Oncological recurrence following pathological complete response after neoadjuvant treatment in patients with...

To evaluate recurrence in patients with post-neoadjuvant pathological complete response (pCR) and in patients with complete response of primary tumor but persisting lymphatic spread of disease (non-pCR, ypT0ypN +) of esophageal cancer.

Seventy-five patients (63 pCR, 12 non-pCR) were analyzed retrospectively. Pattern and incidence of local and distant recurrence as well as the impact on overall (OS) and disease-free survival (DFS) were evaluated. The efficacy of neoadjuvant chemotherapy according to FLOT protocol was compared to neoadjuvant chemoradiation according to CROSS protocol.

In the pCR group, isolated local recurrence was diagnosed in 3%, while no isolated local recurrence was observed in the non-pCR group due to the high incidence of distant recurrence. Distant recurrence was most common in both cohorts (isolated distant recurrence: pCR group 10% to non-pCR group 55%; simultaneous distant and local recurrence: pCR group 3% to non-pCR group 18%). Median time to distant recurrence was 5.5 months, and median time to local recurrence was 8.0 months. Cumulative incidence of distant recurrence (with and without simultaneous local recurrence) was 16% (± 6%) in pCR patients and 79% (± 13%) in non-pCR patients (hazard ratio (HR) 0.123) estimated by Kaplan-Meier method. OS (HR 0.231) and DFS (HR 0.226) were significantly improved in patients with pCR compared to patients with non-pCR. Advantages for FLOT protocol compared to CROSS protocol, especially with regard to distant control of disease (HR 0.278), were observed (OS (HR 0.361), DFS (HR 0.226)).

Distant recurrence is the predominant site of treatment failure in patients with pCR and non-pCR grade 1a regression, whereby recurrence rates are much higher in patients with non-pCR.