27 Background: Treatment planning for early-stage estrogen receptor (ER) positive, lymph node negative breast cancer was based on prognostic factors with limited predictive power such as age. The Recurrence Score (RS) from the Oncotype DX assay (ODX) provides predictive power transcending age but is rarely applied to the elderly or young patients (pts). We examined our experience with RS along the age continuum. Methods: Retrospective review was conducted of prospectively gathered breast cancer pts having a RS obtained as part of their cancer care. Eligibility for performance of the ODX was based on NCCN guidelines or physician discretion. Comparisons on RS were made by age groups (young: <45yrs; middle: >45yrs -<70yrs: elderly: >70yrs) using general linear regression model and the exact Wilcoxon Rank Sum Test. Results: 677pts had 681 tumors with RS available (89 young, 476 middle and 112 elderly pts). Median RS for the study pts was 17 (range 0-85) and 16, 17, and 15 for the young, middle, and elderly respectively. Median age was 58yrs (range: 27-95); young, middle, and elderly was 42, 58, and 74yrs respectively. Age as a continuous or categorical variable was not predictive of RS (p value = 0.38, 0.58 respectively). No significant differences were seen between age cohorts for histology, mitotic rate, lymphovascular invasion (LVI), grade, nodal status, stage, or strength of ER positivity. Mastectomy rates were higher in the young (57.5%), compared to the middle (42.5%) and elderly (39.6%) (p=0.02). Median invasive tumor size was 1.6, 1.5, and 1.5cm for young, middle, and elderly. Larger tumor size, as a continuous variable, equaled higher RS (p=0.046). Other significant factors predicting higher RS were increased mitosis (p<0.001), LVI (p=0.013), high grade (p<0.001), and weak (<10%) ER positivity (p<0.001). Nodal status, stage, and histology did not affect RS. Conclusions: Age has limited predictive power for treatment planning for breast cancer. Age alone should not preclude recommendations for performance of ODX in estrogen receptor positive lymph node negative early stage breast cancer as the RS distribution across the spectrum of age is well matched.
Treatment of Axillary Lymph Node-Negative, Estrogen Receptor-Negative Breast Cancer: Updated Findings From National Surgical Adjuvant Breast and Bowel Project Clinical Trials
