The present study analyzed the expression of PKC-ζ in individuals with no tumor complications and malignant female human breast tissue samples (lobular carcinoma <i>in situ</i>, invasive lobular carcinoma, ductal carcinoma <i>in situ</i> and invasive ductal carcinoma) with the use of western blot analysis, immunohistochemistry and statistical analysis (83 samples).
PKCζ expression was increased in malignant tissues compared with adjacent normal lung tissues and was associated with lymph node metastasis (P<0.05), although it was not associated with any other clinicopathological parameters, including sex, age, tumor size, smoking status or distant metastases (all P>0.05).
Interestingly, an increase of PKCζ expression was associated with the elevated tumor grade (P=0.04), but no such association was found in TNM stage (P=0.13).