PTGS2 and digestive system neoplasm: Table-2 illustrates that higher levels of COX-2 expression were associated with higher T-stage (p = 0.008), higher N-stage (p = 0.049), poorly differentiated tumour on histology (p = 0.045) and higher incidence of tumour recurrence (p = 0.01) after potentially curative resection of adenocarcinoma of oesophagus.