The tumour cystatin C level correlated inversely with pN-stage (pN0vs pN+: 18.4 vs 14.2 ng mgp−1, P=0.047), whereas a trend of lower cystatin C levels was observed in the group with extranodal tumour extention compared to that with no extranodal spread (14.0 vs 17.4 ng mgp−1, P=0.069). This evidence concerns the gene CST3 and neoplasm.