Overexpression of SLPI correlated with different grades ( moderate or good differentiation : 2.7 % low expression versus 97.3 % high expression , low differentiation : 41.7 % low expression versus 58.3 % high expression ) , TNM stage ( I or II : 4.2 % low expression versus 95.8 % high expression ; III or IV : 19.7 % low expression versus 80.3 % high expression ) , lymphatic metastasis ( 18.6 % low expression versus 81.4 % high expression ) and distal metastasis ( 86.5 % low expression versus 13.5 % high expression ) , but not with patient age or sex ( P = 0.613 , P = 0.871 ) .