[Expression of pS2 protein in breast cancer and its relationship with estrogen and progesterone receptors].

BACKGROUND

We studied pS2 protein in breast tumors and its relation with estrogen and progesterone receptors and with anatomopathological characteristics of the tumors.

MATERIAL AND METHODS

We measured the pS2 content (by IRMA) and steroid receptors content (by EIA) in 151 breast tumors. Results were compared and correlated with tumoral characteristics.

RESULTS

53% of tumors were pS2+. Among them, 91% were estrogen receptors +.86% of estrogen receptors negative tumors were pS2-. We observed correlation between pS2 and estrogen receptors values (r = 0.56; p < 0.0001) and between pS2 and progesterone receptors values (r = 0.53; p < 0.0001). Distributing the tumors in pS2+ and pS2-, we observed association between pS2+ and estrogen receptors + (chi 2 = 45.6; p < 0.0001) and pS2+ and progesterone receptors + (chi 2 = 43.1; p < 0.0001). However, we found a 18.5% of estrogen receptors + pS2- tumors. We observed a significant difference between GII and GIII tumoral grades (chi 2 = 5.51; p < 0.019), with a majority of pS2+ tumors in GII and pS2- tumors in GIII.

CONCLUSIONS

The estrogen receptors in estrogen receptors + ps2- tumors may be non functional. The presence of pS2 protein alternative to that of progesterone receptors may indicate a functional heterogeneity of the estrogen receptors system, which is of interest in evaluating prognosis and response to the hormonal therapy.