Prognostic value of proliferating cell nuclear antigen (PCNA) in infiltrating ductal carcinoma breast

To assess the independent and interdependent prognostic value of proliferating cell nuclear antigen (PCNA) in carcinoma of breast in our female population and its association with pathologic variables and disease outcome.

A descriptive study.

Section of Histopathology, Department of Pathology and Microbiology, The Aga Khan University, Karachi from January 1992 to December 1997.

All cases diagnosed with invasive ductal carcinomas (IDC) of breast with lymph nodes sampling were included. The expression of PCNA was analyzed on tumor specimens of IDC breast. These patients also had axillary lymph node sampling. The expression of PCNA protein was analyzed immunohistochemically by PAP technique. Patients were followed for a median duration of 48 months.

The percentage of PCNA positive tumor cells was estimated semi-quantitatively. Positivity was seen in every case, mean PCNA positivity was 27% (range 10-80) with a median of 28%. The <25% positivity was seen in 149 (47%) cases, and >25% positivity seen in 166 (53%) cases. According to the pathological grading lowest mean PCNA was seen in grade-I i.e., 26% tumor cells showed nuclear reactivity to PCNA followed by grade-II 30% and grade-III 33%. PCNA categorical expression was significantly correlated with histological differentiation, (p<0.05) and tumor size (p<0.01). Distant metastases were seen in>25% positive cases (p<0.05). PCNA expression when correlated with overall survival, showed significant correlation between categorical PCNA (p<0.05). At a median follow-up of 48 months, 66% of <25 PCNA positive patients died with an overall survival of 3.16 years and disease-free survival of 2.5 years, among >25% PCNA positive patients 77% died with an overall survival of 2.7 years and a disease-free survival of 2.2 years.

In this study PCNA proved to be an independent prognostic indicator in predicting disease-free and overall survival in breast carcinoma patients.