A prognostic score in histological node negative breast cancer

Between October 1977 and December 1983, 379 consecutive patients have been treated for unilateral, non-metastatic breast cancer, either with conservative (n = 205) or radical surgery (n = 174), with axillary dissection in all the cases. None of them had histologically proved lymph node involvement. Oestrogen receptor (ER) and progesterone receptor (PR) levels were measured on each tumour. Levels greater than 5 fmol mg-1 cytosolic protein were considered as positive for both ER and PR. At 5 years, overall survival (OS) and disease-free survival (DFS) are respectively 88% and 78%. Unifactorial analysis using Kaplan and Meier estimates and the log rank test revealed that OS was significantly related to age (P less than 0.05), tumour size (P less than 0.001), histological grading (SBR) (P less than 0.01), ER (P less than 0.001) and PR (P less than 0.001). DFS was significantly related to the same factors. Menopausal status, number of breast tumour foci and previous familial history of breast cancer were not significant. Multifactorial analysis revealed that DFS was significantly related to age (bad prognosis (b.p.) less than or equal to 37 years old), tumour size and histological grading (b.p. SBR = 3), and that OS was significantly related to tumour size and PR (b.p. PR less than or equal to 5 fmol mg-1 protein). A prognostic score has been constructed for both DFS and OS. These scores divide our patients into three significantly different (P less than 0.0001) groups with good, intermediate and bad prognosis.