Toll-Like Receptor-9 Expression Does Not Predict for Breast Cancer Specific Outcome in African-American Triple-Negative Breast Cancer Patients

Purpose/Objective(s)Prior research has indicated low tumor Toll-like receptor 9 (TLR9) expression is associated with worsened disease-specific survival in patients with triple-negative breast cancer (TNBC), but not hormone receptor positive (ER+, PgR+, Her-2-) breast cancer in a Finnish Caucasian population. An inverse relationship between survival and TLR-9 status has been detected in renal cell carcinoma in a similar, highly homogenous population. The aim of this study was to evaluate TLR9 expression in a population of African American TNBC patients and assess its relationship to survival and recurrence.Materials/MethodsAfrican-American females with TNBC treated at our institution with tissue available for analysis were identified in a pathology database and isolated for immunohistochemical staining and evaluation of TLR9 expression. TLR9 expression scores were compared with clinicopathological parameters and breast cancer specific survival. Data was retrospectively evaluated for disease-free and breast cancer specific survival. We hypothesized patients with low tumor levels of TLR9 expression will experience worse outcomes.ResultsSixty-six patients were included in our study and 43 patients had tissue evaluable for review. Median age at the time of diagnosis was 51 years. Most patients (n = 39, 86.7%) were early stage, and the majority were also node-negative (n = 30, 66.7%). The vast majority had infiltrating ductal carcinoma (n = 43, 89.6%). Most patients had mastectomy (n = 28, 60.9%) with the minority undergoing lumpectomy. All patients received some form of chemotherapy (26.2% in the neoadjuvant setting and 74.4% adjuvant systemic therapy). Radiation therapy was used in 66% of patients in the post-operative setting. At a median follow-up of 3.5 years, 25 patients experienced some type of recurrence, with patterns of first recurrences as follows: 7 local, 1 regional, 9 distant, and 3 mixed local and distant. Eleven patients had ipsilateral breast tumor recurrence. The TLR9 staining range was similar as previously detected in the Finnish cohort. However, tumor TLR9 staining score was not significantly associated with local recurrence, disease-free survival, or overall survival.ConclusionsUnlike the highly homogenous Finnish population, TLR9 status was not associated with outcome in this cohort of African-American females with TNBC. It is suspected that TNBC tumors of African-American females behave in a different biologic manner than other subgroups; thus, further research into TLR9 will be undertaken in multiple patient populations with TNBC. Although the study results are limited by low patient numbers, it appears elevated tumor TLR9 expression is not associated with freedom from relapse in African American patients with TNBC. Purpose/Objective(s)Prior research has indicated low tumor Toll-like receptor 9 (TLR9) expression is associated with worsened disease-specific survival in patients with triple-negative breast cancer (TNBC), but not hormone receptor positive (ER+, PgR+, Her-2-) breast cancer in a Finnish Caucasian population. An inverse relationship between survival and TLR-9 status has been detected in renal cell carcinoma in a similar, highly homogenous population. The aim of this study was to evaluate TLR9 expression in a population of African American TNBC patients and assess its relationship to survival and recurrence. Prior research has indicated low tumor Toll-like receptor 9 (TLR9) expression is associated with worsened disease-specific survival in patients with triple-negative breast cancer (TNBC), but not hormone receptor positive (ER+, PgR+, Her-2-) breast cancer in a Finnish Caucasian population. An inverse relationship between survival and TLR-9 status has been detected in renal cell carcinoma in a similar, highly homogenous population. The aim of this study was to evaluate TLR9 expression in a population of African American TNBC patients and assess its relationship to survival and recurrence. Materials/MethodsAfrican-American females with TNBC treated at our institution with tissue available for analysis were identified in a pathology database and isolated for immunohistochemical staining and evaluation of TLR9 expression. TLR9 expression scores were compared with clinicopathological parameters and breast cancer specific survival. Data was retrospectively evaluated for disease-free and breast cancer specific survival. We hypothesized patients with low tumor levels of TLR9 expression will experience worse outcomes. African-American females with TNBC treated at our institution with tissue available for analysis were identified in a pathology database and isolated for immunohistochemical staining and evaluation of TLR9 expression. TLR9 expression scores were compared with clinicopathological parameters and breast cancer specific survival. Data was retrospectively evaluated for disease-free and breast cancer specific survival. We hypothesized patients with low tumor levels of TLR9 expression will experience worse outcomes. ResultsSixty-six patients were included in our study and 43 patients had tissue evaluable for review. Median age at the time of diagnosis was 51 years. Most patients (n = 39, 86.7%) were early stage, and the majority were also node-negative (n = 30, 66.7%). The vast majority had infiltrating ductal carcinoma (n = 43, 89.6%). Most patients had mastectomy (n = 28, 60.9%) with the minority undergoing lumpectomy. All patients received some form of chemotherapy (26.2% in the neoadjuvant setting and 74.4% adjuvant systemic therapy). Radiation therapy was used in 66% of patients in the post-operative setting. At a median follow-up of 3.5 years, 25 patients experienced some type of recurrence, with patterns of first recurrences as follows: 7 local, 1 regional, 9 distant, and 3 mixed local and distant. Eleven patients had ipsilateral breast tumor recurrence. The TLR9 staining range was similar as previously detected in the Finnish cohort. However, tumor TLR9 staining score was not significantly associated with local recurrence, disease-free survival, or overall survival. Sixty-six patients were included in our study and 43 patients had tissue evaluable for review. Median age at the time of diagnosis was 51 years. Most patients (n = 39, 86.7%) were early stage, and the majority were also node-negative (n = 30, 66.7%). The vast majority had infiltrating ductal carcinoma (n = 43, 89.6%). Most patients had mastectomy (n = 28, 60.9%) with the minority undergoing lumpectomy. All patients received some form of chemotherapy (26.2% in the neoadjuvant setting and 74.4% adjuvant systemic therapy). Radiation therapy was used in 66% of patients in the post-operative setting. At a median follow-up of 3.5 years, 25 patients experienced some type of recurrence, with patterns of first recurrences as follows: 7 local, 1 regional, 9 distant, and 3 mixed local and distant. Eleven patients had ipsilateral breast tumor recurrence. The TLR9 staining range was similar as previously detected in the Finnish cohort. However, tumor TLR9 staining score was not significantly associated with local recurrence, disease-free survival, or overall survival. ConclusionsUnlike the highly homogenous Finnish population, TLR9 status was not associated with outcome in this cohort of African-American females with TNBC. It is suspected that TNBC tumors of African-American females behave in a different biologic manner than other subgroups; thus, further research into TLR9 will be undertaken in multiple patient populations with TNBC. Although the study results are limited by low patient numbers, it appears elevated tumor TLR9 expression is not associated with freedom from relapse in African American patients with TNBC. Unlike the highly homogenous Finnish population, TLR9 status was not associated with outcome in this cohort of African-American females with TNBC. It is suspected that TNBC tumors of African-American females behave in a different biologic manner than other subgroups; thus, further research into TLR9 will be undertaken in multiple patient populations with TNBC. Although the study results are limited by low patient numbers, it appears elevated tumor TLR9 expression is not associated with freedom from relapse in African American patients with TNBC.