Density Of Tertiary Lymphoid Structures Research Articles

Tertiary lymphoid structures predict the prognosis and immunotherapy response of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a malignant tumor of the biliary epithelium with a poor prognosis. The lack of biomarkers to predict therapeutic response and prognosis is one of the major challenges for CCA treatment. Tertiary lymphoid structures (TLS) provide a local and pivotal microenvironment for tumor immune responses. The prognostic value and clinical relevance of TLS in CCA remain unclear. We aimed to explore the characteristics and clinical significance of TLS in CCA. We investigated the prognostic value and clinical relevance of TLS in CCA using a surgery cohort containing 471 CCA patients (cohort 1) and an immunotherapy cohort containing 100 CCA patients (cohort 2). Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were used to evaluate the maturity of TLS. Multiplex IHC (mIHC) was employed to characterize the composition of TLS. Different maturity of TLS were observed in CCA tissue sections. Strong staining of the four-gene signature including PAX5, TCL1A, TNFRSF13C, and CD79A were found in TLS regions. A high density of intra-tumoral TLS (T-score high) were significantly correlated with longer overall survival (OS) both in CCA cohort 1 (p = 0.002) and cohort 2 (p = 0.01), whereas a high density of peri-tumoral TLS (P-score high) were associated with shorter OS in these two cohorts (p = 0.003 and p = 0.03, respectively). The established four-gene signature efficiently identified the TLS in CCA tissues. The abundance and spatial distribution of TLS were significantly correlated with the prognosis and immune checkpoint inhibitors (ICIs) immunotherapy response of CCA patients. The presence of intra-tumoral TLS are positive prognostic factors for CCA, which provide a theoretical basis for the future diagnosis and treatment of CCA.

Localization and density of tertiary lymphoid structures associate with molecular subtype and clinical outcome in colorectal cancer liver metastases

BackgroundTertiary lymphoid structures (TLSs) have been proposed to assess the prognosis of patients with cancer. Here, we investigated the prognostic value and relevant mechanisms of TLSs in colorectal cancer liver...

Post-transplant Malignancies Show Reduced T-cell Abundance and Tertiary Lymphoid Structures as Correlates of Impaired Cancer Immunosurveillance.

An increased risk to develop cancer is one of the most challenging negative side effects of long-term immunosuppression in organ transplant recipients and impaired cancer immunosurveillance is assumed as underlying mechanism. This study aims to elucidate transplant-related changes in the tumor immune microenvironment (TME) of cancer. Data from 123 organ transplant recipients (kidney, heart, lung, and liver) were compared with historic data from non-immunosuppressed patients. Digital image analysis of whole-section slides was used to assess abundance and spatial distribution of T cells and tertiary lymphoid structures (TLS) in the TME of 117 tumor samples. Expression of programmed cell death 1 ligand 1 (PD-L1) and human-leucocyte-antigen class I (HLA-I) was assessed on tissue microarrays. We found a remarkably reduced immune infiltrate in the center tumor (CT) regions as well as the invasive margins (IM) of post-transplant cancers. These differences were more pronounced in the IM than in the CT and larger for CD8+ T cells than for CD3+ T cells. The Immune-score integrating results from CT and IM was also lower in transplant recipients. Density of TLS was lower in cancer samples of transplant recipients. The fraction of samples with PD-L1 expression was higher in controls whereas decreased expression of HLA-I was more common in transplant recipients. Our study demonstrates the impact of immunosuppression on the TME and supports impaired cancer immunosurveillance as important cause of post-transplant cancer. Modern immunosuppressive protocols and cancer therapies should consider the distinct immune microenvironment of post-transplant malignancies.

Localization and Density of Tertiary Lymphoid Structures Associate with Molecular Subtype And Clinical Outcome in Colorectal Cancer Liver Metastases

Localization and Density of Tertiary Lymphoid Structures Associate with Molecular Subtype And Clinical Outcome in Colorectal Cancer Liver Metastases

Distribution and density of tertiary lymphoid structures predict clinical outcome in intrahepatic cholangiocarcinoma

The prognostic value and clinical relevance of tertiary lymphoid structures (TLSs) in intrahepatic cholangiocarcinoma (iCCA) remain unclear. Thus, we aimed to investigate the prognostic value and functional involvement of TLSs in iCCA. We retrospectively included 962 patients from 3 cancer centers across China. The TLSs at different anatomic subregions were quantified and correlated with overall survival (OS) by Cox regression and Kaplan-Meier analyses. Multiplex immunohistochemistry (mIHC) was applied to characterize the composition of TLSs in 39 iCCA samples. A quaternary TLS scoring system was established for the intra-tumor region (T score) and peri-tumor region (P score) respectively. T scores positively correlated with favorable prognosis (p <0.001), whereas a high P score signified worse survival (p <0.001). mIHC demonstrated that both T follicular helper and regulatory T cells were significantly increased in intra-tumoral TLSs compared to peri-tumoral counterparts (p <0.05), and regulatory T cell frequencies within intra-tumoral TLSs were positively associated with P score (p <0.05) rather than T score. Collectively, the combination of T and P scores stratified iCCAs into 4 immune classes with distinct prognoses (p <0.001) that differed in the abundance and distribution pattern of TLSs. Patients displaying an immune-active pattern had the lowest risk, with 5-year OS rates of 68.8%, whereas only 3.4% of patients with an immune-excluded pattern survived at 5 years (p <0.001). The C-index of the immune class was statistically higher than the TNM staging system (0.73 vs. 0.63, p <0.001). These results were validated in an internal and 2 external cohorts. The spatial distribution and abundance of TLSs significantly correlated with prognosis and provided a useful immune classification for iCCA. T follicular helper and regulatory T cells may play a critical role in determining the functional orientation of spatially different TLSs. Tertiary lymphoid structures (TLSs) are associated with favorable prognosis in a number of cancers. However, their role in intrahepatic cholangiocarcinoma (iCCA) remains unclear. Herein, we comprehensively evaluated the spatial distribution, abundance, and cellular composition of TLSs in iCCA, and revealed the opposite prognostic impacts of TLSs located within or outside the tumor. This difference could be mediated by the different immune cell subsets present within the spatially distinct TLSs. Based on our analysis, we were able to stratify iCCAs into 4 immune subclasses associated with varying prognoses.

The relationship of the tertiary lymphoid structures with the tumor-infiltrating lymphocytes and its prognostic value in gastric cancer.

To explore the relationship between the tertiary lymphoid structures (TLSs) and tumor-infiltrating lymphocytes (TILs), and their distribution characteristics as well as the prognostic value in gastric cancer (GC). The TLSs and four subtypes of TILs were assessed by immunohistochemical (IHC) staining. The presence of MECA-79 positive high endothelial venules (HEVs) identified among the ectopic lymphocyte aggregation area in the GC tissue was defined as valid TLSs. The number of labeled TILs was observed in 5 fields of the most positive cells in the tumor center, invasive edge and within the TLSs, at a field of vision ×40. The TLS distribution was significantly higher in the tumor invasive edge than the tumor center (p < 0.001). Similarly, the infiltrating density of CD8+ T cells and GrB+ T cells was statistically significantly higher in the tumor infiltrating edge than the tumor center. The total number of TILs and FOXP3+ T cells showed a contrary distribution. There was a positive correlation of the density of TLSs and TILs with both the location and the immune phenotype. A higher frequency of TILs and TLSs is often associated with favorable clinicopathologic parameters. Higher numbers of peri-TLSs (p = 0.007), peri-CD8+ (p = 0.019) and peri-GrB+TILs (p = 0.032) were significantly correlated with the favorable overall survival. Multivariate analysis revealed that the densities of TILs (p = 0.019) and TLSs (p = 0.037) were independent prognostic predictor for GC patients. We provide evidence that TLSs were positively associated with lymphocyte infiltration in GC. Thus, the formation of TLSs predicts advantageous immune system function and can be considered as a novel biomarker to stratify the overall survival risk of untreated GC patients.

025 ALA-PDT inhibits skin squamous cell carcinoma (cSCC) via regulating formation of tertiary lymphoid structures

Topical ALA-mediated PDT, ALA-PDT, is a novel therapeutic modality widely used to treat actinic keratosis, Bowen’s Disease, superficial skin SCC, and other cancerous and precancerous skin diseases. Several studies have proved that ALA-PDT can inhibit SCC growth. Subsequent research suggested that ALA-PDT not only directly induced tumor cells apoptosis, but also improve tumor microenvironment through regulation of immune cells. However, the anti-tumor immune function of ALA-PDT is still need to be elucidated. Here, we found that tertiary lymphoid structures (TLSs), which are ectopic lymphoid organs that develop in non-lymphoid tissues at sites of chronic inflammation including tumors, play a pivotal role in anti-tumor immune function of ALA-PDT. We analyzed 77 samples of cSCC patient in our hospital. TLS was observed in 79% of the patient samples, and the density of TLS is negatively correlation with the Brodes classification of cSCC. Intriguingly, immunohistochemistry showed that ALA-PDT could promote the formation of TLS in vivo. We also found that promotion effect of ALA-PDT on TLS is mediated by M1 macrophage, which function as lymphoid tissue inducer cells in TLS formation and recruited by ALA-PDT. Further investigation substantiated that PDT-secreted exosomes were involved in M1 macrophage polarization. Our study elucidated a mechanism that ALA-PDT influence M1 macrophage polarization via PDT-secreted exosomes, which could facilitate the formation of TLS. Thus, our research may contribute to in-depth molecular understanding of the ALA-PDT on anti-tumor immune function.

Metformin changes the immune microenvironment of colorectal cancer in patients with type 2 diabetes mellitus.

Accumulating evidence suggests that metformin reduces the incidence and mortality of colorectal cancer (CRC). However, underlying mechanisms have not been fully clarified. The aim of this study was to examine the pathological characteristics of resected CRC from patients treated with metformin for type 2 diabetes mellitus (DM). In total, 267 patients with DM underwent curative colectomy for Stage I‐III CRC and 53 (19.9%) patients had been treated medically including metformin. Pathological N‐stage was significantly lower in metformin‐treated patients (P < .05) with prolonged disease‐free survival (DFS) (P < .05). Immunohistochemistry showed that the densities of CD3(+) and CD8(+) tumor‐infiltrating lymphocytes (TILs) in the invasive front area were significantly higher in 40 patients treated with metformin compared with propensity score matched cases without metformin (P < .05). The density of tertiary lymphoid structures (TLS) in tumor stroma was markedly increased in metformin‐treated patients (P < .001). In those tumors, there were more CD68(+) tumor‐associated macrophages (TAM) infiltrated (P < .05), while the ratio of CD163(+) M2‐phenotype was markedly reduced (P < .001). Stromal fibrosis tended to be suppressed by metformin intake (P = .051). These findings suggested that metformin drastically changes the characteristics of infiltrating immune cells in CRC and reprograms the tumor microenvironment from immunosuppressive to immunocompetent status, which may lead to suppression of microscopic tumor spread and improve the outcomes of patients with CRC and type 2 DM.

The prognostic significance of peritumoral tertiary lymphoid structures in breast cancer.

Tumors and their surrounding area represent spatially organized "ecosystems", where tumor cells and the immune contextures of the different compartments are in a dynamic interplay, with potential clinical impact. Here, we aimed to investigate the prognostic significance of peritumoral tertiary lymphoid structures (TLS) either alone or jointly with the intratumoral densities and spatial distribution of CD8 + and CD163 + cells in breast cancer (BCa) patients. TLS were identified peritumorally, within the area distancing up to 5mm from the infiltrative tumor border, counted and further characterized as adjacent or distal, in formalin-fixed, paraffin-embedded tumor tissue samples from a cohort of 167 patients, with histologically confirmed invasive ductal BCa. TLS and tumor-infiltrating immune cells were determined by H&E and immunohistochemistry. Clinical follow-up was available for 112 of these patients. Patients with peritumoral TLS exhibited worse disease-free survival (DFS) and overall survival (OS) as compared to patients lacking TLS. Moreover, the density of peritumoral TLS was found to be crucial for prognosis, since patients with abundant TLS exhibited the worst DFS and OS. By combining the density of adjacent TLS (aTLS) with our recently published intratumoral signatures based on the differential distribution of CD8 + and CD163 + in the tumor center and invasive margin, we created two improved immune signatures with superior prognostic strength and higher patient population coverage. Our observations strengthen the notion for the fundamental role of the dynamic interplay between the immune cells within the tumor microenvironment (center/invasive margin) and the tumor surrounding area (peritumoral TLS) on the clinical outcome of BCa patients.

1452P - Prognostic significance of elements of the adaptive immunity in the microenvironment of early-stage non-small cell lung cancer

BackgroundThe characterization of adaptive immunity in the tumor microenvironment of non small cell lung cancer (NSCLC) is considered of outmost importance for the stratification of patients for immunotherapeutic approaches. For this, simple, feasible, inexpensive, reproducible and pathology based methodologies are needed, such as the evaluation of routine H&E stained slides, an approach that has been recently used for the interpretation of the immune-related pathologic response in the neoadjuvant immunotherapy setting. MethodsWe aimed to determine the prognostic significance of intratumoral and peritumoral tertiary lymphoid structures (TLS), plasma cells (PCs) and necrosis in a series of 140 patients with early stage, surgically resectable NSCLC. The evaluation of TLS (3-tiered score), PCs (4-tiered score) and necrosis (absent, focal, diffuse) was performed in hematoxylin-eosin (H&E) sections from surgical specimens of pulmonary wedge resection, lobectomy or pneumonectomy. Epidemiological data have been retrieved for 76 patients so far. ResultsIn most of the tumors examined, presence of TLS and aggregates of PCs was noted (91% and 75%, respectively). The presence and density of TLS and PCs in the tumor microenvironment correlated with improved survival (p<0.001 and p=0.002 respectively, Kaplan-Meier). The presence of TLS also correlated positively with PC infiltrates (p<0.001, CC=0.644, Spearman). Importantly, all patients with diffuse large PCs aggregates (score 3) are alive for the follow-up period. On the contrary, the presence of diffuse necrosis proved to have an adverse effect on overall survival (p=0.004, Kaplan-Meier) and showed no significant correlation with the presence of TLS and PCs. ConclusionsThe presence of elements of the adaptive immunity such as TLS and plasma cells is closely linked to clinical outcome in NSCLC. As plasma cell differentiation in the tumor environment correlated with the presence of TLS, this effector humoral immunity cell type might represent a surrogate marker of an effective immune response in the tumor microenvironment driven by the formation of Tertiary Lymphoid Structures. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Tertiary Lymphoid Structures in Colorectal Cancers and Their Prognostic Value.

BACKGROUND:Tumor-infiltrating lymphocytes (TIL) in tumour stroma are considered to be involved in the elimination of malignant cells and prevention of metastasis formation. TIL consist of T lymphocytes including cytotoxic lymphocytes that are a constituent part of the effector mechanism of anti-tumour immunity and B lymphocytes that can form tertiary lymphoid structures (TLS). TLS has been described in several solid tumours and colorectal carcinoma (CRC), and the influence on the local and systemic anti-cancer response.AIM:This study aimed to quantify the presence of TLS in CRC patients and to determine their role in tumour progression.PATIENTS AND METHODS:The study included 103 patients with CRC who underwent surgery at the University Clinic of Digestive Surgery in Skopje, whose operative material was analysed at the Institute of Pathology, Medical Faculty in Skopje. The density of TLS was determined and correlated with the neoplasm status of local growth (T), positive lymph nodes, lymphatic invasion, and stage of the disease and tumour grade.RESULTS:The density of TLS was significantly higher in patients with higher stage, lower T status, and negative lymph nodes, in patients with no lymphatic invasion and with better-differentiated tumours.CONCLUSION:The density of TLS plays an important role in controlling the tumour growth, and it can be a parameter for neoplasm progression in CRC patients. The density of TLS influences the control of tumour progression.

Abstract 1189: Deciphering the impact of immune editing on liver cancer clonal evolution using immunogenomics

Abstract Background and aims: Clonal evolution of a tumor ecosystem depends not only on somatic mutations driving uncontrolled growth, but on a full array of selection pressures, principally immune and resource mediated. We aimed at mapping the spatio-temporal interactions between cancer and immune cells in hepatocellular carcinoma (HCC) by quantifying regional adaptive immune editing, and how this impacts clonal evolution. Methods: We integrated data from RNAseq, targeted DNA sequencing, SNP array and histological evaluation from multiple regions of 10 HCC treatment-naive surgical specimens (55 samples, median of 4 tumor and 2 non-tumor regions per patient), 6 of whom with Hepatitis B virus infection (HBV). Immune cells were assessed with immunofluorescence for T (CD3) and B (CD19) markers. MAGEA3 was down-regulated in 3 liver cancer cell lines using shRNA and proliferation assessed with the MTS assay. Analyses included: intra-tumoral and HBV differential gene expression, prediction of immunogenicity of expressed mutations (i.e., tumor neoantigens) and HBV antigens, T and B cell receptor sequencing and survival and network analysis on the liver cancer TCGA dataset. Results &amp; Conclusions: There is a tumor-driven adaptive immune response contributing to HCC heterogeneity, mainly recruited by subclonal mutations as compared to an interplay between clonal mutations and HBV epitopes. Indeed, we found different regional configurations of tumor infiltrating lymphocytes with higher density of Tertiary Lymphoid Structures in areas enriched in highly immunogenic tumor neoantigens. Furthermore, regional differences in gene expression of heterogeneous tumors can capture stronger prognostic signals than best-in-class single biopsy based predictors tested on TCGA LIHC HCC data. This demonstrates that the breadth of molecular states in a single tumor can easily approach that of a large population sample of tumors. We also found evidence that some tumors' spatiotemporal expression profile is directly correlated with HBV expression, including the extreme case where some regions of a HBV infected patient have zero HBV expression, suggesting regional selection of infected clones via resource constraints. Finally we found that some tumoral evolution is dominated by cancer testis antigen (CTA) dysregulation led by MAGEA3/6, which we determined is a key causal driver of a major regulatory subnetwork from a Bayesian gene interaction network we inferred from TCGA LIHC HCC data. Hypothesizing a oncodriver role for MAGEA3, we confirmed that MAGEA3 downregulation has anti-tumoral effects in HCC experimental models. Citation Format: Bojan Losic, Amanda J. Craig, Sebastiao N. Martins-Filho, Carlos Villacorta-Martin, Nicholas Akers, Xintong Chen, Mehmet E. Ahsen, Ismail Labgaa, Delia D'Avola, Sergio A. Lira, Glaucia C. Furtado, Ashley Stueck, Stphen C. Ward, Maria I. Fiel, Ganesh Gunasekaran, Daniela Sia, Eric E. Schadt, Myron Schwartz, Josep M. Llovet, Swan Thung, Gustavo Stolovitzky, Augusto Villanueva. Deciphering the impact of immune editing on liver cancer clonal evolution using immunogenomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1189.

Tertiary Lymphoid Structures: An Anti-tumor School for Adaptive Immune Cells and an Antibody Factory to Fight Cancer?

Tertiary lymphoid structures (TLS) present in human solid tumors are essential for the shaping of a favorable immune micro-environment to control tumor development in most cases. They represent a formidable school for T-cell priming, B cell activation, and differentiation into plasma cells and an exquisitely located factory for antibody production. The manipulation of TLS neogenesis and maintenance represents, therefore, an exciting task to set up efficient anti-cancer vaccine strategies leading to long-lasting anti-tumor adaptive responses. To achieve this goal, a number of important issues are still pending. How TLS-T and -B cells and antibodies locally produced are related to the improved survival of cancer patients with high density of TLS is still unclear. In addition, the mechanisms by which tumors escape the immune surveillance exerted by TLS are still poorly understood and the role of immune suppressive cytokines, regulatory T cells, and/or antibodies in this process remains to be explored. The identification of the key parameters that distinguish TLS with anti- or possible pro-tumor activity is also essential to make the therapeutic targeting of TLS a success. Finally, how TLS-based therapeutic approaches can be associated with targeted therapies or immunointerventions, such as the use of ICP blockers to improve anti-tumor responses, is an open question. We will discuss these different issues in the present review.

Tumor-infiltrating lymphocyte subsets and tertiary lymphoid structures in pulmonary metastases from colorectal cancer.

The presence of tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) reflects an active inflammatory tumor microenvironment. High density of TILs as well as presence of TLS is associated with improved survival in various solid cancer types. We aimed to describe the density and distribution of TILs and TLS in pulmonary metastases (PMs) from primary colorectal cancer (CRC) and its correlation with clinicopathological variables. Fifty-seven CRC pulmonary metastasectomy specimen (PM) and 31 matched primary CRC specimen were included. Cluster of differentiation (CD)3+, CD8+, CD45RO+ and FoxP3+ TILs were evaluated by immunohistochemistry and density was scored semiquantitatively. TLS were evaluated based on morphological criteria. Survival time was defined from pulmonary metastasectomy to death or last follow up. A marked infiltration with CD3+, CD8+, CD45RO+ and FoxP3+ TILs was evident in CRC PM and matched primary CRC. Further assessment of the immune infiltrate in PM showed that a high density of FOXP3+ TILs at the invasive margin [HR 2.40 (1.11–6.96); P = 0.031] and low density of CD8+ cells in TLS [HR 0.30 (0.14–0.79); P = 0.016] were associated with a worse prognosis in univariate analysis. Moreover, a low CD8/FoxP3-ratio of TILs at the invasive margin (P = 0.042) and in TLS (P = 0.027) conferred an impaired prognosis after pulmonary metastasectomy. Our findings suggest that CRC PM harbor an immune active microenvironment. The balance of CD8+ and FoxP3+ T-cells at the tumor border and in TLS provides prognostic information in patients with CRC PM.Electronic supplementary materialThe online version of this article (doi:10.1007/s10585-016-9813-y) contains supplementary material, which is available to authorized users.

SP0164 Good Prognostic Value of Tertiary Lymphoid Structures in Human Lung Cancer

It is now well established that immune responses can take place at distance of secondary lymphoid organs, in tertiary lymphoid structures (TLS). We have previously shown that such structures can...

Abstract LB-498: Density of tertiary lymphoid structures is associated with activated and effector-memory T lymphocyte infiltration in human lung tumor

Abstract Introduction: An increasing number of studies have demonstrated a strong correlation between T cell infiltrate and clinical outcome in several types of human solid cancers. Nevertheless, the mechanisms governing T-cell infiltration and activation into tumors remain poorly characterized. In lung cancer, our team has observed the presence of tertiary lymphoid structures called Ti-BALT (Tumor-induced Bronchus-Associated Lymphoid Tissues). These structures present features of an ongoing immune response and their density is associated with long-term survival for lung cancer patients, suggesting their implication in local T cell recruitment and activation. We recently published a specific gene expression signature associated with T cell presence in Ti-BALT, which includes lymphoid chemokines, adhesion molecules, and integrins (De Chaisemartin L, et al. Cancer Research 2011). This chemoattractant gene expression signature strongly suggests an active recruitment of immune cells in these structures. Our aim was to study the influence of these structures on the composition, density and functionality of the immune infiltrate in lung tumors. Methods: The expression of relevant molecules was assessed on fresh tumor-infiltrating lymphocytes by multicolor flow cytometry, on tissue sections by immunohistochemistry and on frozen tumors by Low Density Array analysis. Results: Large-scale flow cytometry analysis revealed an increased infiltration of T and B but not NK cells in tumors with a high density of Ti-BALT as compared to tumors with a low density. A significant increase proportion of activated and effector-memory T cell subsets was observed in Ti-BALT high versus low tumors. Whereas most T cells located in Ti-BALT had a naive and early memory T cell phenotype, as observed in canonical secondary lymphoid organs, T cells located outside Ti-BALT were significantly enriched in effector-memory T cell phenotype. Finally, Ki-67+ proliferating T cells were found in close contact with mature dendritic cells in Ti-BALT, suggesting a local priming of T cells in these structures. Conclusion: Together, these data suggest that Ti-BALT represent a privileged area for T cell recruitment and activation in the primary site of the tumor. This mechanism could lead to the establishment and maintenance of a protective anti-tumor immune response directly in the tumor. These findings give news insights about mechanisms of T cell infiltration and activation in tumor microenvironment, suggesting new strategies to enhance the efficacy of cancer immunotherapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-498. doi:1538-7445.AM2012-LB-498