Abstract P5-23-05: Prognostic value of PD-L1 expression in male breast cancer

Background

Growing evidence have shown promise for targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling in several tumors. In female breast cancer, PD-L1 expression has been correlated with poor clinical outcome. However, whether PD-L1 has any indication for prognosis in male breast cancer (MBC) patients remains unknown. The purpose of this study was to examine the expression levels of PD-L1 in MBC and to identify the relationship between PD-L1 expression and patient survival.

Methods

We retrospectively identified 110 male breast cancer patients diagnosed between 2000 and 2013 at Salah Azaïz Cancer Institute. PD-L1 expression was evaluated by immunohistochemistry (IHC) using CD274 antibody. Specimens were scored as IHC low or high, when < 5% or ≥ 5% of cells were PD-L1 positive, respectively. The association between expression of PD-L1 and survival was investigated using Kaplan-Meier survival and COX proportional hazard regression analyses.

Results

Median follow up was 12.5 months [range 1-132 months]. High expression of PD-L1 was observed in 64.5% of MBC samples (71/110). PD-L1 expression was significantly associated with advanced clinical stage (p=0.012), higher histological grade (p=0.014), higher Ki67 expression (p=0.023) and hormone-receptor negative status (p=0.024). Patients with high PD-L1 expression had significantly shorter overall survival (OS) than patients with low expression (p=0.002, hazard ratio (HR) =5 [2.624–10.642]). Multivariate analysis identified PD-L1 as an independent prognostic factor for OS (p<0.001, HR = 0.775 [0.680–0.870]).

Conclusion

Our results indicate that high PD-L1 expression may be a prognostic indicator for reduced OS. Thus, PD-L1 expression is a promising novel biomarker with prognostic significance in MBC and may suggest a potential therapeutic target of anti-PD-L1 antibody therapy in MBC patients.

Citation Format: Abdeljaoued S, Bettaieb I, Adouni O, Goucha A, Chiba D, Bouzaiene H, Ben Hassouna J, Boussen H, Rahal K, Gamoudi A. Prognostic value of PD-L1 expression in male breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-23-05.

Abstract P3-15-01: Prognostic significance of CD8+ tumor-infiltrating lymphocytes (TILs), CD4+ TILs and TILs in male breast cancer

Background

Several studies have demonstrated that the presence and the amount of tumor-infiltrating lymphocytes (TILs) are a potential biomarker of prognostic significance in some solid tumors. Data suggests that high levels of TILs are associated with favorable prognosis. However, whether TILs have any indication for prognosis in male breast cancer (MBC) patients remains unknown. In this study, we investigated the relationship between the expression and degree of CD8+ TILs, CD4+ TILs, and TILs and evaluated the prognostic value of these three factors in MBC.

Methods

We retrospectively identified 110 male breast cancer patients diagnosed between 2000 and 2013 at Salah Azaïz Cancer Institute. Stromal (str) CD8+ and CD4+ TILs were evaluated immunohistochemically. Two pathologists independently evaluated TILs levels using H&E stained slides following 2014 International TILs Working Group guidelines. Kaplan Meier and univariate and multivariate Cox regression analysis were applied to determine the association of CD8+ TILs, CD4+ TILs and TILs with clinicopathological features and overall survival (OS).

Results

The median for presence of str-CD8+TILs was 7% (0%-40%), str-CD4+TILs was 2% (0%-20%) and str-TILs was 10% (1%-40%). Only 12% of MBC patients had high str-CD8+TILs and 11% had high str-CD4+TILs. Fifty three percent had low str-TILs and 47% had moderate str-TILs. No lymphocyte predominant breast cancer was identified. Regarding intrinsic molecular subtypes, TNBC subtype and HER2 enriched tumors compared with Hormone receptor positive tumors had higher median levels of str-CD8+TILs, str-CD4+ TILs and str-TILs at diagnosis. However, increased level of str-CD8+ TILs, str-CD4+TILs and str-TILs weren't associated with improved OS in IHC subtypes (p=0.597, p=0.498 and p=0.456 respectively). On univariate analysis, higher levels of str-CD8+TILs, str-CD4+ TILs and str-TILs were associated with better OS (p=0.035, p=0.043 and p=0.040 respectively). Multivariate analysis identified str-CD8+ TILs and str-TILs as independent prognostic factors for OS ([HR= 0.851 (0.706-0.997), p=0.000] and [HR= 0.69 (0.43-0.96), p=0.045] respectively) but not str-CD4+ TILs (p=0.276). A high level of str-TILs was correlated with high str-CD8+ (p = 0.025).

Conclusion

The level of TILs in male breast cancer is low, suggesting prominent immune regulation/suppression in this disease. Str-CD8+ T cells and str-TILs represent potential prognostic markers in male breast cancer patients.

Citation Format: Abdeljaoued S, Bettaieb I, Adouni O, Goucha A, Ghozzi R, Bouzaiene H, Hdiden M, Ben Hassouna J, Makhlouf R, El Benna F, Boussen H, Rahal K, Gamoudi A. Prognostic significance of CD8+ tumor-infiltrating lymphocytes (TILs), CD4+ TILs and TILs in male breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-15-01.

Abstract P6-19-03: Overexpression of FOXM1 is a potential prognostic marker in male breast cancer

Background

The Forkhead box M1 (FOXM1) transcription factor is known to play an important role in the development and progression of many cancer types including breast cancer. The important role of FOXM1 in cancer affirms its significance for clinical use and therapeutic intervention. Elevated expression of FOXM1 in female breast cancer correlates with undifferentiated tumor phenotype and negative clinical outcome. However, whether FOXM1 has any indication for prognosis in male breast cancer (MBC) patients is still unknown. The purpose of this study was to examine the expression levels of FOXM1 in MBC and to identify the relationship between FOXM1 expression and patient survival.

Methodsl

Immunohistochemical analysis for FOXM1 was performed in a total of 80 male breast cancer specimens, all with linked clinical outcome data. Kaplan-Meier method and Cox proportional hazards analysis were used to relate FOXM1 expression to clinicopathological variables and overall survival (OS).

Results

We observed high expression of the FOXM1 protein in 39 % of MBC samples (31/80). FOXM1 overexpression was significantly associated with higher histological grade (p=0.05), lymph node metastasis (p=0.04), tumor size (p=0.05), and estrogen receptor expression (p=0.04). Patients with FOXM1 expression had a significantly poorer overall survival than those without FOXM1 expression (p=0.02). Multivariate analyses indicated that FOXM1 positivity was an independent prognostic factor for OS (p=0.03).

Conclusion

These results show that FOXM1 may represent a novel MBC marker with prognostic significance that could be included into the limited marker panels for MBC.

Citation Format: Rahal K, Abdeljaoued S, Bettaieb I, Bouzaiene H, Adouni O, Miladi S, Goucha A, Bouaziz H, Makhlouf R, Hechiche M, Benna F, Boussen H, El May A, Gamoudi A. Overexpression of FOXM1 is a potential prognostic marker in male breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-19-03.

A GIS-based DRASTIC vulnerability and net recharge reassessment in an aquifer of a semi-arid region (Metline-Ras Jebel-Raf Raf aquifer, Northern Tunisia)

This paper aims to elaborate new generic DRASTIC aquifer vulnerability maps of the coastal aquifer of Metline-Ras Jebel-Raf Raf (Northeast of Tunisia) using the GIS technique, making the data analyses easier to handle and providing better capabilities of dealing with large spatial data. A similar study was carried out in 1999 in the same aquifer using a method based on the soil water balance equation to determine the net recharge parameter. Unfortunately, the lack of data in the study area made the results unsatisfactory. By applying the Williams and Kissel equation and the Rao relationship, we intend to demonstrate that we could correctly evaluate the net recharge parameter. Moreover, new data related to the aquifer hydraulic conductivity, the soil cover and the vadose zone lithology have become available, and allowed us to elaborate suitable DRASTIC maps.