Fifteen-year prognostic discriminants for invasive breast carcinoma - National Surgical Adjuvant Breast and Bowel Project Protocol-06

BACKGROUND. This report updated previous findings, at the 15-year mark, of the National Surgical Breast and Bowel Project (NSAPB) Protocol B-06 with r espect to the treatment of invasive breast carcinoma and the effects of pat hologic features and the effects of some clinical features on its natural h istory. METHODS. Thirty-one pathologic and 6 clinical features that were observed i n a pathologic subset of 1039 evaluable patients were assessed as to their value in predicting survival, in predicting ipsilateral breast tumor recurr ence (IBTR), and in predicting the necessity for local breast irradiation a fter lumpectomy. The patients had been randomly assigned to treatment by lu mpectomy without local irradiation or to treatment by lumpectomy with local irradiation of the breast. A traditional and another statistical method we re used for this purpose. RESULTS. Multivariate analyses revealed that the presence of IBTR, race, hi stologic tumor type, nodal status, nuclear grade, and blood vessel invasion affected survival independently. Treatment, patient age, nuclear grade, pr esence of intraductal carcinoma, and a lymphocytic tumor infiltrate were fe atures that predicted IBTR by multivariate analyses. Irradiation reduced IB TR from 36% to 12% in the analyzed cohort. A test of interaction failed to reveal any pathologic or clinical feature that might have allowed for the o mission of local irradiation of the breast after lumpectomy. CONCLUSIONS, In addition to the influence of pathologic and clinical featur es on patient survival and IBTR, the site, histopathologic features, and ti me of occurrence of the latter allowed for insights into some important bio logic considerations concerning invasive breast carcinoma. Cancer 2001;91:1 679-87, (C) 2001 American Cancer Society.