ratios were controlled between 0.19 to 4.05. We found that the AUC of RAD140 was negatively associated with AR protein levels (P=0.008) and AR/ER ratios (P=0.013), and not significantly associated with ER expression levels. On the other hand, the AUC of ENZ was significantly negatively associated with ER protein (P=0.0016) but postiviely associated with AR/ER ratio (p=0.037). Preferred treatment comparing efficacy of the two drug can be best determined at extremes of AR/ER ratios. Using clinically relevant dosages, our model predicted that ENZ (10µM) would be a preferred treatment choice and have a better treatment efficacy compared with RAD140 when the AR/ER ratio was ≤ 0.42, whereas RAD140 (1µM) would be the preferred choice with a better treatment efficacy compared with ENZ when AR/ER ratios were ≥ 3.1 The efficacy preference of the two drugs are equivocal for AR/ER ratios between 0.42 and 3.10. Conclusion: We developed preclinical models using AR and ER expression levels to predict AR-targeting drug response. The results support the use of RAD140 in AR high patients and those with an AR/ER ratio >3.10, and enzalutamide in AR low patients and those with an AR/ER ratio <0.42. Equipoise on choice of drug was found for AR/ER ratios of 0.42-3.10. RAD140 and enzalutamide are compelling candidates for monotherapy or combination with anti-estrogen therapies in ER+/AR+ breast cancer. Future clinical validation of the models and therapeutic effect is warranted. Citation Format: Lixuan Wei, Huanyao Gao, Jia Yu, Duan Liu, Huan Zhang, Thanh Nguyen, Marie R Passow, Jodi M Carter, Richard M Weinshilboum, James N Ingle, Liewei Wang. Computational modeling of androgen receptor (AR) and estrogen receptor as predictive biomarkers of response to AR agonists and antagonists [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS5-36.

BACKGROUNDThe amount of time available to pathologists with which to perform research is becoming limited due to an increasing manpower shortage in pathology, decreased reimbursement, and increased workload. This is occurring at the same time as demands escalate for pathologists to develop new companion tests, correlate the molecular findings with traditional methods, and assist in the development of individualized medicine. This study examined whether cytotechnologists may be integrated into a research team that uses their expertise in understanding pathology and clinical disease to provide interpretations of experiments that traditionally were performed by pathologists.METHODSCytotechnologists worked with pathologists to choose blocks for tissue microarrays (TMAs) and to interpret immunohistochemically stained TMA slides. The pathologist met with the cytotechnologist to review the study design. The cytotechnologists reviewed the slides and blocks and chose the most appropriate blocks for the TMA. Either 10% or all of the slides/blocks selected for TMA construction were reviewed by the supervising pathologist. The final selections were given to the TMA technologist to make the TMA. A minimum of 10% of the immunohistochemically stained TMA slides were reviewed by the supervising pathologist.RESULTSA total of 32 TMAs were created with 6 cytotechnologists collaborating with 6 pathologists. Immunohistochemical stains of 190 TMAs were interpreted by 4 cytotechnologists collaborating with 3 pathologists. All the TMAs and TMA interpretation data were used successfully for the research for which they were designed.CONCLUSIONSThe collaboration of cytotechnologists and pathologists in research can improve the quality of effort and increase satisfaction and productivity. Cancer Cytopathol 2018;126:232‐5. © 2018 American Cancer Society.