The infiltration of immune cells, such as tumour infiltrating neutrophils (TINs), into the tumour microenvironment is known to be an activator and regulator of tumour immunity. Offering a complex pathological picture, these infiltrates are known to be associated with a better response to chemotherapy in colorectal cancer, whilst also being associated with worse clinical outcomes in other malignancies, such as renal cell carcinoma. Furthermore, the role of TINs in breast cancer (BC) is less well understood. Although the presence of TINs in a BC setting has been associated with worse prognosis, the dynamic change on TIN concentration before and after treatment with neoadjuvant chemotherapy (NACT) in relation to prognosis has not yet been determined.
With results recently published in BMC Cancer, Geng et al., retrospectively investigated this association by enrolling 133 women with BC who underwent NACT before surgery between 2004 and 2017. The efficacy of NACT was assessed using RECIST criteria, with immunohistopathological staining for CD66b occurring after surgery. Patients in complete or partial response (CR), (PR) were categorised into a remission group, whilst those who achieved stable or progressive disease (SD), (PD) were categorised into a non-remission group. Dynamic TIL change was assessed by splitting patients into low and high difference groups, based on TIL values before and after NACT, and subsequently compared to clinical outcomes. Follow-up then occurred for all patients every 3 months for the 1st year post-surgery and every 6 months thereafter.
The median age of enrolled patients was 54 years old. 88 patients were hormone receptor positive (HR+), 17 were human epidermal receptor positive (HER+), and 28 had triple negative breast cancer (TNBC). At a median follow-up of 27 months, patients with higher TINs were more likely to have resistance to treatment, after treatment with NACT (P < 0.001). Additionally, higher TINs after NACT were associated with a significantly shorter DFS (HR[95%CI]: 3.415[1.489-7.831], P= 0.002). Interestingly, a lower change in TINs before and after NACT was associated with higher rates of recurrence and lower rates of remission and was found to be a significant predictor of DFS (HR[95%CI]: 0.984[0.974-0.994], P= 0.002).
These results clearly demonstrate that BC patients with a higher TIN after NACT have worse clinical outcomes, indicating TIN concentration as a prognostic indicator in this setting. Furthermore, this is the first study to demonstrate that a higher dynamic change in TIN before and after NACT is associated with better prognosis.
Geng SK et al., Tumour infiltrating neutrophil might play a major role in predicting the clinical outcome of breast cancer patietns trrated with neoadjuvant chemotherapy. BMC cancer 2021; 21(68). [epub].