Prognostic significance of a new grading system of lymph node morphology after neoadjuvant radiochemotherapy for esophageal cancer

Abstract

Background: Along with primary tumor response, lymph node (LN) status after radiochemotherapy is one of the most important prognostic factors for advanced esophageal carcinoma. We investigated the influence of neoadjuvant radiochemotherapy on histomorphologic parameters of LNs.

Methods: One hundred ninety-two patients with esophageal carcinoma underwent surgery after preoperative radiochemotherapy. Response of primary tumor was graded as "minor" or "major." Two matched subgroups were chosen: 20 patients with minor response and 20 patients with major response. Histomorphologic criteria of LNs underwent univariate and multivariate analyses and correlated with tumor response and prognosis statistics.

Results: The LNs from 40 patients (N = 1276) were examined (median number of LNs per patient, 31). Of patients with minor response, 65% showed LN metastasis; of those with major response, 20% did so (p = 0.011). Major responders had significantly lower rates of capsular and central fibrosis and vascular transformation and had more sarcoidlike lesions. Logistic regression analysis did not distinguish these parameters between major and minor responders. The 5-year survival rate was 55% for major responders and 10% for minor responders (p = 0.025), 47% for patients with LN metastasis (LNM) and 18% for patients with LNM (p = 0.041). An optimal prognostic factor, LN morphologic grading, was defined as follows: low risk, no LNM and less than 3 LNs with central fibrosis; medium risk, no LNM and central fibrosis in 3 or more LNs or LNM with an LN ratio of less than 0.05; high risk, all other cases. The 5-year survival rate was 56%, 25%, and 0% for patients considered to have low, medium, and high risk, respectively, according to LN morphologic grading (p < 0.003). With the inclusion of this classification in the Cox regression analysis, no other factors showed prognostic relevance.

Conclusions: Grading of LN morphology after neoadjuvant radiochemotherapy is the most important prognostic factor for patients with esophageal cancer.