Breast-cancer-specific mortality in patients treated based on the 21-gene assay: a SEER population-based study

Abstract

The 21-gene Recurrence Score assay is validated to predict recurrence risk and chemotherapy benefit in hormone-receptor-positive (HR+) invasive breast cancer. To determine prospective breast-cancer-specific mortality (BCSM) outcomes by baseline Recurrence Score results and clinical covariates, the National Cancer Institute collaborated with Genomic Health and 14 population-based registries in the the Surveillance, Epidemiology, and End Results (SEER) Program to electronically supplement cancer surveillance data with Recurrence Score results. The prespecified primary analysis cohort was 40–84 years of age, and had node-negative, HR+, HER2-negative, nonmetastatic disease diagnosed between January 2004 and December 2011 in the entire SEER population, and Recurrence Score results (N=38,568). Unadjusted 5-year BCSM were 0.4% (n=21,023; 95% confidence interval (CI), 0.3–0.6%), 1.4% (n=14,494; 95% CI, 1.1–1.7%), and 4.4% (n=3,051; 95% CI, 3.4–5.6%) for Recurrence Score <18, 18–30, and ⩾31 groups, respectively (P<0.001). In multivariable analysis adjusted for age, tumor size, grade, and race, the Recurrence Score result predicted BCSM (P<0.001). Among patients with node-positive disease (micrometastases and up to three positive nodes; N=4,691), 5-year BCSM (unadjusted) was 1.0% (n=2,694; 95% CI, 0.5–2.0%), 2.3% (n=1,669; 95% CI, 1.3–4.1%), and 14.3% (n=328; 95% CI, 8.4–23.8%) for Recurrence Score <18, 18–30, ⩾31 groups, respectively (P<0.001). Five-year BCSM by Recurrence Score group are reported for important patient subgroups, including age, race, tumor size, grade, and socioeconomic status. This SEER study represents the largest report of prospective BCSM outcomes based on Recurrence Score results for patients with HR+, HER2-negative, node-negative, or node-positive breast cancer, including subgroups often under-represented in clinical trials.

Using the 21‐gene assay from core needle biopsies to choose neoadjuvant therapy for breast cancer: A multicenter trial

“…Retrospective studies have demonstrated that patients with low RS results are unlikely to respond well to chemotherapy but are more likely to respond to NHT, while higher RS predicts a greater likelihood of a good response to chemotherapy . These results also confirm prior studies showing that patients with a low RS have little to no benefit from chemotherapy, similar to the recently published reports of prospective outcomes in patients with RS less than 11 in the adjuvant setting for both node‐negative and node‐positive patients …”

First Prospective Multicenter Italian Study on the Impact of the 21-Gene Recurrence Score in Adjuvant Clinical Decisions for Patients with ER Positive/HER2 Negative Breast Cancer

“…Distribution of RS results, in both the N0 and N1 cohort, is consistent with most of the European decision impact studies and postmarketing data in large population datasets , with more than half of the patients presenting with low RS (<18), less than 10% presenting with high RS (>30), and the remainder being classified as intermediate RS (18–30). This distribution differs from original validation studies, in which populations were enriched with patients with higher RS , probably due to different patient selection criteria.…”

Breast carcinoma with an Oncotype Dx recurrence score <18: Rate of distant metastases in a large series with clinical follow‐up

“…Distant metastases developed in 0.4% of 1406 unselected consecutive patients in this group. Two other studies have reported outcome data in large patient populations treated based on the 21‐gene RS and found a similar incidence of distant recurrence and BC‐specific mortality in patients with a low RS . Only 1 of the 6 patients with distant metastasis in the current study had a tumor with an RS <11.…”