cN + patients with low GDF15 expression benefitted from induction TPF in overall survival ( P = 0.039 , HR = 0.247 ) and DMFS ( P = 0.039 , HR = 0.247 ) , cN - patients with high GDF15 expression benefitted from induction TPF in overall survival ( P = 0.019 , HR = 0.231 ) , disease-free survival ( P = 0.011 , HR = 0.281 ) , locoregional recurrence-free survival ( P = 0.035 , HR = 0.347 ) and DMFS ( P = 0.009 , HR = 0.197 ) .