National trends in neoadjuvant chemotherapy utilization in patients with early-stage node-negative triple-negative breast cancer: the impact of the CREATE-X trial

The Prevalence of Sentinel Lymph Node Positivity and Implications for the Utility of Frozen Section Diagnosis Following Neoadjuvant Systemic Therapy in Patients with Clinically Node-Negative HER2-Positive or Triple-Negative Breast Cancer

BACKGROUND

Axillary dissection is the standard of care for patients with positive sentinel lymph nodes (SLNs) following neoadjuvant systemic therapy. Frozen section can provide intraoperative information regarding the need for axillary dissection during the index operation. However, there are limited data on the utility of frozen section in patients with clinically node-negative (cN0) HER2-positive or triple-negative breast cancer.

METHODS

We conducted a single-institution observational cohort study including patients with non-inflammatory, cN0, HER2-positive or triple-negative breast cancer treated with neoadjuvant systemic therapy between 2015 and 2019. We estimated the prevalence of SLN positivity and the diagnostic test characteristics of SLN frozen section.

RESULTS

Overall, 662 patients were eligible for inclusion, and 44 patients had one or more positive SLNs (prevalence: 6.6%, 95% confidence interval [CI] 4.9-8.8). There were 490 (74.0%) patients who had intraoperative frozen section, and 19 (3.9%) tested positive among 33 (6.7%) with positive final pathology. Frozen section sensitivity was 57.6% (95% CI 39.2-74.5), specificity was 100% (95% CI 99.2-100), positive predictive value was 100% (95% CI 82.4-100), and negative predictive value was 97.0% (95% CI 95.1-98.4). The sensitivity of frozen section for detection of micrometastases or isolated tumor cells was 35.3% (95% CI 14.2-61.7).

CONCLUSION

In patients with cN0 HER2-positive or triple-negative breast cancer who have been treated with neoadjuvant therapy, positive SLNs are uncommon and frozen section sensitivity is modest. Decisions to defer SLN evaluation to final pathology, which may be reasonable in many settings, can be informed, in part, by these findings.

Neoadjuvant chemotherapy for breast cancer in Italy: A Senonetwork analysis of 37,215 patients treated from 2017 to 2022

BACKGROUND

Adoption of neoadjuvant chemotherapy (NACT) in the "real world" has been poorly investigated. Aim of this study was to examine the rate of NACT in Italy, trends over time and determinants of therapeutic choices.

METHODS

Senonetwork, the recognized network of Breast Centers in Italy, has developed a voluntary national data warehouse with the aim to monitor and improve treatments quality. A retrospective analysis was conducted among 58,661 breast cancer (BC) patients treated between 2017 and 2022 by 24 high-volume Breast Centers participating in the project.

RESULTS

After subset exclusion, 37,215 primary BC patients were analysed, 32,933 underwent primary-breast-surgery and 4,282 underwent NACT. From 2017 to 2022, the overall NACT incidence increased particularly for HR-/HER2+, Triple-Negative, and HR+/HER2+ BC (p < 0.001). In cN + patients the recommendation to axillary lymph-node dissection after NACT decreased over time along with an increase of <4 lymph-nodes removed (p < 0.001). Immediate breast reconstruction and indication for nipple sparing mastectomy increased significantly over time (OR = 1.10, p = 0.011 and OR 1.14, p < 0.001, respectively). On multivariate analysis, there was a trend towards an increased adoption of conservative treatment for HR-/HER2+ (p = 0.01) and Triple Negative tumors (p = 0.06). Implementation of NACT varied significantly among Breast-Centers from 3.8 to 17.7 % (p < 0.001).

CONCLUSION

The impact of NACT on the subsequent surgical management is substantial and continues to evolve over time, resulting in less-extensive surgery. Even among high-volume Centers NACT implementation rate is still highly variable. Although we registered a significant increase in its use during the study period, these results need to be further improved.

Does Neoadjuvant Chemotherapy in Clinical T1-T2 N0 Triple-Negative Breast Cancer Increase the Extent of Axillary Surgery?

BACKGROUND

Current management strategies for early-stage triple-negative breast cancer (TNBC) include upfront surgery to determine pathologic stage to guide chemotherapy recommendations, or neoadjuvant chemotherapy (NAC) to de-escalate surgery, elucidate tumor response, and determine the role of adjuvant chemotherapy. However, patients who receive NAC with residual pathological nodal (pN) involvement require axillary lymph node dissection (ALND) as they are Z11/AMAROS ineligible. We aimed to evaluate the impact of NAC compared with upfront surgery on pN status and ALND rates in cT1-2N0 TNBC.

METHODS

The National Cancer Database (NCDB) was queried for women with operable cT1-2N0 TNBC from 2014 to 2019. Demographic, clinicopathologic, and treatment data were collected. Multivariable linear regression analysis was performed to assess the odds of pN+ disease and undergoing ALND.

RESULTS

Overall, 55,624 women were included: 26.9% (n = 14,942) underwent NAC and 73.1% (n = 40,682) underwent upfront surgery. The NAC cohort was younger (mean age 52.9 vs. 61.3 years; p < 0.001) with more cT2 tumors (71.6% vs. 31.0%; p < 0.001), and had lower ALND rates (4.3% vs. 5.5%; p < 0.001). The upfront surgery cohort was more likely to have one to three pathologically positive nodes (12.1% vs. 6.5%; odds ratio [OR] 2.37, 95% confidence interval (CI) 2.17-2.58; p < 0.001) but there was no difference in the likelihood of ALND (OR 1.1, 95% CI 0.99-1.24; p = 0.08).

CONCLUSION

Patients who underwent upfront surgery were more likely to be pN+; however, ALND rates were similar between the two cohorts. Thus, the use of NAC does not result in a higher odds of ALND and the decision for NAC should be individualized and based on modern guidelines and systemic therapy benefits.