Correlations between clonogenicity and prognostic factors in human breast cancer.

The pursuit of more effective systemic treatments in breast cancer has been limited by a failure to maintain or grow tumour cells in vitro. This study reports our experience in obtaining clonogenic growth in 54 primary breast cancers obtained at mastectomy. Of 47 assays free of infection, clonogenic growth was achieved in 22 (41 per cent). Only 5 of 23 oestrogen receptor positive tumours grew compared to 14 of 21 oestrogen receptor negative tumours chi 2 = 9.03; P less than 0.01). None of the 5 cytosolic receptor positive tumours contained a nuclear receptor for oestrogen. Growth was not related to tumour stage, menopausal status, age or histological grade. Receptor negative tumours had higher thymidine labelling indices, but these were no different to the tumours grown in the assay.