Background-GPR30 is a novel G protein-coupled estrogen receptor (ER) associated with metastases in breast cancer (BC) and poor survival in endometrial and ovarian tumors. The association of GPR30 expression with inflammatory breast cancer (IBC), an aggressive and commonly hormone-independent form of BC, has not been studied.

Purpose: To evaluate protein expression of PD-L1 and CD20 as prognostic biomarkers of patient outcome in inflammatory breast cancer (IBC) samples. Methods: PD-L1 and CD20 protein expression was measured by immunohistochemistry in 221 pretreatment IBC biopsies. PD-L1 was assessed in tumor cells (PD-L1+ tumor cells) and tumor stromal infiltrating lymphocytes (PD-L1+ TILs); CD20 was scored in tumor-infiltrating B cells. Kaplan–Meier curves and Cox proportional hazard models were used for survival analysis. Results: PD-L1+ tumor cells, PD-L1+ TILs, and CD20+ TILs were found in 8%, 66%, and 62% of IBC, respectively. PD-L1+ tumor cells strongly correlated with high TILs, pathological complete response (pCR), CD20+ TILs, but marginally with breast cancer-specific survival (BCSS, P=0.057). PD-L1+ TILs strongly correlated with high TILs, CD20+ TILs, and longer disease-free survival (DFS) in all IBC and in triple-negative (TN) IBC (P<0.035). IBC and TN IBC patients with tumors containing both CD20+ TILs and PD-L1+ TILs (CD20+TILs/PD-L1+TILs) showed longer DFS and improved BCSS (P<0.002) than patients lacking both, or those with either CD20+ TILs or PD-L1+ TILs alone. In multivariate analyses, CD20+TILs/PD-L1+TILs status was an independent prognostic factor for DFS in IBC (hazard ratio (HR): 0.53, 95% CI 0.37–0.77) and TN IBC (HR: 0.39 95% CI 0.17–0.88), and for BCSS in IBC (HR: 0.60 95% CI 0.43–0.85) and TN IBC (HR: 0.38 95% CI 0.17–0.83). Conclusion: CD20+TILs/PD-L1+TILs status represents an independent favorable prognostic factor in IBC and TN IBC, suggesting a critical role for B-cells in anti-tumor immune responses. Anti-PD-1/PD-L1 and B-cell-activating immunotherapies should be explored in these settings.

Inflammatory breast cancer (IBC) in humans is the most aggressive form of mammary gland cancer and shares clinical, pathologic, and molecular patterns of disease with canine inflammatory mammary carcinoma (CIMC). Despite the use of multimodal therapeutic approaches, including targeted therapies, the prognosis for IBC/CIMC remains poor. The aim of this review is to critically analyze IBC and CIMC in terms of biology and clinical features. While rodent cancer models have formed the basis of our understanding of cancer biology, the translation of this knowledge into improved outcomes has been limited. However, it is possible that a comparative "one health" approach to research, using a natural canine model of the disease, may help advance our knowledge on the biology of the disease. This will translate into better clinical outcomes for both species. We propose that CIMC has the potential to be a useful model for developing and testing novel therapies for IBC. Further, this strategy could significantly improve and accelerate the design and establishment of new clinical trials to identify novel and improved therapies for this devastating disease in a more predictable way.

Background Inflammatory breast cancer (IBC) shows a high incidence in Tunisia and Egypt but epidemiological and molecular characteristics have not been described in Algeria. Methods We compared 117 IBC and 59 non-IBC locally advanced breast cancers (LABC), for estrogen and progesterone receptors, HER2, and EGFR protein expression by immunohistochemistry, and HER2 gene amplification by chromogenic in situ hybridization. Demographic, clinico-pathological and molecular variables were compared with chi-square and Fisher’s exact tests to test for significance (P < 0.05, two-tailed). Overall survival (OS) and disease-free survival (DFS) were plotted using Kaplan–Meier curves and compared using the log-rank test. Results Tumor emboli were detected in 77% of IBC. Palpable masses were found in all LABC but only in 32% of IBC (P<0.001). Recurrences were higher in LABC than in IBC (48% vs. 35%; P=0.14) but OS was worse in IBC (68% vs. 71%; P=0.06). There were no significant differences between IBC and LABC by demographics or by clinico-pathologic parameters. The majority of IBC and LABC tumors were luminal A (62% and 64%), followed by basal (~18%, each), triple negative (~18%, each) and HER2+ (~10%, each) subtypes. In multivariate analyses, grade was associated with worse OS (P=0.04), and DFS (P<0.001) in IBC; chemo-and radio-therapy were associated with improved OS and DFS, respectively (P<0.05 for each) in LABC. Conclusions IBC in Algeria shows similar characteristics to IBC described for Egypt and Tunisia with subtle molecular differences. Current therapeutic treatments were not very effective in this population and new approaches are much needed.

BackgroundInflammatory breast cancer (IBC) is a highly angiogenic disease; thus, antiangiogenic therapy should result in a clinical response. However, clinical trials have demonstrated only modest responses, and the reasons for these outcomes remain unknown. Therefore, the purpose of this retrospective study was to determine the prognostic value of protein levels of vascular endothelial growth factor (VEGF-A), one of the main targets of antiangiogenic therapy, and its receptors (VEGF-R1 and -R2) in IBC tumor specimens.Patients and MethodsSpecimens from IBC and normal breast tissues were obtained from Algerian patients. Tumor epithelial and stromal staining of VEGF-A, VEGF-R1, and VEGF-R2 was evaluated by immunohistochemical analysis in tumors and normal breast tissues; this expression was correlated with clinicopathological variables and breast cancer-specific survival (BCSS) and disease-free survival (DFS) duration.ResultsFrom a set of 117 IBC samples, we evaluated 103 ductal IBC tissues and 25 normal specimens. Significantly lower epithelial VEGF-A immunostaining was found in IBC tumor cells than in normal breast tissues (P <0.01), cytoplasmic VEGF-R1 and nuclear VEGF-R2 levels were slightly higher, and cytoplasmic VEGF-R2 levels were significantly higher (P = 0.04). Sixty-two percent of IBC tumors had high stromal VEGF-A expression. In univariate analysis, stromal VEGF-A levels predicted BCSS and DFS in IBC patients with estrogen receptor-positive (P <0.01 for both), progesterone receptor-positive (P = 0.04 and P = 0.03), HER2+ (P = 0.04 and P = 0.03), and lymph node involvement (P <0.01 for both). Strikingly, in a multivariate analysis, tumor stromal VEGF-A was identified as an independent predictor of poor BCSS (hazard ratio [HR]: 5.0; 95% CI: 2.0-12.3; P <0.01) and DFS (HR: 4.2; 95% CI: 1.7-10.3; P <0.01).ConclusionsTo our knowledge, this is the first study to demonstrate that tumor stromal VEGF-A expression is a valuable prognostic indicator of BCSS and DFS at diagnosis and can therefore be used to stratify IBC patients into low-risk and high-risk groups for death and relapses. High levels of tumor stromal VEGF-A may be useful for identifying IBC patients who will benefit from anti-angiogenic treatment.