Journal of Clinical Oncology, Vol 10, 438-446, Copyright © 1992 by American Society of Clinical Oncology
Aromatase activity and estradiol in human breast cancer: its relationship to estradiol and epidermal growth factor receptors and to tumor-node-metastasis staging
P Bolufer, E Ricart, A Lluch, C Vazquez, A Rodriguez, A Ruiz, F Llopis, J Garcia- Conde and R Romero
Department of Clinical Pathology, Hospital La Fe, Valencia, Spain.
PURPOSE: The present report attempts to clarify whether there is a
relationship between aromatase activity (ARAC) and estradiol (E2), hormonal
receptors, E2 receptor (ER), and epidermal growth factor receptor (EGFR),
as well as with tumor stage and histopathology in human breast cancers.
MATERIALS AND METHODS: We studied 225 breast carcinomas, 67 of which were
premenopausal and 158 postmenopausal. In each sample, ARAC, EGFR, ER, and
E2 were quantified. ARAC was quantified by Thompson and Siiterii's method,
EGFR was quantified with a two-point assay method using radioactive iodine
(125I)-EGF as ligand, and ER was measured by the Scatchard method using
3H-E2. E2 was quantified by radioimmunoassay in the diethylether tumor
extract. RESULTS: ARAC was found in 64% of the cancers studied. There is a
strong direct association between ARAC and tumor size in postmenopausal
patients (P = .001). In the postmenopausal group, the proportion of
ARAC-positive (ARAC+) tumors is significantly higher among ER-positive
(ER+) than ER-negative (ER-) ones (P less than .001). ER+ tumors also have
significantly higher levels of E2 than do ER- ones (P less than .0001);
similarly, ARAC+ tumors have significantly higher levels of E2 than do
ARAC- ones (P less than .0001). There is a significant multiple linear
correlation between the log of the levels of ARAC, ER, and EGFR and the log
of tumor E2 (P less than .0001). The correlation coefficients obtained show
that ARAC and ER have a positive effect on tumor E2. CONCLUSION: The
results obtained suggest the importance of tumor ARAC in the tumoral levels
of E2 and reinforce the possible biologic significance of tumor ARAC,
especially in postmenopausal breast carcinoma patients.
