Clinical outcomes and benefits for staging of surgical lymph node mapping after esophagectomy

Dissection of lymph nodes (LN) immediately after esophagectomy is utilized by some surgeons to aid determination of LN stations involved in esophageal cancer. Some suggest that this increases LN yield and gives information regarding the pattern of lymphatic spread, others feel that this may compromise a circumferential resection margin (CRM) assessment. The aim of this study is to evaluate the effect of ex vivo dissection on the assessment of the CRM and the pattern of lymph node dissemination in patients with adenocarcinoma of the esophagus and gastroesophageal junction (GEJ) undergoing radical surgery after neoadjuvant chemotherapy and their prognostic impact. Data from consecutive patients with potentially curable adenocarcinoma of the distal esophagus and GEJ who received neoadjuvant treatment followed by surgery were analyzed. Clinical and pathological findings were reviewed and LN burden and location correlated with clinical outcome. Pathology specimens were dissected into individual LN groups 'ex-vivo' by the surgeon. A total of 301 patients were included: 295 had a radical proximal and distal resection margin however in 62(20.6%) CRM could not be assessed. A median of 33(10-77) nodes were recovered. A 117(38.9%) patients were ypN0 while 184(61.1%) were LN positive (ypN1-N3). LN stations close to the tumor were most frequently involved. Twenty-seven (14.7%) patients had only thoracic stations involved, 48(26.1%) only abdominal stations and 109 (59.2%) had both. Median survival for yN0 patients was 171 months compared to 24 months for those LN positive (P< 0.001). Multivariate analyses identified ypT-category, ypN-category, male gender, and nonradical resection (proximal or distal) margin as significant prognostic factors. Surgical dissection of nodes after esophagectomy enables accurate LN assessment, but may compromise CRM assessment in up to 20% of cases. It also provides valuable information regarding the pattern of nodal spread.