Impact of the number of postoperative pathological lymph node metastasis areas on prognosis of thoracic esophageal squamous cell carcinoma / 国际肿瘤学杂志

ABSTRACT

Objective:To explore the impact of the number of pathological lymph node metastasis areas on the prognosis of patients with thoracic esophageal squamous cell carcinoma (ESCC) after radical surgery.Methods:The clinicopathologic data of 153 patients with ESCC treated by radical surgery at the Department of Thoracic Surgery of the Affiliated Taixing People′s Hospital of Yangzhou University from January 2012 to December 2014 were retrospectively analyzed. Among these patients, 76 had no adjuvant therapy, and 77 received adjuvant radiotherapy or chemoradiotherapy after surgery. According to the lymph node classification criteria of American Thoracic Association and the number of pathological lymph node metastasis areas, the patients were divided into non-regional lymph node metastasis group ( n=68), oligo-regional lymph node metastasis group (1-2 regional lymph node metastasis, n=54) and multi-regional lymph node metastasis group (≥3 regional lymph node metastasis, n=31). Kaplan-Meier method was used to calculate survival rate and survival comparison was performed by log-rank test. The Cox proportional hazards model was used to analyze prognostic factors, receiver operating characteristic (ROC) curve was used to analyze the predictive value of the number of lymph node metastasis areas. Results:The median overall survival (OS) was 37.0 months for the 153 patients, and the 1-, 3- and 5-year OS rates were 97.4%, 51.0% and 30.7% respectively. In the non-regional lymph node metastasis group, the median OS was 46.0 months, and the 1-, 3- and 5-year OS rates were 97.1%, 58.8% and 39.7% separately. In the oligo-regional lymph node metastasis group, the median OS was 39.0 months, and the 1-, 3- and 5-year OS rates were 94.4%, 55.6% and 35.2% respectively. In the multi-regional lymph node metastasis group, the median OS was 26.0 months, and the 1-, 3- and 5-year OS rates were 98.1%, 25.8% and 3.2% separately. There was a statistically significant difference among the three groups ( χ2=18.257, P<0.001). Among the 76 patients without adjuvant treatment, the 1-, 3- and 5-year OS rates were 94.7%, 50.0% and 34.2% in patients with non-regional lymph node metastasis, 90.9%, 36.4% and 9.1% in patients with oligo-regional lymph node metastasis, 97.4%, 18.8% and 0 in patients with multi-regional lymph node metastasis, and there was a statistically significant difference ( χ2=8.201, P=0.017). Among the 77 patients with adjuvant therapy, the 1-, 3- and 5-year OS rates were 97.7%, 66.7% and 46.7% in patients with non-regional lymph node metastasis, 96.9%, 68.8% and 53.1% in patients with oligo-regional lymph node metastasis, 93.3%, 26.7% and 6.7% in patients with multi-regional lymph node metastasis, and there was a statistically significant difference ( χ2=18.083, P<0.001). Univariate analysis showed that age ( HR=1.534, 95% CI 1.041-2.260, P=0.030), T stage ( HR=1.757, 95% CI 1.197-2.579, P=0.004), N stage ( HR=1.548, 95% CI 1.043-2.297, P=0.030), TNM stage ( HR=1.392, 95% CI 1.114-2.459, P=0.015), adjuvant therapy ( HR=0.545, 95% CI 0.370-0.803, P=0.002) and number of lymph node metastasis areas (multi-regional lymph node metastasis versus non-regional lymph node metastasis HR=0.385, 95% CI 0.238-0.624, P<0.001; multi-regional lymph node metastasis versus oligo-regional lymph node metastasis HR=0.442, 95% CI 0.269-0.726, P=0.001) were closely related to OS in patients with ESCC after operation. Multivariate analysis showed that T stage ( HR=1.699, 95% CI 1.143-2.525, P=0.009), adjuvant therapy ( HR=0.577, 95% CI 0.386-0.864, P=0.008) and number of lymph node metastasis areas (multi-regional lymph node metastasis versus non-regional lymph node metastasis HR=0.553, 95% CI 0.411-0.996, P=0.011; multi-regional lymph node metastasis versus oligo-regional lymph node metastasis HR=0.550, 95% CI 0.328-0.924, P=0.024) were independent prognostic factors for OS. The number of lymph node metastasis areas (AUC=0.648, 95% CI 0.560-0.735, P=0.004) was better than the number of lymph node metastasis (AUC=0.595, 95% CI 0.497-0.694, P=0.061) in predicting OS of patients with ESCC after radical surgery. Conclusion:The number of postoperative pathological lymph node metastasis areas in thoracic ESCC has important value in predicting survival prognosis, and adjuvant therapy can significantly improve the OS of patients with oligo-regional lymph node metastasis.