Validation of the RSClin risk calculator in the National Cancer Database

Guidelines recommend the use of genomic assays such as OncotypeDx to aid in decisions regarding the use of chemotherapy for hormone receptor-positive, HER2-negative breast cancer. The RSClin prognostic tool integrates OncotypeDx and clinicopathologic features to predict distant recurrence and chemotherapy benefit, but further validation is needed before clinical adoptation. A study including 285.441 patients from the National Cancer Database found that chemotherapy was associated with improved overall survival only in the groups of patients with RSClin-predicted intermediate (aHR 0.68; 95% CI 0.60-0.79) and high (0.66; 0.61-0.72) benefit. Consistent benefit was seen in the subset wth low OncotypeDx score (<26) and intermediate (aHR 0.66; 95% CI 0.53-0.82) of high (0.71; 0.58-0.86) RSClin-predicted benefit, while no survival benefit with chemotherapy was seen in patients with a high OncotypeDx score and low RSClin-predicted benefit (1/70; 0.41-6.99). The authors conclude that RSClin may identify high-risk patients who benefit from treatment intensification more accurately than OncotypeDx.