The pattern of cervical lymph node metastasis in thoracic esophageal squamous cell carcinoma may affect the target decision for definitive radiotherapy

Background: Metastasis to lymph nodes is a key determinant of thoracic esophageal squamous cell carcinoma (TE-SCC) prognosis. We sought to identify factors linked with cervical lymph node metastasis, which could be used to inform the decision of surgical and definitive radiotherapy.

Methods: We retrospectively reviewed records from 1715 patients who had had radical esophagectomy with three-field lymphadenectomy between January 1993 and March 2007 in our hospital. All patients included in the study had pathologically confirmed TE-SCC and no clinical evidence of cervical metastasis.

Results: Cervical node metastases were found in 547 patients (31.9%); rates of cervical-node positivity were 44.2% for those with upper-thoracic tumors, 31.5% for mid-thoracic tumors, and 14.4% for lower-thoracic tumors. Univariate analysis showed that cervical node metastasis was associated with tumor site, differentiation, and length, pathologic T status, and pN status (P<0.05); however, only tumor site and pN status retained significance in multivariate analysis (P<0.05). Positive cervical nodes were most often found in the paraesophageal region (72.3%), followed by supraclavicular (24.4%); involvement of deep cervical (2.4%) or retropharyngeal nodes (0.9%) was rare (P<0.0001). Positive cervical nodes were most often associated with upper TE-SCCs (60.1%), followed by middle TE-SCCs (31.2%) and lower TE-SCCs (10.6%).

Conclusions: Upper TE-SCC with multiple involved nodes at any site was associated with a high rate of cervical node metastasis. These findings provide critical information for clinical decision-making regarding the extent of nodal dissection or the size of radiation fields in definitive radiotherapy.