Poorer prognosis associated with simultaneous lymphatic and vascular invasion in patients with squamous carcinoma of the thoracic oesophagus

OBJECTIVES: The objective of this study was to demonstrate the cumulative influence of simultaneous lymphatic and vascular invasion in thoracic oesophageal squamous carcinoma after radical operation. METHODS: A total of 598 cases with thoracic oesophageal squamous carcinoma that were cured by radical open oesophagectomy and extensive lymphadenectomy in the period of 2002 to 2014 were included. An association of the status of lymphovascular invasion with clinicopathological factors and a recurrent pattern was illustrated. Overall survival and disease-free survival were calculated, and the risk factors for decreased disease-free survival were determined with Kaplan-Meier subset analyses and Cox regression analysis. RESULTS: The status of lymphovascular invasion was significantly associated with tumour differentiation (P = 0.045) and the pathological tumour, node and metastasis stage (P < 0.001), which includes the tumour intramural invasive depth (T parameter) as well as regional (N parameter) and distant (M parameter) lymph node involvement. The 1-, 3- and 5-year overall survival and postoperative disease-free survival were significantly decreased by lymphatic or vascular invasion alone (P < 0.001) and were further decreased by simultaneous lymphatic and vascular invasion (P < 0.001). The independent risk factors that predicted reduced disease-free survival were the following: T parameter (P < 0.001, odds ratio: 1.436), N parameter (P < 0.001, odds ratio: 1.838) and the status of lymphovascular invasion (P < 0.001, odds ratio: 1.568). Simultaneous lymphatic and vascular invasion were significantly correlated with postoperative early recurrence (P=0.037). CONCLUSIONS: Simultaneous lymphatic and vascular invasion independently has a more adverse effect on prognosis than lymphatic or vascular invasion alone. Differentiating between lymphatic and vascular invasion is recommended in order to further study the role of lymphovascular invasion in cancer staging and prognostication in multicentre prospective studies.