Clinicopathological characteristics, adjuvant chemotherapy decision and disease outcome in patients with breast cancer with a 21-gene recurrence score of 26-30

Clinical outcomes in estrogen receptor-positive early-stage breast cancer patients with Recurrence Score 26-30: observational real-world cohort study

Data on adjuvant chemotherapy (CT) benefit in ER + HER2‒ early-stage breast cancer (EBC) patients with Recurrence Score (RS) 26-30 are limited. This real-world study evaluated the relationships between the RS, adjuvant treatments, and outcomes in 534 RS 26-30 patients tested through Clalit Health Services (N0: n = 394, 49% CT-treated; N1mi/N1: n = 140, 62% CT-treated). The CT-treated and untreated groups were imbalanced (more high-risk clinicopathologic characteristics in CT-treated patients). With median follow-up of 8 years, Kaplan-Meier estimates for overall survival (OS), distant recurrence-free survival (DRFS), and BC-specific mortality (BCSM) were not significantly different between CT-treated and untreated N0 patients. Seven-year rates (95% CI) in CT-treated vs untreated: OS, 97.9% (94.4-99.2%) vs 97.9% (94.6-99.2%); DRFS, 91.5% (86.6-94.7%) vs 91.2% (86.0-94.6%); BCSM, 0.5% (0.1-3.7%) vs 1.6% (0.5-4.7%). For N1mi/N1 patients, OS/DRFS did not differ significantly between treatment groups; whereas BCSM did (1.3% [0.2-8.6%] vs 6.2% [2.0-17.7%] for CT-treated and untreated patients, respectively, p = 0.024).

Association of 21-gene recurrence score and locoregional recurrence in early breast cancer patients

BACKGROUND: The 21-gene recurrence score (RS) assay has been validated to predict the risk of disease-free survival in estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer patients. However, its relation with locoregional recurrence (LRR) risk is unclear. OBJECTIVE: This study aimed to explore the ability of RS to predict LRR risk. METHODS: Consecutive ER-positive, HER2-negative, pT1, pN0-1, and M0 early breast cancer patients were analyzed retrospectively. According to RS, patients were divided into low- (RS < 18), intermediate- (RS 18–30), and high-risk (RS ⩾ 31) groups. The primary endpoint was LRR. Subgroup analysis was conducted according to different nodal statuses and surgery types. RESULTS: A total of 1558 patients were enrolled: 354 (22.7%), 788 (50.6%), and 416 (26.7%) patients in the low-, intermediate-, and high-risk groups, respectively. The median follow-up time was 53 months, and 2, 8, and 14 LRR events were observed in the low-, intermediate-, and high-risk groups, respectively (P= 0.004). Both univariate (P= 0.009) and multivariate (P= 0.010) analyses demonstrated that 21-gene RS was correlated with LRR. Compared to low-risk patients, high-risk patients were at greater risk of LRR (HR 5.75, 95% CI 1.30–25.31, P= 0.021). Among pN0 (P= 0.033), pN1 (P= 0.049) and postmastectomy patients (P= 0.012), 21-gene RS remained predictive of the risk of LRR. CONCLUSION: The 21-gene RS assay was significantly associated with the risk of LRR in ER-positive, HER2-negative early breast cancer patients. Among patients with different nodal statuses and patients receiving mastectomy, RS remained predictive of the risk of LRR.

Secondary Invasive Breast Events among Patients with Hormone-Positive Breast Cancer and High-Risk Oncotype DX Recurrence Scores 26-30 and ≥31

BACKGROUND

The Oncotype DX Recurrence Score (ODx RS) is the most widely adopted genomic assay used to guide treatment for patients with early-stage, hormone-positive (HR+) breast cancer (BC), with higher scores predicting greater risk of recurrence and benefit from chemotherapy. Patients with ODx RS >25 typically recieve adjuvant chemotherapy; however, data regarding efficacy of chemotherapy for reducing recurrence in this population have been mixed.

OBJECTIVES

This study aimed to evaluate outcomes of patients with early-stage HR+ BC with high-risk ODx RS (26-30 and ≥31) in order to assess treatment patterns and outcomes. We hypothesized that the benefit of chemotherapy in these groups may be minimal and that select patients may forgo chemotherapy in favor of more aggressive endocrine therapy and ovarian suppression.

METHODS

We performed a retrospective analysis of 515 patients with early-stage, HR+ BC with high-risk ODx RS 26-30 and ≥31 treated between 2006 and 2018. Patients were stratified by RS: low-risk (≤10), intermediate-risk (11-25), and high-risk (≥26). The Kaplan-Meier method was used to estimate the time to secondary invasive breast events (SIBE) or distributions overall and among different RS groups with the log rank test used to compare distributions between groups.

RESULTS

Rates of chemotherapy administration were 7% among the low-risk group, 18% among the intermediate-risk group, and 83% among high-risk patients with 41 SIBE (8%) reported. When stratified by ODx RS, 5-year rates of SIBE were 4%, 6%, and 16% for low-risk, intermediate-risk, and high-risk RS, respectively. Among the 27 lymph node (LN)-negative patients with ODx RS 26-30, 74% received chemotherapy. The 5-year rate of SIBE was 25% among patients who received chemotherapy and 33% among those who did not (p = 0.5489). Among the 23 LN-negative patients with ODx RS ≥31, 91% of patients received chemotherapy. The 5-year rate of SIBE was 0% both with and without chemotherapy.

CONCLUSIONS

There was no statistically significant difference in SIBE for patients with high-risk ODx RS based on chemotherapy treatment. More aggressive endocrine therapy with ovarian suppression has become an alternative to chemotherapy among patients with intermediate-risk ODx RS (16-25). This approach may be useful among patients with high-risk ODx RS, with additional studies needed in this patient population.

Adjuvant chemotherapy and survival outcome in node-negative breast cancer with a 21-gene recurrence score of 26-30

Aim: To investigate the benefit of chemotherapy among early-stage breast cancer patients with 21-gene recurrence scores of 26-30. Methods: We identified 3754 patients in the Surveillance, Epidemiology, and End Results database. Results: 57.6% of the patients received adjuvant chemotherapy. Patients with higher tumor grade, larger tumors and younger age were more likely to receive chemotherapy. The receipt of chemotherapy was independently associated with better breast cancer-specific survival than in patients without chemotherapy before (p = 0.016) and after (p = 0.043) propensity score matching. The sensitivity analyses showed that survival gain was pronounced in patients with poorly differentiated or undifferentiated disease. Conclusions: Adjuvant chemotherapy improves the outcome for early-stage breast cancer with 21-gene recurrence score of 26-30, especially for patients with high-grade tumors.