Predictive Significance of Systemic Immune-Inflammation Index in Patients with Breast Cancer: A Retrospective Cohort Study

Abstract

Background

Peripheral blood inflammation indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), have become research hotspots in the diagnosis, treatment, and prognosis prediction of breast cancer, whereas existing research findings remain controversial.

Methods

Data pertaining to 1808 breast cancer patients were collected retrospectively to analyze the predictive value of NLR/PLR/SII for breast cancer clinicopathological characteristics, chemotherapy response, and relapse. 1489, 258, and 53 eligible breast cancer patients entered into the three analyses, respectively. Logistic regression analyses were used to assess the correlation between these indices and poor response to chemotherapy. A predictive scoring model was established to predict chemotherapeutic responses based upon the odds ratio values of significant variables identified in logistic regression analyses.

Results

Higher pretherapeutic NLR/PLR/SII values were significantly correlated with higher tumor stage, triple-negative breast cancer, premenopausal status, and younger age. Logistic regression analyses indicated that pretherapeutic high SII (as a continuous variable or with a cut-off value of 586.40) and HER2-negative status were independent predictors of poor response to neoadjuvant chemotherapy. A first-in-class SII-based predictive scoring model well distinguished patients who might not benefit from neoadjuvant chemotherapy, with an area under the curve of 0.751. In HR-positive cancers, SII was more strongly associated with clinicopathological features and chemotherapy response. In addition, a receiver operating characteristic curve analysis indicated that the specificity of follow-up SII in identifying cancer relapse was greater than 98.0% at a cut-off value of 900.

Conclusion

As a predictor of breast cancer, especially in the HR-positive subtype, SII may eclipse NLR/PLR. SII-high patients are more likely to have a worse chemotherapy response and a higher risk of recurrence.

Keywords:

• breast cancer
• neutrophil-to-lymphocyte ratio
• platelet-to-lymphocyte ratio
• systemic immune-inflammation index
• chemotherapy response
• predictor

Abbreviations

AJCC, American Joint Committee on Cancer; AUC, area under the curve; BMI, body mass index; CI, confidence interval; ER, estrogen receptor; HER2, human epidermal growth factor receptor-2; HR, hormone receptor; IDC, invasive ductal carcinoma; IL, interleukin; ILC, invasive lobular carcinoma; IQR, interquartile range; LVI, lymphovascular invasion; MP, Miller-Payne; NLR, neutrophil-to-lymphocyte Ratio; OR, odds ratio; pCR, pathological complete response; PLR, platelet-to-lymphocyte ratio; PLT, platelet; PR, progesterone receptor; ROC, receiver operating characteristic; ROS, reactive oxygen species; SII, systemic immune-inflammation index; TNBC, triple-negative breast cancer.

Data Sharing Statement

The data used to support the findings of this study are included within the article.

Ethics Approval and Consent to Participate

This study was reviewed and approved by Institutional Review Board of the Second Affiliated Hospital of Zhejiang University School of Medicine (ethical approval NO. 2021-0295), which waived the informed consent requirement due to the retrospective design of the study. This study complied with the Declaration of Helsinki. The patient data was maintained with confidentiality.

Acknowledgments

The authors wish to thank all patients who participated in this study.

Disclosure

The authors declare that there are no conflicts of interest.

Additional information

Funding

This work was funded by Natural Science Foundation of Zhejiang Province (LQ19H160045).