The estrogen receptor test: a prognostic tool in primary breast cancer.

To evaluate the usefulness of the estrogen receptor test as a prognostic indicator, a retrospective study of 134 patients with primary breast cancer was carried out at the Ottawa Civic Hospital. The estrogen receptor values, measured in a single laboratory, were correlated with the recurrence rate and the survival time after recurrence. Other well-established prognostic data, such as stage of cancer, lymph-node involvement and menopausal state, have been similarly examined to ensure that information obtained from the estrogen receptor test offers more than a duplication of information from these traditional methods. It was found that this test is a useful prognostic tool when used on premenopausal women. The results of the study show that (a) breast cancer patients having positive estrogen receptor values have recurrences less frequently, (b) among estrogen receptor-negative patients there is more than a 50% chance of early recurrence in premenopausal women compared with less than a 20% chance in postmenopausal women, (c) conventional adjuvant chemotherapy in estrogen receptor-negative premenopausal patients does not prevent early recurrence, hence, this group requires more aggressive adjuvant treatment and (d) the method described by Heuson and colleagues for estrogen receptor determination follows the trends of better-established tests.