As reported in the Journal of Clinical Oncology, Pusztai et al developed the RSClinN+ tool—an integration of the 21-gene Oncotype DX Breast Recurrence Score (RS) test and clinicopathologic factors (tumor grade, tumor size, age)—that improved prognosis for invasive disease–free survival vs RS alone in hormone receptor–positive, HER2-negative, node-positive breast cancer.
Study Details
The study used patient-level data from 5,283 patients treated with chemoendocrine therapy (CET) vs endocrine therapy (ET) alone in the S1007 trial (N = 4,916) and S8814 trial (N = 367) trial to develop the tool. The primary outcome measure was 5-year invasive disease–free survival for pre- and postmenopausal woman. External validation of the tool was performed in 592 patients with node-positive disease in the Clalit Health Services registry, a large database containing comprehensive medical records of millions of patients within the Clalit Health Services system in Israel.
Key Findings
The RSClinN+ model was significantly more prognostic for 5-year invasive disease–free survival vs RS alone (P = .034 among premenopausal women; P <.001 among postmenopausal women) and vs the clinicopathologic model alone (P = .002 among premenopausal women; P < .001 among postmenopausal women).
Among postmenopausal women, RS showed an interaction with CET benefit vs ET (P = .016); the RSClinN+ absolute CET benefit ranged from < 0.1% to 21.5% over RS ranges 0–50. Among premenopausal patients with an RS ≤ 25, there was no significant interaction between RS and CET benefit. However, use of RSClinN+ showed, for example, that a 45-year-old premenopausal woman had an absolute CET benefit of 2.6% to 3.4% with low-grade, T1, N1 disease and an absolute benefit of 5.3% to 6.8% with high-grade, T2, N1 disease.
In the external validation cohort, RSClinN+ risk estimates were prognostic for 5-year invasive disease–free survival (hazard ratio = 1.75, 95% confidence interval [CI] = 1.38–2.20) and highly concordant with observed risk (Lin’s concordance = 0.92).
The investigators concluded: “RSClinN+ provides improved estimates of prognosis and absolute CET benefit for individual patients compared with RS or with clinical data alone and could be used in patient counseling.”
Lajos Pusztai, MD, DPhil, of Yale University School of Medicine, is the corresponding author of the Journal of Clinical Oncology article.
Disclosure: The study was supported by National Cancer Institute grants and others. For full disclosures of all study authors, visit the Journal of Clinical Oncology.
