A series of 80 female patients undergoing surgery for primary breast
ductal infiltrating carcinoma not otherwise specified (NOS) was
immunohistochemically studied in order to verify any relationships
between Proliferating Cell Nulear Antigen (PCNA) immunostaining, Heat
Shock Protein 70 (HSP70) immunoreactivity, and several
clinicopathological predictors.
Positive PCNA scores (> 20% of strongly immunopositive malignant
nuclei) were observed in neoplastic cells’ nuclei in 13 tumors (16.25%)
and were intimately associated with axillary nodal involvement (p =
0.0131), relatively high tumor grades (p = 0.0016), increased tumor size
(p = 0.0312), and low or negative levels of estrogen receptors (p =
0.0323). HSP70 positive immunoexpression in malignant cells’ cytoplasm
(percentage of HSP70 immunoreactive cells > 10%) was detected in 33
samples (41.25%). It correlated significantly with presence of axillary
lymph nodal metastases (p = 0.0033) and rather poor tumor
differentiation (p = 0.0014), whereas an association of borderline
statistical significance emerged between HSP70 immunoreactivity and high
progesterone receptor status (p = 0.0637).
PCNA positive immunostaining demonstrates the tumors’ proliferative
fraction and might be used as an indicator of increased malignant
potential in breast cancer since it was associated with four adverse
prognosticators. HSP70 immunodetection is a probable marker of the
biological stress experienced by breast cancer cells, since it was
related to relatively high tumor grades. Since both proteins may
potentially predict disease outcome, their prognostic significance must
be validated by direct relation to survival. A multivariate statistical
analysis including the variables with which both proteins were
associated will reveal any possible independent prognostic value of PCNA
and HSP70 immunostaining in local, ductal invasive breast cancer NOS