Utilizing peripheral blood inflammatory biomarker (PBIB) to predict response to systemic therapy in patients with breast cancer.

BACKGROUND: Inflammation is a recognized factor in cancer progression and resistance to treatments. Several studies correlated inflammation-related peripheral blood inflammatory biomarkers (PBIB) to disease progression and poor survival in various cancer types and different populations. Nonetheless, inflammation is affected by the distinctive characteristics and environmental exposure of each population. There is no prior study addressing the association of pre-treatment inflammatory markers with outcomes in patients with breast cancer (BC) from Saudi Arabia. In this study, we evaluated the prognosis of locally advanced breast cancer (LABC) in relation to several PBIB.

MATERIALS AND METHODS: We retrospectively analyzed the data of female patients with LABC undergoing neoadjuvant chemotherapy (NACT). Demographics, body mass index (BMI), clinicopathologic characteristics and stage of the tumor, follow-up status, and response to treatment were collected. Outcomes were evaluated in relation to pre-treatment peripheral blood indices that were grouped based on the local laboratory cutoff values. Objective response rate (ORR) was predefined and assessed according to the post-NACT magnetic resonance imaging (MRI) breast and subcategorized into complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD).

RESULTS: A total of 172 female patients with BC met the eligibility criteria from January 2014 to December 2019. The mean age at diagnosis was 53.4 ± 11, and BMI was 31.2 ± 6. Left BC accounted for 54.7%, and the majority was invasive ductal carcinoma (85.5%), moderately differentiated (51%), stage III (AJCC 8th edition) (73%), and estrogen receptor (ER)-positive tumor (79.1%). Human epidermal growth factor receptor 2 (HER2)-positive BC was reported in 32% and triple-negative breast cancer (TNBC) in 10%. Radiologic CR accounted for the majority of ORR (71.5%). Higher percentage of patients with normal red cell distribution width (RDW) of red blood cell (RBC) and low neutrophil-lymphocyte ratio (NLR) had CR with a significant P value of 0.003 and 0.014, respectively.

CONCLUSION: Among several peripheral blood indices, RDW and NLR significantly influenced ORR. They can be explored further to potentially predict response after systemic therapy in patients with LABC. The great advantage of these biomarkers stems from their availability and affordability in routine clinical practice.