Predictive Value of Postoperative Peripheral CD4+ T Cells Percentage in Stage I-III Colorectal Cancer: A Retrospective Multicenter Cohort Study of 1028 Subjects

Background: Association of postoperative peripheral CD4+ T cells percentage and recurrence in colorectal cancer(CRC) remains to be explored. Therefore, we aimed to investigate the association between the postoperative peripheral CD4+ T cells percentage and recurrence in CRC patients.  Patients and Methods: Consecutive stage I-III CRC patients without neoadjuvant treatment undergoing curative resection from January 2010 to July 2016 were identified in two Chinese centers. The association between the postoperative CD4+ T cells percentage, measured within 12 weeks after surgery, and recurrence-free survival (RFS) was analyzed. Results: A total of 1028 patients were identified (training set: 913 patients, validation set: 115 patients). In the training set, the 5-year RFS rate of the 441 patients with abnormal postoperative CD4+ T cells percentage was significantly lower than that of those with normal percentage (70.3%[95 %CI 65.7%–75.2%] vs. 77.6%[95%CI 73.7%–81.7%]; unadjusted hazard ratio[HR] 1.36[95%CI 1.04–1.78], P=0.02). The result was confirmed in the validation set. Multivariable Cox regression analysis demonstrated that the association of postoperative CD4+ T cells percentage with 5-year RFS was independent both in the training and validation sets. In propensity score matching analysis, patients with normal postoperative CD4+ T cells percentage were found to have a favourable response to adjuvant chemotherapy (HR 0.29 [95% CI 0.12–0.72], P=0.008). Conclusion: Postoperative peripheral CD4+ T cells percentage is a predictive biomarker for RFS in patients with CRC, which can identify those who will benefit from adjuvant chemotherapy. Funding Statement: This work was supported by grants from the National Key Research and Development Program of China [2017YFC1309100], the National Natural Scientific Foundation of China [81771912], and the Applied Basic Research Projects of Yunnan Province, China [2018FE001- 065 and 2018FE001-251]. Declaration of Interests: The authors declare that they have no potential conflicts of interest. Ethics Approval Statement: This retrospective study was approved by the institutional review board of each participating hospital. The requirement for informed consent was waived by the board, owing to the study's retrospective nature. All the patient data in the survey were anonymized.