Researchers examined lymphatic spread in esophageal cancer by routine histopathology and by immunohistochemistry.
A total of 1,584 resected lymph nodes were obtained from 86 patients with resected esophageal carcinoma and evaluated by routine histopathology.
In addition, frozen tissue sections of 540 lymph nodes classified as tumor-free by routine histopathology were screened for micrometastases by immunohistochemistry with the monoclonal antibody Ber-EP4.
|Presence of micrometastases associated with decreased survival|
|Journal of Clinical Oncology|
The lymph nodes were mapped according to the mapping scheme of the American Thoracic Society modified by Casson et al.
The researchers found that 44 patients (51%) had pN1 disease, and 61 patients (71%) harbored lymphatic micrometastases detected by immunohistochemistry.
Skip metastases detected by routine histopathology were present in 34% of pN1 patients. Skipping of micrometastases detected by immunohistochemistry was found in 66%.
The presence of micrometastases was found to be associated with a significantly decreased relapse-free and overall survival (56.0 vs.10.0 months and > 64 vs.15 months).
Cox regression analysis revealed the independent prognostic influence of micrometastases in lymph nodes. Lymph node skipping had no significant independent prognostic influence on survival.
Author Stefan B. Hosch, of the University of Hamburg, said on behalf of the team, "Histopathologically and immunohistochemically detectable skip metastases are a frequent event in esophageal cancer."
"Only extensive lymph node sampling, in conjunction with immunohistochemical evaluation, will lead to accurate staging.
"An improved staging system is essential for more individualized adjuvant therapy," he concluded.