Prognostic impact of surgery for early-stage invasive breast cancer on breast cancer-specific survival, overall survival, and recurrence risk: a population-based analysis

Effect of 21-gene recurrence score in decision-making for surgery in early stage breast cancer

Aim

We aimed to assess the role of 21-gene recurrence score (RS) in the decision-making for surgical treatment in early stage breast cancer and compared the outcomes between breast-conserving surgery (BCS) and mastectomy (MAST) among various 21-gene RS groups.

Methods

We included patients with stage T1-2M0M0 and estrogen receptor-positive breast invasive ductal carcinoma who underwent BCS + radiotherapy or MAST between 2004 and 2012 as part of the Surveillance, Epidemiology, and End Results program. Data were analyzed using binomial logistic regression, multivariate Cox proportional hazards models, and propensity score matching (PSM).

Results

We enrolled 34,447 patients including 22,681 (65.8%) and 11,766 (34.2%) who underwent BCS and MAST, respectively. Patients with high-risk RS were more likely to receive MAST. Multivariate analysis indicated that patients with intermediate-risk (P<0.001) and high-risk (P<0.001) RS had poor breast cancer-specific survival (BCSS), as compared to those with low-risk RS. Moreover, patients who underwent MAST also exhibited poor BCSS (P<0.001), as compared to those who underwent BCS. In low-risk (P<0.001) and intermediate-risk (P=0.020) RS groups, patients who underwent MAST had poor BCSS, as compared to those treated with BCS. However, BCSS was comparable between patients who underwent MAST and BCS (P=0.952); similar trends were also observed after PSM.

Conclusion

The 21-gene RS may impact the decision-making for surgery in early stage breast cancer. Our study provides additional support for a shared decision-making process for BCS when both local management options are appropriate choices regardless of the 21-gene RS.

The 21-gene recurrence score and effects of adjuvant radiotherapy after breast conserving surgery in early-stage breast cancer

Aim: To investigate the associations with the 21-gene recurrence score (RS) and effect of adjuvant radiotherapy (RT) for early-stage breast cancer after breast conserving surgery. Methods: We included 13,246 patients in the SEER database. Results: Patients with a higher RS were independently related to nonreceipt of RT (p < 0.001). In both the traditional and Trial Assigning Individualized Options for Treatment (TAILORx) RS cut-offs, the receipt of RT was not related to better breast cancer-specific survival in low- and high-risk RS groups, but was independently related to better breast cancer-specific survival in intermediate-risk RS group before (p = 0.029) and after (p = 0.001) propensity score matching. Conclusion: The 21-gene-RS may impact the decision-making of adjuvant RT in early-stage breast cancer after breast conserving surgery. The survival benefit of adjuvant RT may be limited to patients with intermediate-risk RS.

Noninferior Outcome After Breast-Conserving Treatment Compared to Mastectomy in Breast Cancer Patients With Four or More Positive Lymph Nodes

Introduction: We conducted a non-inferiority analysis using real-world data to compare the survival outcomes of stage T1-2N2-3 (tumor size ≤5 cm and four or more node metastases) breast cancer after breast-conserving surgery (BCS) and mastectomy (MAST). Methods: The study included patients with stage T1-2N2-3 invasive breast carcinoma from the Surveillance, Epidemiology, and End Results program, who underwent BCS or MAST between 2004 and 2012, along with both radiotherapy and chemotherapy. The statistical analyses used included the chi-squared test, multivariate Cox proportional hazards models, and propensity score matching (PSM). Results: The study population comprised 13,263 patients, including 4,787 (36.1%) and 8,476 (63.9%) patients who were treated with BCS and MAST, respectively. Patients with younger age and advanced stage were more likely to have received MAST. The probability of receiving MAST increased over the years, while the probability of BCS decreased (p < 0.001). The 5-year breast cancer-specific survival (BCSS) was 86.1% in the BCS cohort compared to 83.1% in the MAST cohort (p < 0.001). Surgical procedure was an independent prognostic factor for BCSS. Patients who received MAST had worse BCSS than those treated with BCS (hazard ratio = 1.179, 95% confidence interval = 1.087-1.278, p < 0.001). These results remained significant after stratification by age, tumor grade, T stage, N stage as well as marital status. Similar results were obtained after PSM. Conclusions: BCS resulted in noninferior outcome than MAST in patients with T1-2/N2-3 invasive breast carcinoma. BCS may therefore be an optimal treatment option when both treatment options are feasible and appropriate.