Factors associated with prognosis in human breast cancer. III. Estradiol receptors and short term relapse.

Prognosis in breast cancer is one of the most important subjects currently studied because of the heterogeneity of the disease even inside the same clinical stage. Estrogen receptor determination in human breast cancer has been recognized as a prognostic factor since it is related to the long-term survival and disease-free interval. In a series of papers concerning prognosis in breast cancer this the third one which includes estrogen receptor determination in the multivariate analysis, because of the limitations of the clinical factor to conform stratification groups. We have analyzed the short term probability of relapse in a group of 136 patients treated for breast cancer. Multivariate stratification analysis was performed with the aid of Bintree computer program, which produces binary splits of the population according to the criterion of maximal reduction of variance and generates a binary stratification tree. Lymph node involvement is the most important prognostic factor in the probability of relapse. Patients without nodal involvement lacking estradiol receptor had 25% of relapse. It is therefore evident that estradiol receptor is a factor of prognostic value even inside node negative patients.