Reduction Of Nodal Micrometastases In Patients With Histological Node-Negative Esophageal Cancer After Neoadjuvant Treatment.

73 Background: Neoadjuvant chemoradiation (CRT) is important in the treatment ofesophageal cancer. Rationales are tumor-downstaging and elimination of micrometastases improving resectability and curability rate. In this study we evaluated the effect of neo-adjuvant CRT on nodal micrometastases (NMM) in pN0 esophageal cancer patients. Methods: From a prospective database, we selected a matched group of patients on cT-stage, histological type and treatment without (group 1) or with neo-adjuvant CRT (group 2). Patients were staged by EUS, PET-scan, CT-scan and EUS guided cytology. CRT was given in a randomized clinical trial and consisted of paclitaxel 50 mg/m2 and carboplatin AUC = 2 for 5 weeks and concurrent radiotherapy (41.4 Gy/23 frs). All patients (n = 19) underwent a curative intended transthoracic esophagectomy with extended 2-field nodal dissection. After reviewing routine pathological examination all tumors were confirmed as stage pN0. Four sections of every examined lymph node (n = 261) were made at different levels according to a sentinel node protocol and further analyzed immunohistochemically with anti-CK8/18 (CAM 5.2) to detect NMM. Results: Patients characteristics were equally distributed. All patients had a microscopically radical (R0) resection. In group 2 (n = 9) the response rate was 55% which was complete (CR) in 33%. The median number of resected nodes was comparable: 15 ± 6.5 and 15 ± 5.6 in both groups. Thirtheen of the 261 (5%) pN0 nodes in these 19 pts contained NMM. In group 1 (n = 10); 12 of the 136 (9%) examined pN0 lymph nodes were positive and in group 2 only one of the 125 (0.8%) examined pN0 nodes was positive (p = 0.003). NMM were found in 7 pts (70%) in group 1 and in only one patient (11%) in group 2 (p = 0.02). Interestingly, this last patient had responded well to CRT. Conclusions: Neo-adjuvant CRT seems to have a significant impact on the numbers of NMMs in esophageal cancer. Based on the presence of NMM even in patients with good responses, we still advocate a curatively intended nodal dissection. No significant financial relationships to disclose.