PTEN loss in prostatic adenocarcinoma correlates with specific adverse histologic features (intraductal carcinoma, cribriform Gleason pattern 4 and stromogenic carcinoma)

BACKGROUND

The loss of PTEN tumor suppressor gene is one of the most common somatic genetic aberrations in prostate cancer (PCa) and is frequently associated with high-risk disease. Deletion or mutation of at least one PTEN allele has been reported to occur in 20% to 40% of localized PCa and up to 60% of metastases. The goal of this study was to determine if somatic alteration detected by PTEN immunohistochemical loss of expression is associated with specific histologic features.

METHODS

Two hundred sixty prostate core needle biopsies with PCa were assessed for PTEN loss using an analytically validated immunohistochemical assay. Blinded to PTEN status, each tumor was assessed for the Grade Group (GG) and the presence or absence of nine epithelial features. Presence of stromogenic PCa was also assessed and defined as grade 3 reactive tumor stroma as previously described: the presence of carcinoma associated stromal response with epithelial to stroma ratio of greater than 50% reactive stroma.

RESULTS

Eight-eight (34%) cases exhibited PTEN loss while 172 (66%) had intact PTEN. PTEN loss was significantly (P < 0.05) associated with increasing GG, poorly formed glands (74% of total cases with loss vs 49% of intact), and three well-validated unfavorable pathological features: intraductal carcinoma of the prostate (IDC-P) (69% of total cases with loss vs 12% of intact), cribriform Gleason pattern 4 (38% of total cases with loss vs 10% of intact) and stromogenic PCa (23% of total cases with loss vs 6% of intact). IDC-P had the highest relative risk (4.993, 95% confidence interval, 3.451-7.223, P < 0.001) for PTEN loss. At least one of these three unfavorable pathological features were present in 67% of PCa exhibiting PTEN loss, while only 11% of PCa exhibited PTEN loss when none of these three unfavorable pathological features were present.

CONCLUSIONS

PCa with PTEN loss demonstrates a strong correlation with known unfavorable histologic features, particularly IDC-P. This is the first study showing the association of PTEN loss with stromogenic PCa.

The expression profile and heterogeneity analysis of ERG in 633 consecutive prostate cancers from a single center

BACKGROUND

Overexpression of ERG protein resulting from TMPRSS2:ERG rearrangement is highly specific for prostate cancer (PCa). However, the biological function of this fusion protein and its relationship with clinicopathological features still remain controversial.

METHOD

In this study, we evaluated ERG protein expression/gene rearrangement and heterogeneity by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in a cohort of 633 consecutive PCa initially diagnosed by core-needle biopsy in the West China Hospital.

RESULT

Overall, ERG protein expression was detected in 16.7% (106 of 633) cases, and frequently observed in PCa patients less than 60 years of age (31.9% vs 15.5%, P = 0.004) and in PCa with Gleason score less than 8 (20.0% vs 13.4%, P = 0.027), but infrequently observed in cases with intraductal carcinoma of the prostate (IDC-P) (10.0% vs 18.6%, P = 0.012). Follow-up analysis found that patients who progressed to castration-resistant prostate cancer (CRPC) have a lower frequency of ERG protein expression at initial biopsies compared to androgen deprivation therapy (ADT)-sensitive cases (14.1% vs 23.5%, P = 0.042), but Kaplan-Meier curve showed that ERG protein expression was not an independent prognostic marker. Of all the 106 ERG-positive cases, eight cases (7.5%) exhibited heterogeneous expression of ERG protein, in which ERG was only positive in tumors with Gleason pattern 3, but negative in Gleason pattern 4. The FISH analysis was consistent with IHC in six of these cases. In the other two cases, ERG rearrangement was detected in tumors with both Gleason pattern 3 and 4 by FISH, despite the negative protein expression in Gleason pattern 4. In case 1, a repeated biopsy was performed when the disease progressed to CRPC, and no ERG-positive cells were identified neither by IHC nor FISH.

CONCLUSION

This was by far the largest series of ERG expression and heterogeneity analysis in Chinese PCa. The ERG rearrangement seemed to be frequently expressed in patients with relatively younger age and lower Gleason score and infrequently expressed in PCa with the IDC-P. PCa with positive ERG were less frequently to progress to CRPC, but there was no prognostic significance of ERG expression. In heterogeneous cases, ERG protein was detectable only in tumors with Gleason pattern 3 but not in pattern 4. Tumor cells with positive ERG expression/rearrangement seemed easily response to ADT.

Promoter hypermethylation in ductal carcinoma in situ of the male breast

Ductal carcinoma in situ (DCIS) of the male breast is very rare and has hardly been studied molecularly. In males, we compared methylation status of 25 breast cancer-related genes in pure DCIS (n = 18) and invasive breast carcinoma (IBC) with adjacent DCIS (DCIS-AIC) (n = 44) using methylation-specific multiplex ligation-dependent probe amplification. Results were compared to female breast cancer (BC). There were no significant differences in methylation features between male pure DCIS, DCIS-AIC and IBC after correction for multiple comparisons. In paired analysis of IBC and adjacent DCIS, CADM1 showed a significantly higher absolute methylation percentage in DCIS (P = 0.002). In cluster analysis, two clusters stood out with respectively infrequent and frequent methylation (GATA5, KLLN, PAX6, PAX5, CDH13, MSH6 and WT1 were frequently methylated). Compared to female DCIS, methylation was in general much less common in male DCIS, especially for VHL, ESR1, CDKN2A, CD44, CHFR, BRCA2, RB1 and STK11. In contrast, THBS1 and GATA5 were more frequently methylated in male DCIS. In conclusion, there is frequent methylation of GATA5, KLLN, PAX6, PAX5, CDH13, MSH6 and WT1 in male DCIS. Since there was little change in the methylation status for the studied genes from pure male DCIS to DCIS-AIC and IBC, methylation of these seven genes is more likely to occur early in male breast carcinogenesis. Based on the current markers male DCIS seems to be an epigenetically more advanced precursor of male BC, although in comparison to its female counterpart it appears that fewer loci harbor methylation, pointing to differences between male and female breast carcinogenesis with regard to the studied loci.

A breast one-patient panel of heterogeneous genomes reveals genetic alterations driving DCIS into invasive lesions

Aim: Utilize breast cancer samples in the same patient to indicate breast cancer development. Patients & methods: We performed whole-exome analysis of spatially independent ductal carcinoma in situ (DCIS) and invasive ductal carcinoma samples from the same breast. Results: In VEGF pathway, we observed two genes disrupted in DCIS, while another four (including ACTN2) mutated in invasive ductal carcinoma. When looked up TCGA database, we identified seven breast cancer patients with ACTN2 somatic mutations and observed a dramatic decrease in the overall survival time in ACTN2 mutant patients (p = 0.0182). A further finding in the TCGA database shows that breast cancer patients with ≥2 mutated genes in VEGF pathways showed worse prognosis (p = 0.0013). Conclusion: TCGA database and special case could inform each other to reveal DCIS developmental rules.

Biological Aggressiveness of Subclinical No-Mass Ductal Carcinoma In Situ (DCIS) Can Be Reflected by the Expression Profiles of Epithelial-Mesenchymal Transition Triggers

Epithelial-mesenchymal transitions (EMTs) have been recently implicated in the process of cancer progression. The aim of this study was to assess how the preoperative expression patterns of EMT biomarkers correlate with the risk of postoperative invasion in ductal carcinoma in situ (DCIS) found on stereotactic breast biopsies. N-cadherin, Snail1, and secreted protein acidic and rich in cysteine (SPARC) immunoreactivity was observed in 8%, 62%, and 38% of tumors, respectively. Snail1 and SPARC expressions were significantly related to N-cadherin expression and to each other. The postoperative upgrading rate was associated with a positive preoperative expression of all biomarkers. Significance of Snail1 and SPARC persisted in multivariate analysis, but the impact of SPARC on invasion was more significant. When these two EMT triggers were considered together, the risk of invasion did not significantly differ between the subtypes of DCIS with single positive expression (SPARC−/Snail1+ vs. SPARC+/Snail1−). However, it was significantly lower in single-positive DCIS when compared to lesions of a double-positive profile (SPARC+/Snail1+). Moreover, there were no cases in the double-negative DCIS (SPARC−/Snail1−), with foci of infiltrating cancer found postoperatively in residual postbiopsy lesions. In contrast, DCIS with a combined high SPARC and Snail1 expression (intermediate or strong) had an invasive component in 66–100% of tumors.

Breaking through to the Other Side: Microenvironment Contributions to DCIS Initiation and Progression

Refinements in early detection, surgical and radiation therapy, and hormone receptor-targeted treatments have improved the survival rates for breast cancer patients. However, the ability to reliably identify which non-invasive lesions and localized tumors have the ability to progress and/or metastasize remains a major unmet need in the field. The current diagnostic and therapeutic strategies focus on intrinsic alterations within carcinoma cells that are closely associated with proliferation. However, substantial accumulating evidence has indicated that permissive changes in the stromal tissues surrounding the carcinoma play an integral role in breast cancer tumor initiation and progression. Numerous studies have suggested that the stromal environment surrounding ductal carcinoma in situ (DCIS) lesions actively contributes to enhancing tumor cell invasion and immune escape. This review will describe the current state of knowledge regarding the mechanisms through which the microenvironment interacts with DCIS lesions focusing on recent studies that describe the contributions of myoepithelial cells, fibroblasts and immune cells to invasion and subsequent progression. These mechanisms will be considered in the context of developing biomarkers for identifying lesions that will progress to invasive carcinoma and/or developing approaches for therapeutic intervention.

Expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and Ki-67 in ductal carcinoma in situ (DCIS) and DCIS with microinvasion

Ductal carcinoma in situ (DCIS) represents a heterogeneous disease in its histologic appearance and biological potential. Some women treated for DCIS subsequently develop invasive breast cancer. DCIS with microinvasion is considered as the interim stage in the progression from DCIS to invasive breast cancer. Analysis of the differences between DCIS and DCIS with microinvasion may aid in understanding the characteristic of DCIS with microinvasion and identifying biological factors determining progression of DCIS to invasive disease.Retrospective analysis of 219 cases between 2012 and 2018 was performed in our institution. The pathological results and axillary lymph nodes status were collected. Analysis of the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 in pure DCIS (164 cases), and DCIS with microinvasion (55 cases) using immunohistochemistry.DCIS with microinvasion had a higher nuclear grade (P < .001) and was more likely to have sentinel lymph node biopsy (SLNB) positivity (P = .039) than DCIS. Expression of ER, PR were significantly higher in DCIS compared with DCIS with microinvasion (P < .001, P < .001). While the expression of HER-2 in DCIS with microinvasion (56.4%) was significantly higher than in DCIS (36.6%, P = .01). Furthermore, DCIS with microinvasion was significantly more likely to have aggressive subtype (Triple-negative and HER2-enriched tumors, P = .005).Our results indicated that DCIS with microinvasion was different from pure DCIS in clinicopathologic characteristics and molecular alterations. It displayed a more aggressive biological nature than pure DCIS. It may be a distinct entity.

Differential Expression of Cancer-Associated Fibroblast-Related Proteins in Ductal Carcinoma in situ According to Molecular Subtype and Stromal Histology

OBJECTIVE

The purpose of this study is to investigate the expression of cancer-associated fibroblast (CAF)-related proteins and their implication in ductal carcinoma in situ (DCIS).

METHODS

We constructed a tissue microarray of 223 cases of DCIS and examined immunohistochemical staining for the 7 CAF-related proteins. We classified DCIS into luminal type, human epidermal growth factor receptor-2 (HER-2) type, and triple negative breast cancer (TNBC) according to the immunohistochemical results for estrogen receptor, progesterone receptor, and HER-2. We also classified DCIS into desmoplastic, normal-like, and inflammatory type according to stromal histology.

RESULTS

There were significant differences in the expression of S100A4, podoplanin, prolyl 4-hydroxylase subunit alpha 3, NG2, and PDGFRα in stromal cells of DCIS when classified according to molecular subtype. The expression rate of all CAF-related proteins in stromal cells was higher in the HER-2 type and TNBC than in the luminal type (p < 0.001). When classified according to stromal subtype, there were significant differences in the expression of all CAF-related proteins in stromal cells, with the inflammatory stromal type showing higher expression of CAF-related proteins than other stromal types.

CONCLUSION

The expression of CAF-related proteins in stromal cells of DCIS varies according to molecular subtype and stromal type.

COX-2 Expression in Breast Carcinoma with Correlation to Clinicopathological Parameters

Objective: Breast carcinoma is the most common malignant tumor and the leading cause of carcinoma deaths in women. Its etiology is multifactorial, implicating reproductive factors, hormonal imbalances and genetic predispositions. Studies have shown that Cycloxygenase-2 (COX-2) plays an important role in the carcinogenesis and increased expression has been regarded as a poor prognostic factor. The objective of our study is 1. To study COX-2 expression in normal breast tissue, DCIS and invasive breast cancer. 2. To determine COX-2 expression with clinicopathological prognostic parameters. Methods: Radical mastectomy specimens were studied for COX-2 expression by immunohistochemistry in 50 patients diagnosed as breast carcinoma. COX-2 expression is quantified as IHS Score and separately calculated for normal breast epithelium near the tumor, DCIS and invasive areas. Relationship between COX-2 expression with various clinicopathological parameters was evaluated. Result: The results of our study suggest an association of the expression of COX-2 to the factors associated with poor prognosis in breast cancer, such as larger tumor size, positive lymph node status, higher T stage and N stage and lymphovascular invasion. There was a higher COX-2 expression in the DCIS component as compared to the invasive ductal carcinoma component and the adjoining breast epithelium. Conclusion: Our study established the role of COX-2 in carcinogenesis and its association with adverse prognostic factors.

The effect of size and polymer architecture of doxorubicin-poly(ethylene) glycol conjugate nanocarriers on breast duct retention, potency and toxicity

Although systemic administration of chemotherapeutic agents is routinely used for treating invasive breast cancer, the only therapeutic options for ductal carcinoma in situ (DCIS) are surgery and radiation. Treating DCIS by delivering drugs locally to the affected milk duct offers significant advantages over systemic administration, including reduced systemic and breast toxicities, as well as a greatly reduced need for surgery and radiation. In this study, mammary gland retention and toxicity of intraductally administered poly(ethylene) glycol-doxorubicin (PEG-DOX) polymeric conjugate nanocarriers of varying molecular sizes and architectures were investigated. Nanocarriers were formed by conjugating one or more copies of doxorubicin to PEG polymers, of varying molecular weights (5, 10, 20, and 40 kDa) and architectures (linear, four-arm and eight-arm). Cytotoxicity against MCF7 cells, a human breast cancer cell line, was assessed, and IC₅₀ values were calculated. The nanocarriers were intraductally administered into the mammary glands of female retired breeder Sprague-Dawley rats. Whole body images were captured using in vivo optical imaging, and changes in ductal structure as well local inflammation were monitored. Fluorescence intensities were monitored, over time, to evaluate nanocarrier mammary gland retention half-lives (t_1/2). The IC₅₀ values of PEG-DOX nanocarriers against MCF7 cells were 40 kDa PEG-(DOX)₄ (1.23 μM) < 5 kDa PEG-DOX (1.76 μM) < 40 kDa PEG-(DOX)₈ (3.49 μM) < 10 kDa PEG-DOX (3.86 μM) < 20 kDa PEG-DOX (8.96 μM) < 40 kDa PEG-DOX (18.11 μM), whereas the IC₅₀ of free DOX was only 0.14 μM. The t_1/2 of linear 5, 20, and 40 kDa nanocarriers were 2.2 ± 0.3, 3.6 ± 0.6, and 13.1 ± 3.4 h, whereas the retention t_1/2 of 4- and 8-arm 40 kDa nanocarriers were 14.9 ± 5.6 h and 11.9 ± 2.9 h, respectively. The retention t_1/2 of free doxorubicin was 2.0 ± 0.4 h, which was significantly shorter than that of the linear and branched 40 kDa PEG-DOX nanocarriers. Increased molecular weight and decreased branching both demonstrated a strong correlation to enhanced mammary gland retention. Intraductally administered free doxorubicin resulted in ductal damage, severe inflammation and generation of atypical cell neoplasms, whereas PEG-DOX nanocarriers induced only minor and transient inflammation (i.e., damaged epithelial cells and detached cellular debris). The 40 kDa 4-arm PEG-DOX nanocarrier demonstrated the longest ductal retention half-life, the lowest IC₅₀ (i.e., most potent), and minimal ductal damage and inflammation. The current results suggest that PEG-DOX nanocarriers with prolonged ductal retention may present the best option for intraductal treatment of DCIS, due to their low local toxicity and potential for sustained therapeutic effect.

Expression of immune checkpoint regulators, cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed death-ligand 1 (PD-L1), in female breast carcinomas

BACKGROUND

Immune checkpoint regulators, cytotoxic T lymphocyte antigen 4 (CTLA-4) and the programmed cell death protein-1/programmed death-ligand 1 (PD-1/PD-L1) have emerged as promising new targets for cancer therapeutics. While tumor expression of PD-L1 has been shown to have objective responses to anti-PD-L1 immunotherapies, the clinical implications of CTLA-4 expression in tumor cells or immune cells in the tumor microenvironment is still controversial. We investigated the expression of CTLA-4 and PD-L1 in human breast tumors and provided a scoring system for the systematic evaluation of CTLA-4 staining.

METHODS

Immunohistochemical staining for PD-L1 and CTLA-4 expression was performed on a tissue microarray of 102 cores, which included normal and neoplastic breast tissues. Neoplastic cores were divided into four groups: Ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC) and invasive tubular carcinoma (ITC). PD-L1 and CTLA-4 expressions were scored based on a system which accounted for the percentage and intensity of positivity and results provided in conjunction with available clinical and demographic data.

RESULTS

Overall, CTLA-4 was over-expressed in 49 of 93 (52.7%) breast tumors. Subcategorically, CTLA-4 was positive in 3 of 8 (37.5%) ductal carcinoma in situ, 40 of 73 (55%) of invasive ductal carcinomas, 4 of 10 (40%) of invasive lobular carcinomas and 2 of 2 (100%) of invasive tubular carcinomas. All 6 normal breast tissues were interpreted as negative for CTLA-4 staining. Only 4.1% of the invasive ductal carcinomas were positive for PD-L1 reactivity and the remaining carcinomas stained negative.

CONCLUSIONS

This study shows a significant overexpression of CTLA-4 in >50% of breast carcinomas with no such overexpression of CTLA-4 in benign breast tissues. PDL-1 staining is seen in only a small number of invasive ductal carcinomas (4.1%). These findings suggest the need for further investigation of anti-CTLA-4 and anti-PD-L1 immunotherapies and their efficacy in the treatment of breast carcinomas with overexpression of these immune modulators. In addition, the proposed scoring system will facilitate a more systematic correlation between tumor reactivity and clinical outcome which can be applied to all intracytoplasmic tumor markers.

Histology and Cytometrics in Human Breast Cancers Assayed for the Presence of Prolactin Receptors

Histology and cytometrics were evaluated in 50 cases of human breast infiltrating carcinomas (44 ductal, 6 lobular) assayed for the presence of prolactin receptors (PR). The tumors were considered PR positive when the level of specific binding reached or exceeded 0.5 %. Twenty-six ductal infiltrating carcinomas and 4 lobular ones were PR positive. No strict correlation was found between PR and degree of histologic differentiation (expressed in grades) or menopausal status. Better differentiated (grade I) ductal carcinomas were, however, mostly PR negative. Evaluation of the mean nuclear diameter (MND) and of the maximal epithelial cellularity (MEC) revealed that in ductal carcinomas a high level of PR (> 3 % specific binding) was significantly correlated with a high MND. It is concluded that, contrary to that observed in estrogen receptor-positive tumors, PR-positive human ductal carcinomas are more likely to have large nuclei, i.e., cytologically anaplastic, whereas better differentiated (grade I) carcinomas are generally PR negative.

A Combined Histological, Immunocytochemical and Biochemical Approach in the Evaluation of Estrogen Receptors in Breast Carcinomas

Correlation of structural and functional data might lead to better identification of hormone-dependent tumors. Sixty breast cancer specimens, sent to the biochemistry laboratory for estrogen receptor (ER) analysis, were studied here by a combined morpho-functional approach.

Histological examination of needle biopsies on frozen tissue blocks showed that 12 cases (10%) were free of tumor cells; these cases mostly proved ER negative. On the other 48 cases, an immunocytochemical reaction was performed on the biopsy sections with a monoclonal antibody directed against p 29, an estrogen receptor related antigen. The staining values for p 29 and the biochemical ER findings were significantly correlated.

A combined histological, immunocytochemical study seems to offer advantages in the selection of patients for hormonal therapy.

Early Detection of Ductal Breast Cancer: The Diagnostic Procedure for Pathological Discharge from the Nipple

Pathologic discharge from the nipple may be the only symptom of an early stage of carcinoma. Galactography is then the diagnostic method of choice to locate intraductal, nonpalpable lesions. The technique of galactography, the adequate surgical approach of pathologic galactographs (milk-duct segment resection), and the appropriate histological work-up of the surgical specimen are demonstrated. We report on 1918 galactographies in 1363 women with pathological discharge. In only 427 cases was a milk duct segment resection necessary (31.4%). In 8.5%, we found invasive intraductal cancer and in 2.9% ductal carcinomata in situ. Only 1 patient with breast cancer had axillary metastases. Extensive intraductal solid, papillary or adenomatous proliferations were found in 11.9% of the patients with excision. In 46.7% of the patients, papillomas were excised, a definitive treatment for this process. The supposition for success in the early diagnosis of cancer is close teamwork among the radiology, surgery and pathology services: the diagnostic result depends upon this. We attribute our yield of exact diagnosis to a very sophisticated histological work-up. We believe that this is necessary to avoid diagnostic failures.

Correlative imaging reveals physiochemical heterogeneity of microcalcifications in human breast carcinomas

Microcalcifications (MCs) are routinely used to detect breast cancer in mammography. Little is known, however, about their materials properties and associated organic matrix, or their correlation to breast cancer prognosis. We combine histopathology, Raman microscopy, and electron microscopy to image MCs within snap-frozen human breast tissue and generate micron-scale resolution correlative maps of crystalline phase, trace metals, particle morphology, and organic matrix chemical signatures within high grade ductal carcinoma in situ (DCIS) and invasive cancer. We reveal the heterogeneity of mineral-matrix pairings, including punctate apatitic particles (<2 µm) with associated trace elements (e.g., F, Na, and unexpectedly Al) distributed within the necrotic cores of DCIS, and both apatite and spheroidal whitlockite particles in invasive cancer within a matrix containing spectroscopic signatures of collagen, non-collagen proteins, cholesterol, carotenoids, and DNA. Among the three DCIS samples, we identify key similarities in MC morphology and distribution, supporting a dystrophic mineralization pathway. This multimodal methodology lays the groundwork for establishing MC heterogeneity in the context of breast cancer biology, and could dramatically improve current prognostic models.

Cell Kinetics and Tumor-Associated Antigen Expression in Human Mammary Carcinomas

Twenty-six primary breast carcinomas were studied to evaluate cell proliferation as assessed by thymidine labeling index (TLI), and antigenic phenotype, as defined by immunohistochemistry using eight monoclonal antibodies (MAbs) to tumor-associated antigens (TAAs). The majority of tumors had low TLI values. Reactivity to MAbs B72.3, CC49, CC83 (anti TAG 72), COL-12 (anti CEA) and MOv2 (against a tumor-associated mucoprotein) was restricted to < 50% of the tumors studied, while MAbs B1.1 (anti CEA), MBrl and MBr8 (to tumor-associated carbohydrates) reacted with > 50% of the cases. Correlations between expression of TAAs and proliferative activity showed that the tumors could be divided into three groups, two characterized by either high proliferative activity and absence of antigenic expression or low proliferative activity and strong antigenic expression, and the third showing no relation between these two biological features. We defined two antigenic phenotypes associated with specific cellular kinetics: one characterized by negative immunoreaction with MAbs, CC49, CC83 and COL-12 and high proliferative activity; the other characterized by intense immunoreactivity with these antibodies and low proliferative activity. The data suggest that cell proliferation and antigenic phenotype may define biologic subsets of breast carcinomas

PhysiCell: An open source physics-based cell simulator for 3-D multicellular systems

Many multicellular systems problems can only be understood by studying how cells move, grow, divide, interact, and die. Tissue-scale dynamics emerge from systems of many interacting cells as they respond to and influence their microenvironment. The ideal "virtual laboratory" for such multicellular systems simulates both the biochemical microenvironment (the "stage") and many mechanically and biochemically interacting cells (the "players" upon the stage). PhysiCell-physics-based multicellular simulator-is an open source agent-based simulator that provides both the stage and the players for studying many interacting cells in dynamic tissue microenvironments. It builds upon a multi-substrate biotransport solver to link cell phenotype to multiple diffusing substrates and signaling factors. It includes biologically-driven sub-models for cell cycling, apoptosis, necrosis, solid and fluid volume changes, mechanics, and motility "out of the box." The C++ code has minimal dependencies, making it simple to maintain and deploy across platforms. PhysiCell has been parallelized with OpenMP, and its performance scales linearly with the number of cells. Simulations up to 105-106 cells are feasible on quad-core desktop workstations; larger simulations are attainable on single HPC compute nodes. We demonstrate PhysiCell by simulating the impact of necrotic core biomechanics, 3-D geometry, and stochasticity on the dynamics of hanging drop tumor spheroids and ductal carcinoma in situ (DCIS) of the breast. We demonstrate stochastic motility, chemical and contact-based interaction of multiple cell types, and the extensibility of PhysiCell with examples in synthetic multicellular systems (a "cellular cargo delivery" system, with application to anti-cancer treatments), cancer heterogeneity, and cancer immunology. PhysiCell is a powerful multicellular systems simulator that will be continually improved with new capabilities and performance improvements. It also represents a significant independent code base for replicating results from other simulation platforms. The PhysiCell source code, examples, documentation, and support are available under the BSD license at http://PhysiCell.MathCancer.org and http://PhysiCell.sf.net.

Collagen Alignment as a Predictor of Recurrence after Ductal Carcinoma In Situ

Background: Collagen fibers surrounding breast ducts may influence breast cancer progression. Syndecan-1 interacts with constituents in the extracellular matrix, including collagen fibers, and may contribute to cancer cell migration. Thus, the orientation of collagen fibers surrounding ductal carcinoma in situ (DCIS) lesions and stromal syndecan-1 expression may predict recurrence.Methods: We evaluated collagen fiber alignment and syndecan-1 expression in 227 women diagnosed with DCIS in 1995 to 2006 followed through 2014 (median, 14.5 years; range, 0.7-17.6). Stromal collagen alignment was evaluated from diagnostic tissue slides using second harmonic generation microscopy and fiber analysis software. Univariate analysis was conducted using χ2 tests and ANOVA. The association between collagen alignment z-scores, syndecan-1 staining intensity, and time to recurrence was evaluated using HRs and 95% confidence intervals (CIs).Results: Greater fiber angles surrounding DCIS lesions, but not syndecan-1 staining intensity, were related to positive HER2 (P = 0.002) status, comedo necrosis (P = 0.03), and negative estrogen receptor (P = 0.002) and progesterone receptor (P = 0.02) status. Fiber angle distributions surrounding lesions included more angles closer to 90 degrees than normal ducts (P = 0.06). Collagen alignment z-scores for DCIS lesions were positively related to recurrence (HR = 1.25; 95% CI, 0.84-1.87 for an interquartile range increase in average fiber angles).Conclusions: Although collagen alignment and stromal syndecan-1 expression did not predict recurrence, collagen fibers perpendicular to the duct perimeter were more frequent in DCIS lesions with features typical of poor prognosis.Impact: Follow-up studies are warranted to examine whether additional features of the collagen matrix may more strongly predict patient outcomes. Cancer Epidemiol Biomarkers Prev; 27(2); 138-45. ©2017 AACR.

Profiling differential microRNA expression between in situ, infiltrative and lympho-vascular space invasive breast cancer: a pilot study

Ductal carcinoma in situ (DCIS), invasive breast cancer (IBC) and lympho-vascular invasion (LVI) represent distinct stages in breast cancer progression with different clinical implications. Altered microRNA (miRNA) expression may play a role in mediating the progression of DCIS to IBC and LVI. The aim of this pilot study was to investigate whether differential miRNA expression could play a role in breast cancer progression. Cancer cells from DCIS, IBC and LVI were microdissected from formalin fixed paraffin embedded (FFPE) tissue of five breast cancer samples. MiRNA profiling of extracted RNA was performed using the TaqMan^® Array Human MicroRNA Cards A and B v3.0. Candidate miRNAs and gene targets were validated by qPCR. 3D culture of MCF10A, MCF10DCIS.com and T47D cells were used as models for normal, DCIS and IBC. Immunohistochemistry of candidate genes was performed on FFPE 3D cell cultures as well as on tissue microarray which included cores of DCIS and IBC samples. MiR-150, miR-126 and miR-155 were found to be more highly expressed in IBC and LVI compared to DCIS. Gene targets of these miRNAs, RhoA, PEG10 and MYB, were found to be more highly expressed in DCIS compared to IBC by qPCR and in MCF10A and MCF10DCIS.com cells compared to T47D cells by immunohistochemistry. There was no difference in intensity of staining of RhoA by immunohistochemistry in DCIS versus IBC samples on tissue microarray. In this pilot study, we found evidence to support a potential role for variation in miRNA levels in the transition from DCIS to IBC.

MicroRNA-193a inhibits breast cancer proliferation and metastasis by downregulating WT1

In many cancers, microRNA-193a (miR-193a) is a suppressor miRNA, but its underlying anti-oncogenic activity in breast cancer is not known. In this study, we found decreased miR-193a (specifically, miR-193a-5p) expression not only in breast cancer cell lines but also in breast cancer tissues as compared with the adjacent non-tumor tissues. Ectopic miR-193a overexpression inhibited the proliferation, colony formation, migration, and invasion of MDA-MB-231 and BT549 cells. miR-193a reduced Wilms’ tumor 1 (WT1) expression and repressed luciferase reporter activity by binding WT1 coding region sequences; mutation of the predicted miR-193a binding site abolished this effect. miR-193a and WT1 expression were significantly inversely correlated in breast cancer tissues. Importantly, the anti-cancer activity induced by miR-193a was partially reversed by WT1 overexpression, indicating an important role for WT1 in such activity related to miR-193a. Our results reveal that miR-193a-WT1 interaction plays an important role in breast cancer metastasis, and suggest that restoring miR-193a expression is a therapeutic strategy in breast cancer.

Pilot study demonstrating metabolic and anti-proliferative effects of in vivo anti-oxidant supplementation with N-Acetylcysteine in Breast Cancer

BACKGROUND

High oxidative stress as defined by hydroxyl and peroxyl activity is often found in the stroma of human breast cancers. Oxidative stress induces stromal catabolism, which promotes cancer aggressiveness. Stromal cells exposed to oxidative stress release catabolites such as lactate, which are up-taken by cancer cells to support mitochondrial oxidative phosphorylation. The transfer of catabolites between stromal and cancer cells leads to metabolic heterogeneity between these cells and increased cancer cell proliferation and reduced apoptosis in preclinical models. N-Acetylcysteine (NAC) is an antioxidant that reduces oxidative stress and reverses stromal catabolism and stromal-carcinoma cell metabolic heterogeneity, resulting in reduced proliferation and increased apoptosis of cancer cells in experimental models of breast cancer. The purpose of this clinical trial was to determine if NAC could reduce markers of stromal-cancer metabolic heterogeneity and markers of cancer cell aggressiveness in human breast cancer.

METHODS

Subjects with newly diagnosed stage 0 and I breast cancer who were not going to receive neoadjuvant therapy prior to surgical resection were treated with NAC before definitive surgery to assess intra-tumoral metabolic markers. NAC was administered once a week intravenously at a dose of 150 mg/kg and 600 mg twice daily orally on the days not receiving intravenous NAC. Histochemistry for the stromal metabolic markers monocarboxylate transporter 4 (MCT4) and caveolin-1 (CAV1) and the Ki67 proliferation assay and TUNEL apoptosis assay in carcinoma cells were performed in pre- and post-NAC specimens.

RESULTS

The range of days on NAC was 14-27 and the mean was 19 days. Post-treatment biopsies showed significant decrease in stromal MCT4 and reduced Ki67 in carcinoma cells. NAC did not significantly change stromal CAV1 and carcinoma TUNEL staining. NAC was well tolerated.

CONCLUSIONS

NAC as a single agent reduces MCT4 stromal expression, which is a marker of glycolysis in breast cancer with reduced carcinoma cell proliferation. This study suggests that modulating metabolism in the tumor microenvironment has the potential to impact breast cancer proliferation.

Tumor-induced Stromal STAT1 Accelerates Breast Cancer via Deregulating Tissue Homeostasis

The tumor microenvironment (TME), the dynamic tissue space in which the tumor exists, plays a significant role in tumor initiation, and is a key contributor in cancer progression; however, little is known about tumor-induced changes in the adjacent tissue stroma. Herein, tumor-induced changes in the TME were explored at the morphologic and molecular level to further understand cancer progression. Tumor-adjacent mammary glands (TAG) displayed altered branching morphology, expansion of myofibroblasts, and increased mammosphere formation, broadly suggesting a tumor-induced field effect. FACS analysis of TAGs demonstrated an increased number of Lin^-CD24⁺/CD49⁺ enriched mammary gland stem cells (MaSC), suggesting deregulated tissue homeostasis in TAGs. Comparative transcriptome analysis of TAGs and contralateral control glands coupled with meta-analysis on differentially expressed genes with two breast cancer stromal patient microarray datasets identified shared upregulation of STAT1. Knockdown of STAT1 in cancer-associated fibroblast (CAF) cocultured with human breast cancer cells altered cancer cell proliferation, indicating a role for STAT1 as a stromal contributor of tumorigenesis. Furthermore, depletion of STAT1 in CAFs significantly reduced periductal reactive fibrosis and delayed early breast cancer progression in vivo Finally, cotreatment with fludarabine, a FDA-approved STAT1 activation inhibitor and DNA synthesis inhibitor, in combination with doxorubicin, showed enhanced therapeutic efficacy in treating mouse mammary gland tumors. Taken together, these results demonstrate that stromal STAT1 expression promotes tumor progression and is a potential therapeutic target for breast cancer.Implications: Tumors induce stromal STAT1-dependent cytokine secretion that promotes tumor cell proliferation and can be targeted using clinically-approved inhibitors of STAT1. Mol Cancer Res; 15(5); 585-97. ©2017 AACR.

Characterizing the immune microenvironment in high-risk ductal carcinoma in situ of the breast

PURPOSE

The recent increase in the incidence of ductal carcinoma in situ (DCIS) has sparked debate over the classification and treatment of this disease. Although DCIS is considered a precursor lesion to invasive breast cancer, some DCIS may have more or less risk than is realized. In this study, we characterized the immune microenvironment in DCIS to determine if immune infiltrates are predictive of recurrence.

METHODS

Fifty-two cases of high-grade DCIS (HG-DCIS), enriched for large lesions and a history of recurrence, were age matched with 65 cases of non-high-grade DCIS (nHG-DCIS). Immune infiltrates were characterized by single- or dual-color staining of FFPE sections for the following antigens: CD4, CD8, CD20, FoxP3, CD68, CD115, Mac387, MRC1, HLA-DR, and PCNA. Nuance multispectral imaging software was used for image acquisition. Protocols for automated image analysis were developed using CellProfiler. Immune cell populations associated with risk of recurrence were identified using classification and regression tree analysis.

RESULTS

HG-DCIS had significantly higher percentages of FoxP3⁺ cells, CD68⁺ and CD68⁺PCNA⁺ macrophages, HLA-DR⁺ cells, CD4⁺ T cells, CD20⁺ B cells, and total tumor infiltrating lymphocytes compared to nHG-DCIS. A classification tree, generated from 16 immune cell populations and 8 clinical parameters, identified three immune cell populations associated with risk of recurrence: CD8⁺HLADR⁺ T cells, CD8⁺HLADR^- T cells, and CD115⁺ cells.

CONCLUSION

These findings suggest that the tumor immune microenvironment is an important factor in identifying DCIS cases with the highest risk for recurrence and that manipulating the immune microenvironment may be an efficacious strategy to alter or prevent disease progression.

Pigmented lesion of the nipple - a clinicopathological challenge

Differential diagnoses of pigmented lesions of the nipple include melanocytic nevus, melanosis of the nipple, seborrheic keratosis, pigmented basal cell carcinoma, melanoma and Paget disease. The histologic exam with appropriate immunohistochemistry is a fundamental tool to achieve a correct diagnosis. We present a patient with a pigmented lesion of her right nipple revealing mammary Paget disease and elucidate diagnostic obstacles and prognostic importance of early breast cancer detection.