Node metastatic and prognostic analysis of superficial thoracic esophageal squamous cell carcinoma with T1 status

Abstract

Objective To investigate the pattern of lymph node metastasis and the long-term survival in patients with superficial thoracic esophageal squamous cell carcinoma(ESCC) with T1 status. Methods 176 patients with pathologically confirmed superficial ESCC with T1 status who underwent Mckeown esophagectomy between January 1999 and January 2010 were retrospectively enrolled. Tumor invasion is classified according to the Japanese Association of esophageal cancer classification standard. Epithelial layer and mucosa(m) divided into epithelial layer(M1), lamina propria mucosa(M2), muscularis mucosa(M3), submucosa(M3). Submucosa(Tsm) were average divided into submucous upper 1/3(SM1), middle 1/3(SM2) and lower 1/3(SM3). Node metastatic pattern of different tumor invasion and the prognostic indication is investigated. Results The rate of node metastasis in patients with SM invasion is significantly higher than those with m invasion(28.2% vs. 4.4%, P=0.001); the 5-year survival rate of patients with SM invasion is significantly higher than those with m invasion(91.4%vs. 75.8%, P=0.048). The rate of node metastasis in patients with M1, M2, and M3 invasion is 0, 0, and 6.2%, respectively; the rate of node metastasis in patients with SM1, SM2, and SM3 invasion is 20.0%, 29.4%, and 33.3%, respectively, with the 5-year survival rate of 86.5%, 77.4%, and 67.3%, respectively.The highest rate of lymph node metastasis in the neck region, mainly in the right cervical paraesophageal lymph nodes(101R). The rate of cervical lymph node metastasis in patients with SM1, SM2, and SM3 invasion is 15.0%, 20.6% and 24.6%, respectively.The rate of 101R metastasis in patients with SM1, SM2, and SM3 invasion is 10%, 8.8% and 24.6%, respectively.Univariate analysis showed that there is no significant difference between lymph node metastasis rate and patient age, gender, tumor differentiation and tumor location, and vascular invasion and tumor invasion depth(m1-3/SM1-3) difference is statistically significant.Nodal status is proved as the independent prognostic factor(HR=2.127, 95%CI=1.219-3.713). The 5-year survival of patients with and without node metastasis is 64.7% and 83.5%(P=0.005). Conclusion The rate of node metastasis of SM invasion cohort is significantly higher than M invasion cohort. There was no significant difference in lymph node metastasis rate between SM1, SM2 and SM3.Lymph node metastasis(N staging) is an independent prognostic factor for stage T1 thoracic ESCC. Compared with the thoracic and abdominal lymph nodes, the cervical lymph node metastasis rate is higher, and concentrated in 101R. Key words: Esophageal cancer; lymph node metastasis; Survival analysis