Pathologic findings from the National Surgical Adjuvant Breast and Bowel Projects (NSABP). Prognostic discriminants for 8-year survival for node-negative invasive breast cancer patients

Abstract

Twenty-two pathologic features (including estrogen and progesterone receptors) and four clinical features observed in 950 women with node-negative Stage I invasive breast cancer who enrolled in the National Surgical Adjuvant Breast and Bowel Projects (NSABP) protocol B-06 were evaluated for their possible prognostic significance. Preliminary univariate analysis revealed ten characteristics that were significant in this regard at the 1% level. Their assessment in a Cox regression model demonstrated only three to be prognostically important; notable among these were nuclear grade, histologic tumor type, and race. Life-table plots revealed that 86% of patients whose cancers exhibited good nuclear grade survived for 8 years as opposed to 64% in whom the nuclear grade was scored as poor. Analyses demonstrated three prognostic categories for histologic tumor type. Patients with either mucinous, tubular, or papillary cancers fared significantly better than those having not otherwise specific (NOS) or atypical medullary tumors. Survival for those with typical medullary, NOS combinations, or lobular invasive cancers was intermediate. Blacks fared worse than whites. Survival was correspondingly better or worse when two favorable or unfavorable characteristics were detected. The number of black women in this cohort was considered too small for further subset analysis although generally the pattern of findings suggested that survival was worse for blacks than for whites in all subsets. A review, as well as our own experience, suggested that nuclear grade is as good if not better as a predictor of survival in node negative patients as information derived from DNA analyses, immunohistochemical demonstration of erb-B2 overexpression, and, possibly, the tumor labeling index at predicting survival in node-negative patients.