Early response to neoadjuvant chemotherapy in advanced esophageal cancer evaluated by computed tomography predicts the utility of a second cycle of chemotherapy.

Multi-course neoadjuvant chemotherapy (NACT) followed by surgery is a promising treatment for advanced esophageal cancer. However, non-responders may continue to receive ineffective treatment, since there are no definitive criteria for early discontinuation of NACT. In this study, we analyzed 103 advanced esophageal cancer patients treated with 2 cycles of NACT followed by surgery. Patients with >20% decrease in the size of the primary tumor as evaluated by computed tomography (CT) following the first cycle of chemotherapy, were defined as early responders and the remainder as early non-responders. Clinicopathological factors and prognosis were compared between the 2 groups. The reduction rate of the second cycle and progression-free survival (PFS) of early non-responders were significantly worse than those of early responders (p=0.0001 and 0.0375, respectively). In addition, pathological T stage, pathological assessment of tumor regression and number of metastatic lymph nodes were significantly unfavorable in early non-responders (p=0.023, 0.007 and 0.0041, respectively). Among the clinical factors that were available prior to administration of the second cycle, clinical T3 stage and early non-responder status were the only independent unfavorable factors (p=0.028 and 0.0062, respectively). Patients with both unfavorable factors had a significantly poorer PFS compared to the remaining patients and a PFS similar to those who had both factors but received only 1 cycle of NACT. In conclusion, the reduction rate of the primary tumor as evaluated by CT following the first cycle of NACT, may aid physicians in determining whether to administer a second cycle. In early non-responders bearing T3 tumors, NACT should be discontinued after the first cycle.