Prognostic significance of pathologically detected extramural venous invasion (EMVI) in rectal carcinoma

Abstract

Background: Rectal carcinoma (RC), a common malignancy of the gastrointesƟ nal tract, remains a great clinical challenge due to the increased risk of local and/or systemic recurrence. The mechanism of primary tumor progression and disseminaƟ on may be the crucial prognosƟ c factor. Direct vascular spread, especially venous invasion, has been previously recognized and validated as an important predictor of adverse prognosis. Extramural venous invasion (EMVI) is characterized by the presence of tumor cells within veins outside the bowel wall and is strongly associated with poor survival, increased risk of local recurrence, systemic recurrence, and death. The aim of this study is to examine the prognosƟ c value of pathologically detected EMVI and its relaƟ onship with other available clinicopathological parameters of paƟ ents with RC. PaƟ ents and Methods: This retrospecƟ ve study included 100 untreated and non-metastaƟ c RC paƟ ents (50 EMVI+ and 50 EMVI-) who underwent curaƟ ve resecƟ on between January 2016 and June 2018 and were followed for the next fi ve years (median follow-up of 71.1 months). The presence of EMVI was assessed on standard hematoxylin and eosin-stained histolological secƟ ons of postoperaƟ ve tumor specimens samples, confi rmed by a consultant pathologist in arbitrary cases, and in accordance with validated College of American Pathologist (CAP) guidelines. Results: The presence of EMVI within a selected cohort of RC paƟ ents signifi cantly associated with female gender (p=0.039), T4 stage (p=<0.001), N2 stage (p=<0.001), less number (n≤3) of involved lymph nodes (p=<0.001), excessive lymphaƟ c infi ltraƟ on (p=0.044), presence of perineural invasion (p=0.002), posiƟ ve circumferenƟ al margin (CRM) (p=0.003), and TNMIII stage (p=<0.001). In addiƟ on, within EMVI+ paƟ ents, metastases, dominantly in the liver (13/19, 68%), and death outcomes were more frequent events (p=0.013 and p=0.032, respecƟ vely), while survival analyses revealed that EMVI+ paƟ ents had signifi cantly shorter overall survival (OS, p=0.035) and disease-free survival (DFS, p=0.030). Conclusion: Obtained results strongly suggest that the EMVI type of vascular invasion, considered independently of classical stage parameters and separately from lymphaƟ c invasion, has the potenƟ al to be a reliable predictor of the course and outcome of the disease, which should be confi rmed on a larger cohort of paƟ ents with RC.