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Lymph node metastases of adenocarcinoma of the esophagus and esophagogastric junction.

BACKGROUND
Esophageal adenocarcinoma is becoming an increasingly important problem. It has been the most rapidly increasing malignancy in western countries in the last decades, and its prognosis is poor. The aim of this study was to evaluate the relationship between tumor invasion depth and lymph node metastasis for adenocarcinoma of the esophagus and esophagogastric junction, and to analyze the impact of lymph node metastases on survival of the patients.


METHODS
The study group comprised 121 patients with adenocarcinoma of the esophagus or esophagogastric junction, who underwent esophagectomy between January 1985 and December 2003 at either the Royal Adelaide Hospital or the Flinders Medical Center, Australia. Overall, there were 101 males and 20 females, with a mean age at surgery of 62 years (range 36 - 80). All of them were followed up for 6 months to 13 years (mean, 6.5 years). The relationship between tumor invasion depth and lymph node metastasis, as well as between survival and lymph node metastasis in these patients were analyzed by Chi-square or Fisher's exact test. A P < 0.05 was considered statistically significant.


RESULTS
The tumors were located entirely within the esophagus in 83 patients, and involved the gastro-esophageal junction in 38. The overall resection rate was 96.7% (117/121). When tumor invasion was within mucosa or submucosa of the esophagus (T1), the lymph node metastasis rate was 22.2% (10/45), the mean number of metastatic lymph nodes was 0.3, and the proportion of more than 4 lymph nodes metastases was 0% (0/45). When tumor invaded the adjacent structures of the esophagus (T4), the lymph node metastasis rate was 85.7% (6/7); the mean number of metastatic lymph nodes was 5.1, and the proportion of more than 4 lymph nodes metastases was 71.4% (5/7). There was a significant difference between T1 and T4 (P < 0.01). The 5-year survival rate for patients without lymph node metastasis was 52.9%, for those with 1 - 4 nodes involved was 11.5%, and for patients with more than 4 positive nodes was 0.0% (P < 0.01).


CONCLUSIONS
There is a close association between tumor invasion depth and lymph node metastasis for adenocarcinoma of the esophagus and esophagogastric junction. Both the number and rate of lymph node metastasis are significantly correlated to the depth of tumor invasion. Moreover, when the tumor invades deeper into the esophageal wall, the percentage of patients with more than 4 involved nodes increases. Both the lymph node status and the number of metastatic nodes are important prognostic factors for the disease.