Multicenter retrospective study on the use of Curebest™ 95GC Breast for estrogen receptor-positive and node-negative early breast cancer

Background The benefits of postoperative chemotherapy in patients with estrogen receptor (ER)-positive breast cancer remain unclear. The use of tumor grade, Ki-67, or ER expression failed to provide an accurate prognosis of the risk of relapse after surgery in patients. This study aimed to evaluate whether a multigene assay Curebest™ 95GC Breast (95GC) can identify the risk of recurrence and provide more insights into the requirements for chemotherapy in patients. Methods This single-arm retrospective multicenter joint study included patients with ER-positive, node-negative breast cancer who were treated at five facilities in Japan and had received endocrine therapy alone as adjuvant therapy. The primary lesion specimens obtained during surgery were analyzed using the 95GC breast cancer multigene assay. Based on the 95GC results, patients were classified into low-risk (95GC-L) and high-risk (95GC-H) groups. Results The 10-year relapse-free survival rates were 88.4 and 59.6% for the 95GC-L and 95GC-H groups, respectively. Histologic grade, Ki-67, and PAM50 exhibited a significant relationship with the 95GC results. The segregation into 95GC-L and 95GC-H groups within established clinical factors can identify subgroups of patients using histologic grade or PAM50 classification with good prognosis without receiving chemotherapy. Conclusions Based on the results of our retrospective study, 95GC could be used to evaluate the long-term prognosis of ER-positive, node-negative breast cancer. Even though further prospective validation is necessary, the inclusion of 95GC in clinical practice could help to select optimal treatments for breast cancer patients and identify those who do not benefit from the addition of chemotherapy, thus avoiding unnecessary treatment.

Predicting the response of neoadjuvant chemotherapy in hormone receptor- positive and HER2-negative breast cancer with axillary lymph node metastasis by a multigene assay (GenesWell™ BCT)

The GenesWell™ BCT (BCT score) is a recently developed multigene assay that predicts the risk of distant recurrence in patients with hormone receptor-positive (HR+) and HER2 negative (HER2-) early breast cancer (BC). The ability of the assay to predict the response to neoadjuvant chemotherapy (NACT) has not been established to date. Biopsy specimens of HR+/HER2- BC patients with axillary lymph node (LN) metastasis who underwent NACT were analyzed using the BCT score. The modified breast cancer test (BCT) score was developed and classified into high-and low-response groups. A total of 88 patients were available for the BCT score among 108 eligible patients. The median follow-up duration was 35.9 (7.8-128.5) months. Among these, 61 (65.1%) had cN1 and 53 (60.2%) had cT1 or T2. The BCT score was low in 25 (28.4%) patients and high in 63 (71.6%) patients. Among 50 patients with pathologic complete response or partial response, 41 (82.0%) were in the high-response group, and 9 (18.0%) were in the low-response group. Among 38 patients with stable disease or progressive disease, 22 (57.9%) patients were in the high-response group, and 16 (42.1%) were in the low-response group (p = 0.025). Ki-67 before NACT was a significant factor for predicting tumor response (p = 0.006; 3.81 [1.50-10.16]). The BCT score showed a significant response to NACT (p = 0.016; 4.18 [1.34–14.28]). A significant difference was found in distant metastasis-free survival between the high and low response groups (p = 0.004). We demonstrated that the BCT score predicts NACT responsiveness of HR+/HER2- BC with LN metastasis and might help determine whether to undergo NACT or not. Further studies are warranted to validate these findings.

Changes in Recurrence Score by neoadjuvant endocrine therapy of breast cancer and their prognostic implication

BackgroundNeoadjuvant endocrine therapy (NET) can improve surgical outcomes in postmenopausal patients with hormone receptor-positive breast cancer. The Ki67 labelling index after NET has a better prognostic power than that at baseline. However, it remains unknown whether a multigene assay with post-treatment samples could predict the prognosis better than that with pretreatment samples.MethodsThe prognostic value of the multigene assay Oncotype DX Recurrence Score (RS) was investigated using pretreatment and post-treatment samples from a multicentre NET trial, JFMC34-0601 (UMIN C000000345), where exemestane was given at 25 mg/day for 24 weeks.ResultsBoth pretreatment and post-treatment RSs were significantly associated with disease-free survival (DFS) (p=0.005 and 0.002, respectively). The combination of pretreatment and post-treatment RSs was also a predictor of DFS (p=0.002) and superior to preoperative endocrine prognostic index (PEPI). Furthermore, combined RS was the only independent prognostic factor in the multivariate analysis among the three RSs (p=0.04). In addition, combined RS could differentiate early recurrence in the high-risk group from mid/late recurrence in the intermediate-risk group, suggesting possible differential treatment strategies based on the risk categories indicated by the combined RS.ConclusionsThe combination of pretreatment and post-treatment RSs could provide pivotal information for predicting DFS and differentiating early recurrence in the high-risk group from mid/late recurrence in the intermediate-risk group in patients with hormone receptor-positive breast cancer. A larger study is required to validate the results.