PDCD4 as a Predictor of Sensitivity to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Patients

Objective: The purpose of this study was to examine the role of programmed cell death 4 (PDCD4) expressionin predicting tumor response to neoadjuvant chemoradiotherapy and outcomes for patients with locally advancedrectal cancer.
Methods: Clinicopathological factors and expression of PDCD4 were evaluated in 92 patientswith LARC treated with nCRT. After the completion of therapy, 4 cases achieved clinical complete response(cCR), and thus the remaining 88 patients underwent a standardized total mesorectal excision procedure.There were 38 patients (41.3%) with a good response (TRG 3-4) and 54 (58.7%) with a poor one (TRG 0-2).
Results: Immunohistochemical staining analyses showed that patients with high expression of PDCD4 were moresensitive to nCRT than those with low PDCD4 expression (P=0.02). High PDCD4 expression before nCRT andgood response (TRG3-4) were significantly associated with improved 5-year disease-free survival and 5-yearoverall survival (P<0.05). Multivariate analysis demonstrated that the pretreatment PDCD4 expression was anindependent prognostic factor.
Conclusion: Our study demonstrated that high expression of PDCD4 protein isa useful predictive factor for good tumor response to nCRT and good outcomes in patients with LARC.