Defining the biological basis of radiomic phenotypes in lung cancer

Medical imaging can visualize characteristics of human cancer noninvasively. Radiomics is an emerging field that translates these medical images into quantitative data to enable phenotypic profiling of tumors. While radiomics has been associated with several clinical endpoints, the complex relationships of radiomics, clinical factors, and tumor biology are largely unknown. To this end, we analyzed two independent cohorts of respectively 262 North American and 89 European patients with lung cancer, and consistently identified previously undescribed associations between radiomic imaging features, molecular pathways, and clinical factors. In particular, we found a relationship between imaging features, immune response, inflammation, and survival, which was further validated by immunohistochemical staining. Moreover, a number of imaging features showed predictive value for specific pathways; for example, intra-tumor heterogeneity features predicted activity of RNA polymerase transcription (AUC = 0.62, p=0.03) and intensity dispersion was predictive of the autodegration pathway of a ubiquitin ligase (AUC = 0.69, p<10^-4). Finally, we observed that prognostic biomarkers performed highest when combining radiomic, genetic, and clinical information (CI = 0.73, p<10^-9) indicating complementary value of these data. In conclusion, we demonstrate that radiomic approaches permit noninvasive assessment of both molecular and clinical characteristics of tumors, and therefore have the potential to advance clinical decision-making by systematically analyzing standard-of-care medical images.

DOI:http://dx.doi.org/10.7554/eLife.23421.001

Medical imaging covers a wide range of techniques that are used to look inside the body, including X-rays, MRI scans and ultrasound. A process called radiomics uses computer algorithms to process the data collected by these techniques to identify and precisely measure a large number of features that would not otherwise be quantifiable by human experts. By doing so, radiomics can automatically measure the radiographic characteristics of a tumor. For example, radiomics can establish the size, shape and texture of a tumor to help to diagnose cancer and guide its treatment.

Research has suggested that radiomics can predict certain clinical characteristics of cancer, such as how far through the body the cancer has spread, how likely it is to respond to treatment, and how likely a patient is to survive. However, these radiomic characteristics have not yet been precisely linked to the biological processes that drive how cancer develops and spreads.

Cancers develop as a result of genetic changes that activate “molecular pathways” in the cells and trigger processes such as cell division and inflammation. To work out exactly which changes are behind a particular tumor, a sample of the tumor from biopsy or surgery is analyzed using genomics techniques. Linking radiomics features to the molecular processes active in a tumor can generate further information that can complement the molecular data. Images are routinely collected on all cancer patients yet molecular data is not. Hence, in some cases, the images can be used to infer the molecular underpinnings of cancer in individual patients.

Grossmann et al. have now analyzed radiomic, genomic and clinical data collected from approximately 350 patients with lung cancer. The analysis revealed links between biological processes normally detected by genomics – in particular, inflammatory responses – and radiomics features. Furthermore, these features could also be associated with clinical characteristics, such as tumor type and patient survival rates. These results were further validated by using a technique called immunohistochemical staining on tumor tissue obtained by surgery.

Further investigation revealed that certain radiomics features can predict the state of molecular pathways that are key to cancer development (such as the inflammatory response). Furthermore, Grossmann et al. found that combining data from radiomics, genomics and clinical parameters predicts how the cancer will progress better than any of these parameters can predict on their own. These results demonstrate the complementary value of radiomic data to genomic and clinical data.

There are many different algorithms that can be used to process images for radiomics. Before radiomics can be used clinically to assess the biological processes underlying the tumors of patients, a specific algorithm needs to be decided upon and then tested in prospective clinical trials.

DOI:http://dx.doi.org/10.7554/eLife.23421.002

Image Analysis of the Tumor Microenvironment

In the field of pathology it is clear that molecular genomics and digital imaging represent two promising future directions, and both are as relevant to the tumor microenvironment as they are to the tumor itself (Beck AH et al. Sci Transl Med 3(108):108ra113-08ra113, 2011). Digital imaging, or whole slide imaging (WSI), of glass histology slides facilitates a number of value-added competencies which were not previously possible with the traditional analog review of these slides under a microscope by a pathologist. As an important tool for investigational research, digital pathology can leverage the quantification and reproducibility offered by image analysis to add value to the pathology field. This chapter will focus on the application of image analysis to investigate the tumor microenvironment and how quantitative investigation can provide deeper insight into our understanding of the tumor to tumor microenvironment relationship.

Defining Cancer Subpopulations by Adaptive Strategies Rather Than Molecular Properties Provides Novel Insights into Intratumoral Evolution

Ongoing intratumoral evolution is apparent in molecular variations among cancer cells from different regions of the same tumor, but genetic data alone provide little insight into environmental selection forces and cellular phenotypic adaptations that govern the underlying Darwinian dynamics. In three spontaneous murine cancers (prostate cancers in TRAMP and PTEN mice, pancreatic cancer in KPC mice), we identified two subpopulations with distinct niche construction adaptive strategies that remained stable in culture: (i) invasive cells that produce an acidic environment via upregulated aerobic glycolysis; and (ii) noninvasive cells that were angiogenic and metabolically near-normal. Darwinian interactions of these subpopulations were investigated in TRAMP prostate cancers. Computer simulations demonstrated invasive, acid-producing (C2) cells maintain a fitness advantage over noninvasive, angiogenic (C3) cells by promoting invasion and reducing efficacy of immune response. Immunohistochemical analysis of untreated tumors confirmed that C2 cells were invariably more abundant than C3 cells. However, the C2 adaptive strategy phenotype incurred a significant cost due to inefficient energy production (i.e., aerobic glycolysis) and depletion of resources for adaptations to an acidic environment. Mathematical model simulations predicted that small perturbations of the microenvironmental extracellular pH (pHe) could invert the cost/benefit ratio of the C2 strategy and select for C3 cells. In vivo, 200 mmol/L NaHCO3 added to the drinking water of 4-week-old TRAMP mice increased the intraprostatic pHe by 0.2 units and promoted proliferation of noninvasive C3 cells, which remained confined within the ducts so that primary cancer did not develop. A 0.2 pHe increase in established tumors increased the fraction of C3 cells and signficantly diminished growth of primary and metastatic tumors. In an experimental tumor construct, MCF7 and MDA-MB-231 breast cancer cells were coinjected into the mammary fat pad of SCID mice. C2-like MDA-MB-231 cells dominated in untreated animals, but C3-like MCF7 cells were selected and tumor growth slowed when intratumoral pHe was increased. Overall, our data support the use of mathematical modeling of intratumoral Darwinian interactions of environmental selection forces and cancer cell adaptive strategies. These models allow the tumor to be steered into a less invasive pathway through the application of small but selective biological force. Cancer Res; 77(9); 2242-54. ©2017 AACR.

Myoepithelial carcinoma with RB1 mutation: remarkable chemosensitivity to carcinoma of unknown origin therapy

Background

Myoepithelial carcinoma of soft tissue is a rare, malignant neoplasm that is morphologically and immunophenotypically similar to its counterpart in salivary gland. It demonstrates myoepithelial differentiation, possessing both epithelial and myogenic characteristics. Thought to be chemotherapy insensitive, the optimal treatment regimen of this tumor has yet to be established and only a select few cases in the literature discuss treatment efficacy in detail.

Case presentation

Here we present a case of a young adult with metastatic myoepithelial carcinoma with an initial excellent response to systemic therapy utilizing carboplatin and paclitaxel with continued complete response after 3 years. The patient also underwent complete surgical excision and received adjuvant radiation to the primary site of disease. Exome sequencing revealed an inactivating mutation in RB1 which we believe to be the first such mutation to be reported in this cancer type.

Conclusions

Given increasing evidence suggesting RB1 loss is associated with responsiveness to conventional chemotherapies, particularly platinum-based regimens, we hypothesize that this genetic feature predisposed chemosensitivity in our patient’s tumor.

Educational Value of Digital Whole Slides Accompanying Published Online Pathology Journal Articles: A Multi-Institutional Study

CONTEXT

-Despite great interest in using whole slide imaging (WSI) in pathology practice and education, few pathology journals have published WSI pertinent to articles within their pages or as supplemental materials.

OBJECTIVE

-To evaluate whether there is measurable added educational value of including WSI in publications.

DESIGN

-Thirty-seven participants, 16 (43.3%), 15 (40.5%), and 6 (16.2%) junior pathology residents (postgraduate year 1-2), senior pathology residents (postgraduate year 3-4), and board-certified pathologists, respectively, read a sequence of 10 journal articles on a wide range of pathology topics. A randomized subgroup also reviewed the WSI published with the articles. Both groups completed a survey tool assessing recall of text-based content and of image-based material pertinent to the diseases but not present in the fixed published images.

RESULTS

-The group examining WSI had higher performance scores in 72% of image-based questions (36 of 50 questions) as compared with the non-WSI group. As an internal study control, the WSI group had higher performance scores in only 40% of text-based questions (6 of 15 questions). The WSI group had significantly better performance than the non-WSI group for image-based questions compared with text-based questions (P < .05, Fisher exact test).

CONCLUSION

-Our study provides supporting evidence that WSI offers enhanced value to the learner beyond the text and fixed images selected by the author. We strongly encourage more journals to incorporate WSI into their publications.

Practical Issues for Retroperitoneal Sarcoma

Background

Retroperitoneal sarcoma is rare. Using initial specimens on biopsy, a definitive diagnosis of histological subtypes is ideal but not always achievable.

Methods

A retrospective institutional review was performed for all cases of adult retroperitoneal sarcoma from 1996 to 2015. A review of the literature was also performed related to the distribution of retroperitoneal sarcoma subtypes. A meta-analysis was performed.

Results

Liposarcoma is the most common subtype (45%), followed by leiomyosarcoma (21%), not otherwise specified (8%), and undifferentiated pleomorphic sarcoma (6%) by literature review. Data from Moffitt Cancer Center demonstrate the same general distribution for subtypes of retroperitoneal sarcoma. A pathology-based algorithm for the diagnosis of retroperitoneal sarcoma is illustrated, and common pitfalls in the pathology of retroperitoneal sarcoma are discussed.

Conclusions

An informative diagnosis of retroperitoneal sarcoma via specimens on biopsy is achievable and meaningful to guide effective therapy. A practical and multidisciplinary algorithm focused on the histopathology is helpful for the management of retroperitoneal sarcoma.

Implications of staged reconstruction and adjuvant brachytherapy in the treatment of recurrent soft tissue sarcoma

PURPOSE

Prior studies illustrated a reduction in wound complications with the use of staged reconstruction (SR) and negative pressure wound therapy when treating soft tissue sarcoma (STS) with surgical resection followed by high-dose-rate adjuvant brachytherapy. The purpose of this study is to compare the outcomes of SR and immediate reconstruction (IR) brachytherapy in recurrent STS.

METHODS AND MATERIALS

A retrospective review of 40 patients with recurrent STS of the local extremity and trunk treated with resection followed by adjuvant brachytherapy alone. Margin status was defined as positive (SM(+)) if there was microscopic involvement (R1) or ≤1 mm margin and negative (SM(-)) if >1 mm margin was obtained. SR and IR were compared regarding toxicity, local control, and limb preservation.

RESULTS

Median followup was 27 months. When comparing the SR (n = 22) and IR (n = 18) cohorts, there was a significantly lower final SM(+) rate in SR (32% vs. 83%, p < 0.01). A 2-year local control benefit seen with SR (80% vs. 34%; p = 0.012) and a final SM(-) (81% vs. 39%; p = 0.023). SR was associated with less toxicity on multivariate analysis, including a 90% decrease in persistent edema, an 80% decrease in wound dehiscence, and a 94% decrease in nonhealing wounds, when compared to IR. Ten of 31 (32%) extremity cases required eventual amputation from either chronic wound complications (n = 4) or local recurrence (n = 6). SR predicted for a benefit in 2-year limb preservation (88% vs. 50%; p = 0.008).

CONCLUSION

In our series, the treatment with SR brachytherapy resulted in less morbidity and an improved final SM(-) rate. This technique translated to an improvement in both local control and limb preservation of recurrent STS.

Darwinian Dynamics of Intratumoral Heterogeneity: Not Solely Random Mutations but Also Variable Environmental Selection Forces

Spatial heterogeneity in tumors is generally thought to result from branching clonal evolution driven by random mutations that accumulate during tumor development. However, this concept rests on the implicit assumption that cancer cells never evolve to a fitness maximum because they can always acquire mutations that increase proliferative capacity. In this study, we investigated the validity of this assumption. Using evolutionary game theory, we demonstrate that local cancer cell populations will rapidly converge to the fittest phenotype given a stable environment. In such settings, cellular spatial heterogeneity in a tumor will be largely governed by regional variations in environmental conditions, for example, alterations in blood flow. Model simulations specifically predict a common spatial pattern in which cancer cells at the tumor-host interface exhibit invasion-promoting, rapidly proliferating phenotypic properties, whereas cells in the tumor core maximize their population density by promoting supportive tissue infrastructures, for example, to promote angiogenesis. We tested model predictions through detailed quantitative image analysis of phenotypic spatial distribution in histologic sections of 10 patients with stage 2 invasive breast cancers. CAIX, GLUT1, and Ki67 were upregulated in the tumor edge, consistent with an acid-producing invasive, proliferative phenotype. Cells in the tumor core were 20% denser than the edge, exhibiting upregulation of CAXII, HIF-1α, and cleaved caspase-3, consistent with a more static and less proliferative phenotype. Similarly, vascularity was consistently lower in the tumor center compared with the tumor edges. Lymphocytic immune responses to tumor antigens also trended to higher level in the tumor edge, although this effect did not reach statistical significance. Like invasive species in nature, cancer cells at the leading edge of the tumor possess a different phenotype from cells in the tumor core. Our results suggest that at least some of the molecular heterogeneity in cancer cells in tumors is governed by predictable regional variations in environmental selection forces, arguing against the assumption that cancer cells can evolve toward a local fitness maximum by random accumulation of mutations. Cancer Res; 76(11); 3136-44. ©2016 AACR.

Molecular Pathology of Soft-Tissue Neoplasms and Its Role in Clinical Practice

BACKGROUND

Soft-tissue neoplasms embody a histologically diverse group of mesenchymal tumors. Oftentimes the histopathological diagnosis of soft-tissue tumors is challenging due to overlapping pathological features.

METHODS

We reviewed the current and most importantly known recurrent or tumor-specific genetic abnormalities involving soft-tissue tumors, focusing on how they are useful in working up differential diagnoses and the relevance of potentially targeted therapies.

RESULTS

Molecular diagnostic tools have shown great advantage as an aid in the differentiation between different soft-tissue tumor entities, providing a potential avenue in the identification of novel therapeutic targets. Gastrointestinal stromal tumor is a well-known example of a soft-tissue tumor with a successful, molecularly driven treatment with response rates of more than 80% in stable disease and partial remission. Classifying soft-tissue neoplasms by their molecular genetic pathology has been considered as molecular testing becomes more integrated into various diagnostic and prognostic algorithms.

CONCLUSIONS

Molecular pathology provides a unique opportunity for pathologists to play a crucial role in the multidisciplinary care of patients with sarcoma. These opportunities include but are not limited to the appropriate triage of tissue for molecular testing and the integration of molecular testing results, with histological and immunohistochemical findings providing actionable information for the diagnosis, prognosis, and choice of therapeutic modality.

Overexpression of Vascular Endothelial Growth Factor A in Invasive Micropapillary Colorectal Carcinoma

BACKGROUND

Invasive micropapillary carcinoma (IMPC) is a rare variant of colorectal cancer with an adverse prognosis. "Retraction artifact" around tumor cells is a feature of IMPC. The aim of this study was to assess the nature of the retractions around the tumor cells and to describe the histopathological features of a group of 18 cases of IMPC.

METHODS

A pathology review of 128 consecutive colorectal cancers identified 18 cases of histologically proven IMPC using 5% of the total tumor volume comprised of a micropapillary component as the diagnostic criterion. Immunostains for D2-40, CD31, CD34, vascular endothelial growth factor A (VEGF-A), and mucin 1 (MUC-1) were performed using the avidin-biotin complex method.

RESULTS

Cases of IMPC were characterized by pseudomicropapillae surrounded by lacunar-like clear spaces. These structures exhibited the inside-out growth pattern as highlighted by MUC-1 staining. The lining of the lacunar spaces was immunoreactive to CD31 but not CD34 or D2-40, indicating that they are neovascular structures. Furthermore, the tumor cells strongly and diffusely expressed VEGF-A.

CONCLUSIONS

The strong coexpression of VEGF-A and CD31 suggests a prominent role of neoangiogenesis in these tumors.

Clinical Characteristics and Outcomes for Solitary Fibrous Tumor (SFT): A Single Center Experience

Solitary fibrous tumor (SFT) is a mesenchymal neoplasm of fibrous origin. The 2013 WHO classification of soft tissue tumors defines malignant forms as hypercellular, mitotically active (>4 mitosis/10 high-power fields), with cytological atypia, tumor necrosis, and/or infiltrative margins. With an IRB-approved protocol, we investigated patient records and clinicopathologic data from our Sarcoma Database to describe the clinical characteristics of both benign and malignant SFT. All pathology specimens were reviewed by two pathologists. Descriptive statistics and univariate/multivariate survival analysis were performed. Patient records and Social Security Death Index were used to evaluate vital status. Of 82 patients, 47 (57%) were women and 73 (89%) were Caucasian. Median age was 62 years (range, 20 to 89). Thirty-two (39%) patients succumbed to the disease. Primary tumor site was lung/pleura in 28 (34%), abdomen/pelvis in 23 (28%), extremity in 13 (16%), and head/neck in 9 (11%) patients. Pathology was described as benign in 42 (51%) and malignant in 40 (49%) patients. Compared to benign SFT, malignant histology is associated with larger tumor size, higher mitotic counts, metastatic disease at diagnosis, and greater use of chemotherapy and radiation therapy. Gender, age, and tumor site were not significantly different between benign and malignant subtypes. By univariate analysis, only benign vs. malignant variant and complete resection positively impacted overall survival (P = 0.02 and P<0.0001, respectively). In the multivariable analysis of overall survival, receiving chemotherapy or not receiving surgery were two variables significantly associated with higher failure rate in overall survival: patients with chemotherapy vs. no chemotherapy (P = 0.003, HR = 4.55, with 95% CI: 1.68–12.34) and patients without surgery vs. with surgery (P = 0.005, HR = 25.49, with 95% CI: 2.62–247.57). Clear survival differences exist between benign and malignant SFT. While surgery appears to be the best treatment option for benign and malignant SFT, better systemic therapies are needed to improve outcomes of patients with metastatic, malignant SFT.

Diagnostic assessment of osteosarcoma chemoresistance based on Virtual Clinical Trials

Osteosarcoma is the most common primary bone tumor in pediatric and young adult patients. Successful treatment of osteosarcomas requires a combination of surgical resection and systemic chemotherapy, both neoadjuvant (prior to surgery) and adjuvant (after surgery). The degree of necrosis following neoadjuvant chemotherapy correlates with the subsequent probability of disease-free survival. Tumors with less than 10% of viable cells after treatment represent patients with a more favorable prognosis. However, being able to predict early, such as at the time of the pre-treatment tumor biopsy, how the patient will respond to the standard chemotherapy would provide an opportunity for more personalized patient care. Patients with unfavorable predictions could be studied in a protocol, rather than a standard setting, towards improving therapeutic success. The onset of necrotic cells in osteosarcomas treated with chemotherapeutic agents is a measure of tumor sensitivity to the drugs. We hypothesize that the remaining viable cells, i.e., cells that have not responded to the treatment, are chemoresistant, and that the pathological characteristics of these chemoresistant tumor cells within the osteosarcoma pre-treatment biopsy can predict tumor response to the standard-of-care chemotherapeutic treatment. This hypothesis can be tested by comparing patient histopathology samples before, as well as after treatment to identify both morphological and immunochemical cellular features that are characteristic of chemoresistant cells, i.e., cells that survived treatment. Consequently, using computational simulations of dynamic changes in tumor pathology under the simulated standard of care chemotherapeutic treatment, one can couple the pre- and post-treatment morphological and spatial patterns of chemoresistant cells, and correlate them with patient clinical diagnoses. This procedure, that we named 'Virtual Clinical Trials', can serve as a potential predictive biomarker providing a novel value-added decision support tool for oncologists.

Akt and Hippo Pathways in Ewing's Sarcoma Tumors and Their Prognostic Significance

Background: Ewing's sarcoma tumor is an aggressive malignancy of bone and soft tissue in children and young adults. Despite advances in modern therapy, metastasis occurs and results in high mortality. Intracellular molecules Yap, Akt, mTOR, and Erk are signaling pathway members that regulate the proliferation of tumor cells.

Objective and Methods: We studied the immunohistochemical expression of these proteins in 36 tumor samples from adult and pediatric patients with Ewing's sarcoma tumors. Patients' age, sex, tumor site, tumor size, clinical stage and survival (overall and disease-free survival) were collected. Tissue microarrays slides were stained with antibodies against Yap, Akt, mTOR, and Erk proteins.

Results: Tumors exhibited variable expression of Yap, Akt, mTOR, and Erk (from negative, low to high), with high levels of expression present in 31%, 53%, 77% and 0% respectively. Immunohistochemical expression of Akt was associated with worse overall and disease-free survival (p<0.05). The other biomarkers did not demonstrate any difference in survival between low versus high expression.

Conclusion: Although Yap, Akt, mTOR, and Erk protein are all expressed in Ewing's sarcoma by immunohistochemistry, only Akt expression is associated with worse prognosis. Larger studies are needed to verify these results and plan targeted therapy, particularly against Akt.

Primary Bone Tumors: Epidemiologic Comparison of 9200 Patients Treated at Beijing Ji Shui Tan Hospital, Beijing, China, With 10 165 Patients at Mayo Clinic, Rochester, Minnesota

Context

Although primary bone tumors are extremely rare, the literature suggests that there are variations in the epidemiologic characteristics in different populations. The most frequently cited epidemiologic characteristics of primary bone tumors are derived from a large US series (Mayo Clinic), with no comparable study thus far performed in China.

Objective

To identify any potential epidemiologic differences between Chinese patients and a US series of patients.

Design

We performed a comparison study between 9200 patients treated at Beijing Ji Shui Tan Hospital (JST) and 10 165 patients treated at Mayo Clinic (MC), Rochester Minnesota. Detailed epidemiologic features were analyzed.

Results

We found that giant cell tumor and osteosarcoma have significantly higher incidences in the JST than the MC patients (P &lt; .001). However, JST patients had a significantly lower incidence of Ewing sarcoma, chordoma, fibrosarcoma, myeloma, and malignant lymphoma (P &lt; .001). For most benign and malignant bone tumors, the Chinese cohort had a more distinct male predominance than the US cohort. Malignant bone tumors had a monomodal age distribution in the JST patient group, with a bimodal age distribution in the MC cohort. Also, there were was a predilection for tumors of the femur and tibia among the JST patients (P &lt; .001).

Conclusions

Our data confirm that epidemiologic variations of primary bone tumors exist in different populations. Factors that may contribute to these observed differences are proposed and discussed.

Gastrointestinal stromal tumors, version 2.2014

Gastrointestinal stromal tumors (GIST) are the most common soft tissue sarcoma of the gastrointestinal tract, resulting most commonly from KIT or platelet-derived growth factor receptor α (PDGFRα)-activating mutations. These NCCN Guideline Insights highlight the important updates to the NCCN Guidelines for Soft Tissue Sarcoma specific to the management of patients with GIST experiencing disease progression while on imatinib and/or sunitinib.

CYP3A isoforms in Ewing's sarcoma tumours: an immunohistochemical study with clinical correlation

Ewing's sarcoma is an aggressive malignancy of bone and soft tissue with high incidence of metastasis and resistance to chemotherapy. Cytochrome P450 (CYP) monooxygenases are a family of enzymes that are involved in the metabolism of exogenous and endogenous compounds, including anti-cancer drugs, and have been implicated in the aggressive behaviour of various malignancies. Tumour samples and clinical information including age, sex, tumour site, tumour size, clinical stage and survival were collected from 36 adult and paediatric patients with Ewing's sarcoma family tumours. Tissue microarrays slides were processed for immunohistochemical labelling for CYP3A4, CYP3A5 and CYP3A7 using liver sections as positive control. The intensity of staining was scored as negative, low or high expression and was analysed statistically for any association with patients' clinical information. Four cases were later excluded due to inadequate viable tissue. CYP3A4 staining was present in 26 (81%) cases with high expression noted in 13 (40%) of 32 cases. High expression was significantly associated with distant metastases (P < 0.05). CYP3A5 and CYP3A7 were expressed in 5 and 13 cases respectively (15.6%, 40.6%). There was no association between the expression of CYP3A isoforms and age, sex, tumour size, or location (pelvic or extra-pelvic). None of the biomarkers showed any correlation with overall or disease-free survival. In conclusion, expression of CYP3A isoforms is noted in Ewing's sarcoma tumours and high CYP3A4 expression may be associated with metastasis. Additional studies are needed to further investigate the role of CYP3A4 in the prognosis of these tumours.

Long non-coding RNAs (LncRNA) regulated by transforming growth factor (TGF) β: LncRNA-hit-mediated TGFβ-induced epithelial to mesenchymal transition in mammary epithelia

Long noncoding RNAs (lncRNAs) are emerging as key regulators in various biological processes. Epithelial-to-mesenchymal transition (EMT) is a developmental process hijacked by tumor cells to depart from the primary tumor site, invade surrounding tissue, and establish distant metastases. Transforming growth factor β (TGFβ) signaling has been shown to be a major inducer of EMT and to facilitate breast cancer metastasis. However, the role of lncRNAs in this process remains largely unknown. Here we report a genome-wide lncRNA profile in mouse mammary epithelial NMuMG cells upon TGFβ induction of EMT. Among 10,802 lncRNAs profiled, over 600 were up-regulated and down-regulated during the EMT, respectively. Furthermore, we identify that lncRNA-HIT (HOXA transcript induced by TGFβ) mediates TGFβ function, i.e. depletion of lncRNA-HIT inhibits TGFβ-induced migration, invasion, and EMT in NMuMG. LncRNA-HIT is also significantly elevated in the highly metastatic 4T1 cells. Knockdown of lncRNA-HIT in 4T1 results in decrease of cell migration, invasion, tumor growth, and metastasis. E-cadherin was identified as a major target of lncRNA-HIT. Moreover, lncRNA-HIT is conserved in humans and elevated expression associates with more invasive human primary breast carcinoma. Collectively, these data suggest that a subset of lncRNAs such as lncRNA-HIT play a significant role in regulation of EMT and breast cancer invasion and metastasis, and could be potential therapeutic targets in breast cancers.

Beta-catenin expression patterns in matched pre- and post-neoadjuvant chemotherapy-resistant breast cancer

BACKGROUND

β-catenin is a critical component of the cadherin cell-to-cell adhesion pathway and a key participant in the Wnt signaling pathway. Activation of β-catenin signaling in the Wnt pathway is a known contributor to tumor cancer progression and metastasis and may result in resistance to chemotherapeutic agents. The aim of this study is to evaluate the patterns of expression of β-catenin in breast carcinoma cells before and after neoadjuvant chemotherapy. Discovery of the molecular mechanisms responsible for resistance to chemotherapy treatment could result in more effective therapy, and improve outcome and survival.

DESIGN

Twenty-nine matched pre-treatment and post-neoadjuvant chemotherapy breast carcinomas were subjected to immunohistochemical study using anti-β-catenin antibody. Normal staining was defined as crisp membrane staining in >90% tumor cells; aberrant expression was nuclear staining in >5% tumor cells.

RESULTS

Of the 29 included cases, five cases of invasive lobular carcinoma lacked β-catenin immunoreactivity pre- and post-treatment. Mildly reduced membranous staining was seen in two post-treatment samples. One case of triple-negative ductal carcinoma had reduced pre- and post-treatment staining. All other cases showed normal pre- and post-treatment β-catenin expression. No aberrant staining was identified.

CONCLUSION

In our study, there was no difference in the expression of β-catenin in pre- and post-neoadjuvant chemotherapy specimens. These results do not suggest that β-catenin plays a role in conferring neoadjuvant chemotherapy resistance.

Histopathological and immunophenotypical features of intestinal-type adenocarcinoma of the gallbladder and its precursors

BACKGROUND

Intestinal-type adenocarcinoma of the gallbladder is an unusual malignancy associated with low- and high-grade intraepithelial neoplasms. The literature on the clinicopathologic characteristics of the precursor lesions of gallbladder cancer is limited, due in part to the variability in its definition and terminology.

METHODS

Here we report one case of intestinal-type adenocarcinoma of the gallbladder with distinctive morphology and associated precursor lesions. All of the hematoxylin and eosin stained slides were reviewed. Immunostains were performed using the avidin-biotin complex method for CK20, CK7, CDX2, MUC1, MUC2, and MUC-5AC. We also reviewed the literature discussing the current terminology from the World Health Organization for these lesions.

RESULTS

A 70-year-old man presented with epigastric abdominal pain and bloating. Computed tomography demonstrated a large heterogeneous gallbladder mass. Macroscopically, the gallbladder was 7.5 x 5.5 x 4.5 cm with smooth serosa. The lumen was occupied by a 5.0 x 4.5 x 3.0 cm irregular friable exophytic mass. The remaining mucosa had a tan brown to pink color with granular/papillary excrescences of up to 0.7 cm in thickness. Histologically, the tubulopapillary adenoma was lined by pseudostratified columnar epithelium with low and extensive high-grade dysplasia. Goblet cell and cystic dilatation were present in some glands. Immunohistochemistry showed that the intestinal type was positive for CK20, CK7, and CDX2, focally positive for MUC1/2, and negative for MUC-5AC.

CONCLUSION

This case showed the complete spectrum of the progression of intestinal-type intracholecystic papillary-tubular neoplasms of the gallbladder.