Anita Sajet

HLA-E and HLA-G Expression in Classical HLA Class I-Negative Tumors Is of Prognostic Value for Clinical Outcome of Early Breast Cancer Patients

Nonclassical HLAs, HLA-E and HLA-G, are known to affect clinical outcome in various tumor types. We examined the clinical impact of HLA-E and HLA-G expression in early breast cancer patients, and related the results to tumor expression of classical HLA class I. Our study population (n = 677) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1995. Tissue microarray sections of arrayed tumor and normal control material were immunohistochemically stained for HLA-E and HLA-G. For evaluation of HLA-E and HLA-G and the combined variable, HLA-EG, a binary score was used. Expression of classical HLA class I molecules was determined previously. HLA-E, HLA-G, and HLA-EG on breast tumors were classified as expression in 50, 60, and 23% of patients, respectively. Remarkably, only in patients with loss of classical HLA class I tumor expression, expression of HLA-E (p = 0.027), HLA-G (p = 0.035), or HLA-EG (p = 0.001) resulted in a worse relapse-free period. An interaction was found between classical and nonclassical HLA class I expression (p = 0.002), suggestive for a biological connection. We have demonstrated that, next to expression of classical HLA class I, expression of HLA-E and HLA-G is an important factor in the prediction of outcome of breast cancer patients. These results provide further evidence that breast cancer is immunogenic, but also capable of evading tumor eradication by the host’s immune system, by up- or downregulation of HLA class Ia and class Ib loci.

The Predictive Value of HLA Class I Tumor Cell Expression and Presence of Intratumoral Tregs for Chemotherapy in Patients with Early Breast Cancer

Purpose: We hypothesized that T-cell immune interaction affects tumor development and thus clinical outcome. Therefore, we examined the clinical impact of human leukocyte antigen (HLA) class I tumor cell expression and regulatory T-cell (Treg) infiltration in breast cancer. Experimental Design: Our study population (N = 677) is consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1994. Formalin-fixed, paraffin-embedded tumor tissue was immunohistochemically stained using HCA2, HC10, and Foxp3 monoclonal antibodies. Results: HLA class I expression was evaluated by combining results from HCA2 and HC10 antibodies and classified into three groups: loss, downregulation, and expression. Remarkably, only in patients who received chemotherapy, both presence of Treg (P = 0.013) and higher HLA class I expression levels (P = 0.002) resulted in less relapses, independently of other variables. Treg and HLA class I were not of influence on clinical outcome in patients who did not receive chemotherapy. Conclusions: We showed that HLA class I and Treg affect prognosis exclusively in chemotherapy-treated patients and are therefore one of the few predictive factors for chemotherapy response in early breast cancer patients. Chemotherapy may selectively eliminate Treg, thus enabling CTLs to kill tumor cells that have retained HLA class I expression. As a consequence, HLA class I and Treg can predict response to chemotherapy with high discriminative power. These markers could be applied in response prediction to chemotherapy in breast cancer patients. Clin Cancer Res; 16(4); 1272–80

NKG2D ligand tumor expression and association with clinical outcome in early breast cancer patients: an observational study

BackgroundCell surface NKG2D ligands (NKG2DL) bind to the activating NKG2D receptor present on NK cells and subsets of T cells, thus playing a role in initiating an immune response. We examined tumor expression and prognostic effect of NKG2DL in breast cancer patients.MethodsOur study population (n = 677) consisted of all breast cancer patients primarily treated with surgery in our center between 1985 and 1994. Formalin-fixed paraffin-embedded tumor tissue was immunohistochemically stained with antibodies directed against MIC-A/MIC-B (MIC-AB), ULBP-1, ULBP-2, ULBP-3, ULBP-4, and ULBP-5.ResultsNKG2DL were frequently expressed by tumors (MIC-AB, 50% of the cases; ULBP-1, 90%; ULBP-2, 99%; ULBP-3, 100%; ULBP-4, 26%; ULBP-5, 90%) and often showed co-expression: MIC-AB and ULBP-4 (p = 0.043), ULBP-1 and ULBP-5 (p = 0.006), ULBP-4 and ULBP-5 (p < 0.001). MIC-AB (p = 0.001) and ULBP-2 (p = 0.006) expression resulted in a statistically significant longer relapse free period (RFP). Combined expression of these ligands showed to be an independent prognostic parameter for RFP (p < 0.001, HR 0.41). Combined expression of all ligands showed no associations with clinical outcome.ConclusionsWe demonstrated for the first time that NKG2DL are frequently expressed and often co-expressed in breast cancer. Expression of MIC-AB and ULBP-2 resulted in a statistically significant beneficial outcome concerning RFP with high discriminative power. Combination of all NKG2DL showed no additive or interactive effect of ligands on each other, suggesting that similar and co-operative functioning of all NKG2DL can not be assumed. Our observations suggest that among driving forces in breast cancer outcome are immune activation on one site and tumor immune escape on the other site.

High nuclear expression levels of histone-modifying enzymes LSD1, HDAC2 and SIRT1 in tumor cells correlate with decreased survival and increased relapse in breast cancer patients

BackgroundBreast cancer is a heterogeneous disease with a highly variable clinical outcome in which both genetic and epigenetic changes have critical roles. We investigated tumor expression levels of histone-modifying enzymes LSD1, HDAC2 and SIRT1 in relation with patient survival and tumor relapse in a retrospective cohort of 460 breast cancer patients. Additionally, we correlated expression levels with tumor differentiation and tumor cell proliferation.MethodsImmunohistochemical staining for LSD1, HDAC2 and SIRT1 was performed on tissue microarrays of tumor and corresponding normal formalin-fixed paraffin-embedded tissues from breast cancer patients. Median nuclear expression levels in tumor tissues were used to divide the patients into low and high expression categories. In combined expression analyses, patients were divided into four subgroups: 1, all enzymes below-median; 2, one enzyme above-median; 3, two enzymes above-median; 4, all three enzymes above-median. The Cox proportional hazard model was used for univariate and multivariate survival analyses. The Pearson Chi-square method was used to assess correlation of combined expression levels with tumor cell proliferation and tumor differentiation.ResultsExpression of LSD1 and SIRT1, but not of HDAC2, was significantly increased in tumor tissues compared to their normal counterparts (both p < 0.001). Multivariate survival analyses identified SIRT1 as independent prognostic factor for relapse-free survival (RFS) with a hazard ratio (HR) of 1.34 (95% CI = 1.04-1.74, p = 0.02). For overall survival (OS), no significant differences were found when the individual enzymes were analyzed. Analyses of combined expression levels of the three histone-modifying enzymes correlated with OS (p = 0.03) and RFS (p = 0.006) with a HR of respectively 1.49 (95% CI = 1.07-2.08) and 1.68 (95% CI = 1.16-2.44) in multivariate analyses and were also related to tumor differentiation (p < 0.001) and tumor cell proliferation (p = 0.002).ConclusionsWhen the combined expression levels were analyzed, high expression of LSD1, HDAC2 and SIRT1 showed shorter patient survival time and shorter time to tumor relapse and correlated with poor tumor differentiation and a high level of tumor cell proliferation. Expression of these histone-modifying enzymes might therefore be involved in breast cancer pathogenesis.

Age determines the prognostic role of the cancer stem cell marker aldehyde dehydrogenase-1 in breast cancer

BackgroundThe purpose of this study was to compare the expression and the prognostic effect of the breast cancer stem cell marker aldehyde dehydrogenase-1 (ALDH1) in young and elderly breast cancer patients.MethodsThe study population (N = 574) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1994. Median follow-up was 17.9 years (range: 0.1 to 23.5). Tissue microarray slides were immunohistochemically stained for ALDH1 expression and quantified by two independent observers who were blinded to clinical outcome. Assessment of the prognostic effect of ALDH1 expression was stratified according to age and systemic treatment.ResultsComplete lack of expression of ALDH1 was found in 40% of tumors. With increasing age more tumors showed complete absence of ALDH1 expression (P < .001). In patients aged > 65 years, ALDH1 status was not associated with any clinical outcome. Conversely, in patients aged < 65 years, ALDH1 positivity was an independent risk factor of worse outcome for relapse free period (hazard ratio = 1.71 (95% CI, 1.09 to 2.68); P = .021) and relative survival (relative excess risks of death = 2.36 (95% CI, 1.22 to 3.68); P = .016). Ten-year relative survival risk was 57% in ALDH1-positive patients compared to 83% in ALDH1-negative patients.ConclusionALDH1 expression and its prognostic effect are age-dependent. Our results support the hypothesis that breast cancer biology is different in elderly patients compared to their younger counterparts and emphasizes the importance of taking into consideration age-specific interactions in breast cancer research.

The influence of insulin-like Growth Factor-1-Receptor expression and endocrine treatment on clinical outcome of postmenopausal hormone receptor positive breast cancer patients: A Dutch TEAM substudy analysis

Background: Signaling via the Insulin‐like Growth Factor type 1 Receptor (IGF1R) plays a crucial role in cancer development. In breast cancer (BC), IGF1R and estrogen receptor expression are correlated. In this current study we explored the hypothesis that postmenopausal hormone receptor positive (HR+ve) BC patients with high IGF1R tumor expression still have estrogen driven IGF1R stimulated tumor growth when treated with tamoxifen, resulting in detrimental clinical outcome compared to patients treated with exemestane. Additionally, we assessed the added value of metformin as this drug may lower IGF1R stimulation.

Abstract P4-07-02: Expression of Cell Adhesion Molecules Predicts Prognosis in Early Breast Cancer Patients

Purpose: New prognostic and predictive factors are sought for improvement of tailored treatment in early breast cancer. We examined the clinical impact of cell adhesion molecules (CAM): E-cadherin, N-cadherin, Ep-CAM and CEA. Patients and Methods: Our study population (n=574) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1994. A tissue micro array (TMA) of formalin-fixed paraffin-embedded tumor tissue was immunohistochemically stained for expression of mentioned CAM. The percentage of membranous stained cells was microscopically analyzed. Based on the median score, all CAM were classified in two groups: low expression versus high expression. For CEA, high expression was further subdivided based on the intensity of staining: high expression and highest expression. Results: High expression was seen for E-cadherin, N-cadherin and Ep-CAM in 49%, 46%, 27% of patients respectively. Low expression, high expression and highest expression were found in respectively 48%, 45% and 8% of cases for CEA. Low expression of E-cadherin (p=0.015) and higher expression levels of N-cadherin, Ep-CAM, CEA (p=0.004; 0.046; 0.001 respectively) all resulted in a worse relapse free period (RFP) of patients. Multivariate analysis revealed only E-cadherin and CEA to be independent prognostic variables. A combination variable was created with expression of both markers: (1) E-cadherin high expression, (2) E-cadherin low or CEA low or high expression (3) CEA highest expression. This variable revealed to be an independent prognostic parameter with high discriminative power for RFP (P Conclusion: We have demonstrated that E-cadherin, N-cadherin, Ep-CAM and CEA are of prognostic influence on outcome concerning RFP in breast cancer patients. A combined variable of E-cadherin and CEA expression revealed to have prognostic influence on RFP with high discriminative power and therefore is a candidate parameter for future outcome prediction of patients. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-07-02.

Abstract 5317: HLA-E and HLA-G tumor expression is of prognostic value for clinical outcome of early breast cancer patients, but exclusively in classical HLA class I tumor-negative patients

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background Non-classical human leukocyte antigens (HLA), HLA-E and HLA-G, are known to affect clinical outcome in various tumor types. We examined the clinical impact of HLA-E and HLA-G expression in early breast cancer patients, and related the results to tumor expression of classical HLA class I molecules, as together these cell surface molecules may determine natural killer (NK) cell responses. Material and Methods Our study population (n=677) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1995. Tissue micro array (TMA) sections of formalin-fixed paraffin-embedded tumors were immunohistochemically stained for HLA-E and HLA-G. For evaluation of HLA-E and HLA-G expression and the combined variable, HLA-EG, a binary score was used. Expression of classical HLA class I expression was previously determined. Results HLA-E, HLA-G and HLA-EG were expressed in breast tumors in 50%, 60% and 23% of patients respectively. Remarkably, only in patients with loss of classical HLA class I tumor expression, expression of HLA-E (p=0.027), HLA-G (p=0.035) and HLA-EG (p=0.001) resulted in a worse relapse free period. An interaction was found between classical and non-classical HLA class I expression (p=0.002), suggestive for a biological connection. Conclusions We have demonstrated that expression of HLA-E and HLA-G are important factors in the prediction of clinical outcome of breast cancer patients, but exclusively in patients with classical HLA class I negative tumors. HLA-E and HLA-G expression may specifically prevent NK-cell recognition by the host in this subset of tumors. These results provide further evidence that breast cancer is highly immunogenic, but also capable of evading tumor eradication by the host immune system in which both T cells and NK cells play a role. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5317.