Predicting recurrence in axillary-node negative breast cancer patients

Summary This study attempted to identify the risk groups in axillary node negative breast cancer patients using validated first-generation prognostic clinical and pathologic factors. An updated 10-year follow-up in 407 such patients treated by surgery alone at Roswell Park between 1976–1987 showed a 10-year recurrence rate (RR) of 19% (95% confidence interval ±5%). Predictors of outcome were, in order of strength: (1) Tumor size (p= 0.0006); RR at 10 years was 2% ± 4 for tumors 0.5cm, 6% ± 7 for tumors 0.6-1.0cm, 16% ± 9 for 1.1–2cm, 29% ± 12 for 2.1–5cm, and 40% ± 31 over 5cm; (2) Histologic differentiation (p = 0.017); poorly differentiated/anaplastic (P/A) tumors had a greater RR (24% ± 8) than well or moderately differentiated (W/M) tumors (13% ± 8); (3) Age (p = 0.046); patients < 35 showed a RR of 28% ± 20, pts 35–50, 22% ± 10, and pts > 50, 17% ± 7 (p = 0.046). Cox Model analysis showed tumor size (4 groups) significant at < 0.0001, histologic differentiation (2 groups) significant at < 0.0005 after allowing for size, and age (±50) significant at <0.05 after allowing for size and differentiation.Combining these variables into subgroups enables selecting groups at various risks of recurrence. Groups with low risk are: (1) patients with tumor1cm, W/M (0% RR), (2) patients with ductal carcinomain situ with microinvasion (0% RR), and (3) patients with tumors 1cm, P/A (8% RR). In a suggestive finding in this last group, those over age 50 achieved a RR of 3% ± 6, while those age 50 or less had RR 14% ± 15. With the exception of this last group, all should be considered highly curable using loco-regional therapy alone, and might be spared the risks and costs of routine systemic adjuvant therapy. Groups with high risk are: (1) patients with tumors > 2cm (RR 32% ± 12), and (2) patients with tumors 1.1–2cm, P/A (RR 21% ± 14). These should receive adjuvant therapy. Groups with intermediate risk are patients with tumor 1.1-2cm, W/M (RR 12% ± 12). In a suggestive finding, those in this group over age 50 had a RR of 11% ± 12, while those up to 50 had a RR of 17% ± 30. These patients should be considered to be prime candidates for clinical trials.Adding second generation factors such as DNA ploidy or S-phase fraction to first generation factors should provide additional information on which to base therapy decisions, particularly in the gray area of intermediate risk. Our study indicates that node-negative breast cancer patients represent a heterogeneous population in terms of risk and prognosis, and that an individualized approach to adjuvant therapy should be taken.Presented in part at the 14th annual San Antonio Breast Cancer Symposium, December 6-7, 1991, and the American Association for Cancer Research, San Diego, CA, May 20-23, 1992