Análisis del contenido citosólico de la proteína pS2 en el cáncer de mama

Abstract

To analyze pS2 cytosolic levels in breast carcinomas and their correlation with different clinical characteristics of the patients and their tumours. Cytosolic pS2 levels were measured by radioimmunometric assay in tumours from 168 breast cancer patients. The pS2 values ranged from 0 to 251 ng/mg protein (mean SD: 21.8 38.1; median: 7.9 ng/mg protein). These protein levels were significantly (p < 0.05) higher in premenopausal patients (27.6 45.2) than in postmenopausal patients (19.5 33.8). Intratumour pS2 levels were also significantly (p < 0.05) correlated with histologic grade of the tumours, and were higher in well diferentiated tumours (grade I: 28.8 42.8) than in moderately differentiated tumours (grade II: 19.7 35.6) and than in poorly differentiated tumours (grade III: 18.9 37.3). Similarly, significant differences in pS2 content were found between positive estrogen receptor (ER) tumours and ER-negative tumours (29.1 46.5 vs 11.3 15.9, respectively; p<0.0001), as well as between positive progesterone receptor (PR) tumours and PR-negative tumours (29.1 49.8 vs 15.3 21.5, respectively; p < 0.05). The results suggest that pS2 may be a useful prognostic marker in breast cancer, and may also be useful to identify patients who are likely to benefit from hormone therapy.