The oestrogen-progesterone receptor ratio: an indicator of breast cancer evolution

Two groups of patients were chosen from among 4,025 subjects examined in a breast screening program, one consisting of patients with stage I and the other of patients with stage IV breast cancer, characterized by neoplastic recurrence. In this comparison p53, HER and grading are of no direct help. We investigated receptor status at the time of the first operation and after complete surgical excision of the recurrence. The following variables were determined: oestrogen and progesterone receptor measures (ER, PR) in f.mol/ml, the 4 receptor phenotypes, the oestrogen-progesterone ratio and histological tumour grading in relation to oestrogen receptor positivity or negativity. Surgery consisted in quadrantectomy or total mastectomy, with axillary dissection or complete surgical excision of the recurrence. Adjuvant therapy was administered. The results show a different receptor percentage in recurrence compared to early breast cancer, which though not significant, indicates a reduced presence of ER+ PR+, ER- PR-, and an increase in the ER+PR- phenotype. Recurrence occurs more frequently when the lesion at the first operation is more advanced and if radiotherapy has not been included in the treatment. Histological grading shows a greater number of undifferentiated cells and a reduction in ER+ in recurrence, thus indicating a reduced target for the most widely used hormone treatments. The oestrogen-progesterone ratio is significantly increased (P < 0.01) in recurrence compared to stage I cancers. The cause of recurrence is a neoplastic embolism, often documented histologically. Recurrence does not necessarily mean a poor prognosis, because there is a survival rate after two years of 77% of the cases treated. These results obtained with widely used methods show the aggressiveness of some breast tumours, which can evolve and have a very poor prognosis even with the most complete therapy.