Tumor Associated Macrophages and Topoisomerase II Alpha As Prognostic Factors in Advanced Stage Hodgkin's Lymphoma

Abstract

Background : Classic Hodgkin's lymphoma (cHL) is associated with a high cure rate, but approximately 20% of patients are refractory to initial treatment and 10-30% of patients will relapse after achieving complete remission (CR) , the search of new prognostic factors to identify these high risk patients remains challenging in daily practice, the aim of this study is to evaluate CD68 positive Tumor associated macrophages(TAM) and the cell proliferation marker topoisomerase II alpha as prognostic factor in advanced stage (cHL). Patient and Methods: This study included 82 patients with Advanced stage classic Hodgkin lymphoma presented to Medical Oncology Departments of the National Cancer Institute, Cairo University and Zagazig University hospitals in the period from 2012 to 2017. All patients received ABVD regimen as induction. Immunohistochemical (IHC) analysis was performed for all cases using Tissue microarrays (TMAs) sections and stained with anti‐ CD68 (clones KP1 and PGM1, Dako, Glostrup,Denmark). For Topo II testing, IHC staining was performed on deparaffinized sections using the avidin-biotin complex immunoperoxidase technique with separate antibodies recognizing CD30 and the isoform of Topo II. The percentage of cells expressing cytoplasmic CD30 and nuclear Topo II staining simultaneously was determined for each case. We examined four cutoff points of CD68 expression (<= 20% versus >20%), <5% low (score 1), 5-15% intermediate (score 2) & > 15% high (score 3), <5% low (score 1), 5-25% intermediate (score 2) & > 25% high (score 3) and <= 50% versus > 50%. For Topo II expression, two cut off points were analyzed (<= 30% versus >30%) and (<= 75% versus >75%). Results: The study included 41 males and 41 females with a ratio of 1: 1. The median age was 30.5 years (range: 18-60 years). CRwas achieved in 64.6% (53/82 of patients) and 35.4% of all patients (29/82) were refractory. Relapse was reported in17% of the CR cases (9/53). The significant statistical difference in disease-free survival (DFS) for CD68+was observed at a cut off value of 50%, where 60 patients had CD68 <= 50% and 22 patients had CD68 >50%. The mean DFS for patients with CD68 <= 50% was 49.33 months ± 2.18 months (confidence interval: 45.05 to 53.60 months) vs. 35.255 ± 4.94 months (confidence interval: 25.55 to 44.95 months) in patients with CD68 > 50% (p = 0.015). The low CD68 group included more patients in CR (67.9%, n=36 vs. 32.1%, n=17) , male to female ratio was equal(1:1) in both groups (<= 50% ,n=30:30) and (> 50% ,n=11:11), B symptoms also was equal in both groups (<= 50% , 81% ,n=49) and (> 50% 81% ,n=18), patients with CD68<= 50% had more extra nodal disease (22%, n=13 vs. 18%, n=4) and also more bulky disease (20%, n=12 vs. 4.5% n=1) compared with high (CD68>50%) group. The overall survival (OS) was not significant for all CD68 cutoff points. Higher CD68 is associated with decreased OS: 48 vs. 52 month (CI: 42 to 53 month, p=0.42) at cut off 50%. Topo II expression using the two cut off points was not statistically significant in relation to both DFS and OS , the higher topoII group included more patients in CR (80% ,n=42 topo II >30% vs. 20%, n=10 topo II<=30%) also,(67%, n=53 Topo II >= 75% vs. 33%, n=17 Topo II < 75%). Higher Topo II is associated with prolonged DFS (45 months vs. 36 month) confidence intervals: 40 to 50 months vs 27 to 46. Months) at cut off 30% (p=0.8). At cutoff 75%, the DFS was 46 vs. 38 months (Confidence intervals: 41.73 to 52.10 months vs. 30 to 47.7 months, p= 0.36). Higher Topo II is associated with decreased OS: 50 vs.54 months (CI: 46 to 54 month) at cutoff 75% (p=0.19). CD68 was only statistically significant in correlation to patient age (p = 0.05), and non significant to serum albumin ,hemoglobin level , white blood cells count ,international prognostic score (IPS). Topo II was not statistically significant with the previous patient characteristics. Conclusion : High level of CD68 expression in patients with advanced stage HL (>50%) was significantly associated with inferior DFS but not OS, Topo II does not have significant prognostic value in relation to both DFS or OS of advanced HL cases. DisclosuresNo relevant conflicts of interest to declare.