Long-term prognosis in breast cancer is associated with residual disease after neoadjuvant systemic therapy but not with initial nodal status

Prognostic effect of nodal status before and after neoadjuvant chemotherapy in breast cancer: a Dutch population-based study

PURPOSE

In breast cancer, neoadjuvant chemotherapy (NAC) can downstage the nodal status, and can even result in a pathological complete response, which is associated with improved prognosis. This study aimed to determine the prognostic effect of nodal status before and after NAC.

METHODS

Women with breast cancer treated with NAC were selected from the Netherlands Cancer Registry if diagnosed between 2005 and 2019, and classified based on nodal status before NAC: node-negative (cN0), or node-positive based on fine needle aspiration cytology or core needle biopsy (cN+). Subgroups were based on nodal status after NAC: absence (ypN0) or presence (ypN+) of nodal disease. Five-year overall survival (OS) was assessed with Kaplan-Meier survival analyses, also per breast cancer molecular subtype. To adjust for potential confounders, multivariable analyses were performed.

RESULTS

A total of 6,580 patients were included in the cN0 group, and 11,878 in the cN+ group. The 5-year OS of the cN0ypN0-subgroup was statistically significant better than that of the cN+ypN0-subgroup (94.4% versus 90.1%, p < 0.0001). In cN0 as well as cN+ disease, ypN+ had a statistically significant worse 5-year OS compared to ypN0. For hormone receptor (HR)+ human epidermal growth factor receptor 2 (HER2)-, HR+ HER2+, HR-HER2+, and triple negative disease, respectively, 5-year OS in the cN0ypN+-subgroup was 89.7%, 90.4%, 73.7%, and 53.6%, and in the cN+ypN+-subgroup 84.7%, 83.2%, 61.4%, and 48.8%. In multivariable analyses, cN+ and ypN+ disease were both associated with worse OS.

CONCLUSION

This study suggests that both cN-status and ypN-status, and molecular subtype should be considered to further improve prognostication.

A Survey of Practice Patterns for Clinical Nodal Staging Prior to Neoadjuvant Chemotherapy in Breast Cancer

BACKGROUND

The importance of clinical staging in breast cancer has increased owing to the wide use of neoadjuvant systemic therapy (NST). This study aimed to investigate the current practice patterns regarding clinical nodal staging in breast cancer in real-world settings.

MATERIALS AND METHODS

A web-based survey was administered to board-certified oncologists in Korea, including breast surgical, medical, and radiation oncologists, from January to April 2022. The survey included 19 general questions and 4 case-based questions.

RESULTS

In total, 122 oncologists (45 radiation, 44 surgical, and 33 medical oncologists) completed the survey. Among them, 108 (88%) responded that clinical staging before NST was primarily performed by breast surgeons. All the respondents referred to imaging studies during nodal staging. Overall, 64 (52.5%) responders determined the stage strictly based on the radiology reports, whereas 58 (47.5%) made their own decision while noting radiology reports. Of those who made their own decisions, 88% referred to the number or size of the suspicious node. Of the 75 respondents involved in prescribing regimens for neoadjuvant chemotherapy, 58 (77.3%) responded that the reimbursement regulations in the selection of NST regimens affected nodal staging in clinical practice. In the case-based questions, high variability was observed among the clinicians in the same cases.

CONCLUSIONS

Diverse assessments by specialists owing to the lack of a clear, harmonized staging system for the clinical nodal staging of breast cancer can lead to diverse practice patterns. Thus, practical, harmonized, and objective methods for clinical nodal staging and for the outcomes of post-NST response are warranted for appropriate treatment decisions and accurate outcome evaluation.

Axillary response and outcome in breast cancer patients after neoadjuvant treatment: The role of radiotherapy in reducing recurrence in ypN0 patients with initially cN+ stage

Objective

We aim to explore the clinicopathological features associated with axillary node response and recurrence in breast cancer patients undergoing neoadjuvant treatment (NAT).

Methods

We retrospectively reviewed the medical records of 486 stage I to III breast cancer patients who received NAT and surgery between 2016 and 2021.

Results

A total of 486 cases were reviewed and 154 (31.7%) patients achieved breast pathological complete response (pCR) (ypT0/Tis). Of the 366 cases with initially cN+, 177 (48.4%) cases reach ypN0. Breast pCR is in high accordance to axillary pCR (81.5%). Hormone receptor (HR)-/HER2+ breast cancer patients have the highest axillary pCR rate (78.3%). Patients achieve axillary pCR have a significantly better disease-free survival (DFS) (P=0.0004). Further analysis reveals that the DFS of ypN0 and ypN1 cases are similar (P=0.9049). Moreover, DFS in patients with ypN0 (P&lt;0.0001) and ypN1 (P&lt;0.0001) is significantly better than that in patients with ypN2-3. For post-mastectomy ypN0 cases, radiation could only improve DFS in patients with initially cN+ stage (P=0.0499). Multivariate Cox regression analysis shows that radiation is an independent factor to improve DFS (Hazard ratio (HR): 0.288(0.098-0.841), P=0.0230). Radiation does not improve DFS in pre-cN0/ypN0 patients (P=0.1696).

Conclusion

Axillary pCR rate is higher than breast pCR rate. HR-/HER2+ patients have the highest axillary pCR rate. Axillary pCR is associated with better DFS. Radiation could further improve DFS in ypN0 patients with initially positive nodal disease.

Level I axillary dissection in patients with breast cancer and tumor-involved sentinel lymph node after NAC is not sufficient for adequate nodal staging

Objectives

The purpose of the study was to investigate the oncological sufficiency of level I axillary dissection for adequate histological nodal staging (ypN) in patients with breast cancer and tumor-involved sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC).

Material and Methods

A prospective multicentre pilot study took place from 01.01.2018 to 30.11.2020 in three mammary centres in the Czech Republic in patients with breast cancer after NAC (NCT03556397). Patients in the cohort with positive histological frozen section of SLN were indicated to separate axillary dissection of levels I and II.

Results

Sixty-one patients with breast cancer after NAC were included in the study according to inclusion and exclusion criteria. Twelve patients with breast cancer and tumour involved SLN after NAC were further included in the analysis. Two (16.7%) patients had positive non-sentinel lymph nodes in level I only, one (8.3%) patient had positive lymph nodes in level II only, and seven (58.3%) patients had positive lymph nodes in both levels. Level I axillary dissection in a patient with tumour involved SLN after NAC would have resulted in understaging in five (41.7%) patients, mostly ypN1 instead of ypN2.

Conclusion

According to our pilot result, level I axillary dissection is not sufficient in terms of adequate histological nodal staging in breast cancer patients after NAC, and level II axillary dissection should not be omitted.

De-Escalating Axillary Surgery in Node-Positive Breast Cancer Treated with Neoadjuvant Systemic Therapy

Background

There is a trend towards de-escalating axillary staging and treatment in breast cancer patients. On account of neoadjuvant systemic therapy, node-positive breast cancer patients can achieve a pathological complete response of the axilla. It is hypothesized that these patients do not benefit from an axillary lymph node dissection (ALND), and thus may be spared the risk of severe post-surgical morbidity. In an effort to omit standard ALND, less invasive axillary staging procedures are being implemented to establish response-guided treatment. However, it is unclear which less invasive staging procedure is most accurate, and long-term data are missing with regard to their oncologic safety.

Summary

This article provides an overview of the literature on currently used less invasive axillary staging procedures, the accuracy and feasibility of these procedures in clinical practice, important issues concerning axillary treatment, and issues to be addressed in ongoing or future studies.

Key messages

More evidence is needed regarding the safety of replacing standard ALND by less invasive axillary staging procedures in terms of long-term prognosis. These less invasive staging procedures not only serve to select patients who may benefit from treatment de-escalation, but also to select patients who may benefit from treatment escalation.

Value of 18F-FDG PET/CT for predicting axillary pathologic complete response following neoadjuvant systemic therapy in breast cancer patients: emphasis on breast cancer subtype

Background

Neoadjuvant systemic therapy (NST) is a widely accepted initial treatment modality that can lead to pathologic downstaging of the axillary disease burden in breast cancer patients. Axillary response as well as baseline ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake on positron emission tomography with computed tomography (PET/CT) differ between breast cancer subtypes. The value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST is not yet established, possibly since breast cancer subtype was not taken into account. The purpose of this study was to investigate the value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST with a specific emphasis on subtype.

Methods

PET-parameters derived from the primary tumor as well as the most FDG-avid axillary lymph node were measured on baseline ¹⁸F-FDG PET/CT. Overall imaging findings were compared with the gold standard of histopathology of the axillary surgery specimen. Analyses for ER-positive/HER2-negative were performed separately from HER2-positive and TN patients. In addition, separate analyses for clinically node-positive patients were performed.

Results

Sixty-six patients with 69 primary tumors were included in this study. Thirty-three axillae contained ER-positive/HER2-negative, 16 HER2-positive, and 20 TN breast cancer. No significant difference in PET-parameters between patients with axillary residual disease and axillary pathologic complete response were found for ER-positive/HER2-negative breast cancer. In the combined HER2-positive/TN subgroup, the SUV_max was significantly lower in patients without residual axillary disease in both the entire cohort and in patients with clinically node-positive disease. In this combined subgroup, a cut-off of 4.89 SUV_max measured on the most FDG-avid axillary lymph node could predict residual axillary disease with a sensitivity, specificity, PPV, and NPV of 90%, 69%, 53%, and 95%, respectively.

Conclusions

Predicting axillary response following NST with baseline ¹⁸F-FDG PET/CT can be performed when focusing on breast cancer subtypes. The easily computed PET-parameter SUV_max can predict axillary response in HER2-positive and TN breast cancer. This study adds to the accumulating evidence that studies investigating the value of ¹⁸F-FDG PET/CT in breast cancer should always take subtypes into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00861-z.

MINImal vs. MAXimal Invasive Axillary Staging and Treatment After Neoadjuvant Systemic Therapy in Node Positive Breast Cancer: Protocol of a Dutch Multicenter Registry Study (MINIMAX)

BACKGROUND

Node positive breast cancer (cN+) patients with an axillary pathologic complete response after neoadjuvant systemic therapy (NST) are not expected to benefit from axillary lymph node dissection (ALND). Therefore, less invasive axillary staging procedures have been introduced to establish response-guided treatment. However, evidence is lacking with regard to their oncologic safety and impact on quality of life (QoL). We hypothesize that if response-guided treatment is given, less invasive staging procedures are non-inferior to standard ALND in terms of oncologic safety, and superior to standard ALND in terms of QoL.

PATIENTS AND METHODS

MINIMAX is a Dutch multicenter registry study that includes patients with cN1-3M0 unilateral invasive breast cancer, who receive NST, followed by axillary staging and treatment according to local protocols. In a retrospective registry of ±4000 patients, the primary endpoint is oncologic safety at 5 and 10 years (disease-free, breast-cancer-specific and overall survival, and axillary recurrence rate). In a prospective multicenter registry, the primary endpoints are QoL at 1 and 5 years, and we aim to verify the 5-year oncologic safety. With an estimated 5-year disease-free survival of 72.5% and anticipated loss to follow-up of 10%, a sample size of 549 is needed to have 80% power to detect non-inferiority (with a 10% margin) of less invasive staging procedures.

CONCLUSION

In cN+ patients treated with NST, less invasive axillary staging procedures are already implemented globally. Evidence is needed to support the assumed oncologic safety and superior QoL of such procedures. This study will contribute to evidence-based guidelines.