Association of clinical biomarkers and response to neoadjuvant therapy in breast cancer

Introduction: Neoadjuvant therapy is an essential component of multimodality therapy for locally advanced breast adenocarcinoma (BC). Complete pathologic response (pCR) is a useful surrogate for long-term oncologic outcome. Aim: To assess the association between clinicopathologic, molecular and immunological markers and treatment response to neoadjuvant therapy in BC. Methods: BC patients undergoing neoadjuvant therapy were identified from a prospectively maintained institutional database. Serum haematological/biochemical values, histopathologic, immunohistochemical data and TNM stage were obtained from electronic records. Patients were categorised into complete responders vs non-complete responders and responders vs non-responders. Statistical analysis was performed via SPSS. Results: Overall, 299 BC patients were included. The average age was 49.8 ± 11.5 years. A pCR was evident in 22.6% (n = 69). pCR was associated with early T stage and non-luminal subtypes (HER2 enriched [HER2 +] and triple negative [TNBC]). The neutrophil–lymphocyte ratio (NLR) pre-operatively was lower in patients with a pCR (p = 0.02). The lymphocyte-CRP ratio (LCR) was also slightly reduced in responders (p = 0.049) at diagnosis. A pre-op NLR greater than 2 was not found to be a significant predictive factor (p = 0.071) on multivariable logistic regression analysis. T stage at diagnosis (p = 0.024), N stage (p = 0.001) and breast cancer subtype (p = 0.0001) were also determined to be significant predictive factors of complete response. Conclusion: pCR was more likely in patients with less advanced disease in BC. The presence of HER2 + or TNBC in BC also increases the likelihood of pCR. Neoadjuvant therapy stimulates the systemic inflammatory response; however, a reduced baseline NLR may be associated with increased pCR. Confirmation with larger datasets is required.