UBC Theses and Dissertations
Steroid hormone receptors and plasminogen activator in human breast cancer : their value in prognosis Humphries, Karin Hartmann
Steroid hormone receptor analysis has emerged as an important aid to prognosis in human breast cancer. The availability of ¹²⁵I-labeled estradiol led to the development of a dual-label assay for the simultaneous determination of estrogen and progesterone receptor content. There are indications that plasminogen activator activity may also serve as a prognostic indicator in breast cancer. Two methods, one fluorometric and the other spectrophotometric were examined for their suitability in assaying for plasminogen activator activity. Both assays were found to be equally suitable for the determination of this enzyme in breast tumour cytosols. Cytosol from tumour samples stored at -70°C for 18 - 52 months was assayed for steroid receptor content and plasminogen . activator activity. Estrogen receptor (ER) values determined at the time of the original assay were compared with the re-assayed estrogen receptor content. The results showed that this steroid receptor is remarkably stable to storage at -70°C. Comparisons between the two steroid receptors and plasminogen activator (PA) activity showed significant correlations between estrogen receptor and progesterone receptor (PgR) content and between progesterone receptor and plasminogen activator activity.There was no significant correlation between ER and PA activity. Survival curves were constructed to examine the effect of steroid receptor content and plasminogen activator activity on the survival of breast carcinoma patients. Due to the limited number of patients available, statistically significant differences in survival were not evident. However, there was an indication that estrogen receptor positive patients survived longer than their estrogen receptor negative counterparts. PA activity and progesterone receptor content did not appear to influence survival.