PROGNOSTIC VALUE OF STEROID-RECEPTORS AFTER LONG-TERM FOLLOW-UP OF 2257 OPERABLE BREAST CANCERS

The prognostic value of oestrogen receptor (ER) and progesterone recep tor (PR) was estimated through a multicentric study of 2257 operable b reast cancer patients followed up for a median of 8.5 years. None of t he patients had received adjuvant therapy. The series included 33.3% s tage I patients, 57.1% stage II, 5.7% stage IIIa and 2.4% stage IIIb. At the end point of the study 589 metastases and 537 deaths from cance r were recorded. Receptor measurements were performed by radioligand a ssay according to a uniform protocol. A total of 68.8% of the rumours were ER positive and 54.0% PR positive (greater than or equal to 10 fm ol mg(-1) cytosol protein). In univariate analysis, ER and PR status ( positive/negative) were of prognostic value (P<0.001) for the disease free interval (DFI), the metastases-free interval (MFI) and the overal l survival (OS). The OS of the patients after a first metastasis was a lso significantly different between ER-positive and -negative tumours (P<0.001). In multivariate analysis (Cox proportional hazard model, 16 65 patients), only the ER status showed a significant difference (P<0. 01) between positive and negative groups regarding the DFI, MFI and OS . By using Cox nonproportional, time-dependent models, we show that th e predictive value of ER status of the primary tumour decreases by app roximately 20% per year, losing its significance after 8 years of foll ow-up. Overall, when compared with TNM and histological grading, ER an d PR status have a low prognostic value, their major interest remainin g solely in the domain of therapeutic decision.