Cyclooxygenase-2 expression after preoperative chemoradiotherapy correlates with more frequent esophageal cancer recurrence

AIM： To investigate the relationship between cycloo- xygenase-2 （COX-2）, and vascular endothelial growth factor （VEGF）, and to determine the clinical significance of this relationship in esophageal cancer patients undergoing chemoradiotherapy （CRT）. METHODS： Immunohistochemical staining was used to evaluate COX-2 and VEGF expression in 40 patients with histologically-confirmed esophageal squamous carcinoma （ESCC） who were undergoing preoperative CRT. RESULTS： Fourteen out of 40 ESCC patients showed a pathological complete response （CR） after CRT. COX-2 and VEGF protein expressions were observed in the cytoplasm of 17 and 13 tumors, respectively, with null expression in 9 and 13 tumors, respectively. COX-2 expression was strongly correlated with VEGF expression （P 〈 0.05）. There were also significant associations between COX-2 expression, tumor recurrence, and lymph-node involvement （P = 0.0277 and P = 0.0095, respectively）. COX-2 expression and VEGF expression had significant prognostic value for disease-free survival （log-rank test; P = 0.0073 and P = 0.0341, respectively）, but not for overall survival, as assessed by univariate analysis. expression correlates with VEGF expression and might be a useful prognostic factor for more frequent tumor recurrence in ESCC patients undergoing neoadjuvant CRT. These findings support the use of anti-angiogenic COX-2 inhibitors in the treatment of ESCC.

Preoperative therapy in locally advanced esophageal cancer

Esophageal cancer is an aggressive malignancy associated with dismal treatment outcomes. Presence of two distinct histopathological types distinguishes it from other gastrointestinal tract malignancies. Surgery is the cornerstone of treatment in locally advanced esophageal cancer(T2 or greater or node positive); however, a high rate of disease recurrence(systemic and loco-regional) and poor survival justifies a continued search for optimal therapy. Various combinations of multimodality treatment(preoperative/perioperative, or postoperative; radiotherapy, chemotherapy, or chemoradiotherapy) are being explored to lower disease recurrence and improve survival. Preoperative therapy followed by surgery is presently considered the standard of care in resectable locally advanced esophageal cancer as postoperative treatment may not be feasible for all the patients due to the morbidity of esophagectomy and prolonged recovery time limiting the tolerance of patient. There are wide variations in the preoperative therapy practiced across the centres depending upon the institutional practices, availability of facilities and personal experiences. There is paucity of literature to standardize the preoperative therapy. Broadly, chemoradiotherapy is the preferred neo-adjuvant modality in western countries whereas chemotherapy alone is considered optimal in the far East. The present review highlights the significant studies to assist in opting for the best evidence based preoperative therapy(radiotherapy, chemotherapy or chemoradiotherapy) for locally advanced esophageal cancer.