Predicting recurrence in axillary-node negative breast cancer patients

Abstract

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 < or = 0.5 cm, 6% +/- 7 for tumors 0.6-1.0 cm, 16% +/- 9 for 1.1-2 cm, 29% +/- 12 for 2.1-5 cm, and 40% +/- 31 over 5 cm; (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 tumor < or = 1 cm, W/M (0% RR), (2) patients with ductal carcinoma in situ with microinvasion (0% RR), and (3) patients with tumors < or = 1 cm, 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 > 2 cm (RR 32% +/- 12), and (2) patients with tumors 1.1-2 cm, P/A (RR 21% +/- 14). These should receive adjuvant therapy. Groups with intermediate risk are patients with tumor 1.1-2 cm, 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.(ABSTRACT TRUNCATED AT 400 WORDS)