Is axillary imaging for invasive lobular carcinoma accurate in determining clinical node staging?

Is routine axillary lymph node dissection needed to tailor systemic treatments for breast cancer patients in the era of molecular oncology? A position paper of the Italian National Association of Breast Surgeons (ANISC)

BACKGROUND

De-escalation of axillary surgery in breast cancer (BC) management began when sentinel lymph node biopsy (SLNB) replaced axillary lymph node dissection (ALND) as standard of care in patients with node-negative BC. The second step consolidated ALND omission in selected subgroups of BC patients with up to two macrometastases and recognized BC molecular and genomic implication in predicting prognosis and planning adjuvant treatment. Outcomes from the recent RxPONDER and monarchE trials have come to challenge the previous cut-off of two SLN in order to inform decisions on systemic therapies for hormone receptor-positive (HR+), human epidermal growth factor receptor type-2 (HER2) negative BC, as the criteria included a cut-off of respectively three and four SLNs. In view of the controversy that this may lift in surgical practice, the Italian National Association of Breast Surgeons (Associazione Nazionale Italiana Senologi Chirurghi, ANISC) reviewed data regarding the latest trials on this topic and proposes an implementation in clinical practice.

MATERIAL AND METHODS

We reviewed the available literature offering data on the pathological nodal status of cN0 breast cancer patients.

RESULTS

The rates of pN2 status in cN0 patients ranges from 3.5 % to 16 %; pre-surgical diagnostic definition of axillary lymph node status in cN0 patients by ultrasound could be useful to inform about a possible involvement of ≥4 lymph nodes in this specific sub-groups of women.

CONCLUSIONS

The Italian National Association of Breast Surgeons (ANISC) considers that for HR + HER2-/cN0-pN1(sn) BC patients undergoing breast conserving treatment the preoperative workup should be optimized for a more detailed assessment of the axilla and the technique of SLNB should be optimized, if considered appropriate by the surgeon, not considering routine ALND always indicated to determine treatment recommendations according to criteria of eligibility to RxPONDER and monarch-E trials.

High-accuracy prediction of axillary lymph node metastasis in invasive lobular carcinoma using focal cortical thickening on magnetic resonance imaging

BACKGROUND

Invasive lobular carcinoma (ILC) grows diffusely in a single-cell fashion, sometimes presenting only subtle changes in preoperative imaging; therefore, axillary lymph node (ALN) metastases of ILC are difficult to detect using magnetic resonance imaging (MRI). Preoperative underestimation of nodal burden occurs more frequently in ILC than in invasive ductal carcinoma (IDC), however, the morphological assessment for metastatic ALNs of ILC have not fully been investigated. We hypothesized that the high false-negative rate in ILC is caused by the discrepancy in the MRI findings of ALN metastases between ILC and IDC and aimed to identify the MRI finding with a strong correlation with ALN metastasis of ILC.

METHOD

This retrospective analysis included 120 female patients (mean ± standard deviation age, 57.2 ± 11.2 years) who underwent upfront surgery for ILC at a single center between April 2011 and June 2022. Of the 120 patients, 35 (29%) had ALN metastasis. Using logistic regression, we constructed prediction models based on MRI findings: primary tumor size, focal cortical thickening (FCT), cortical thickness, long-axis diameter (LAD), and loss of hilum (LOH).

RESULTS

The area under the curves were 0.917 (95% confidence interval [CI] 0.869-0.968), 0.827 (95% CI 0.758-0.896), 0.754 (95% CI 0.671-0.837), and 0.621 (95% CI 0.531-0.711) for the FCT, cortical thickness, LAD, and LOH models, respectively.

CONCLUSIONS

FCT may be the most relevant MRI finding for ALN metastasis of ILC, and although its prediction model may lead to less underestimation of the nodal burden, rigorous external validation is required.

Development and validation of a pre- and intra-operative scoring system that distinguishes between non-advanced and advanced axillary lymph node metastasis in breast cancer with positive sentinel lymph nodes: a retrospective study

Background

There are currently no scoring-type predictive models using only easily available pre- and intraoperative data developed for assessment of the risk of advanced axillary lymph node metastasis (ALNM) in patients with breast cancer with metastatic sentinel lymph nodes (SLNs). We aimed to develop and validate a scoring system using only pre- and intraoperative data to distinguish between non-advanced (≤ 3 lymph nodes) and advanced (> 3 lymph nodes) ALNM in patients with breast cancer with metastatic SLNs.

Methods

We retrospectively identified 804 patients with breast cancer (cT1-3cN0) who had metastatic SLNs and had undergone axillary lymph node dissection (ALND). We evaluated the risk factors for advanced ALNM using logistic regression analysis and developed and validated a scoring system for the prediction of ALNM using training (n = 501) and validation (n = 303) cohorts, respectively. The predictive performance was assessed using the receiver operating characteristic (ROC) curve, area under the curve (AUC), and calibration plots.

Results

Ultrasound findings of multiple suspicious lymph nodes, SLN macrometastasis, the ratio of metastatic SLNs to the total number of SLNs removed, and the number of metastatic SLNs were significant risk factors for advanced ALNM. Clinical tumor size and invasive lobular carcinoma were of borderline significance. The scoring system based on these six variables yielded high AUCs (0.90 [training] and 0.89 [validation]). The calibration plots of frequency compared to the predicted probability showed slopes of 1.00 (training) and 0.85 (validation), with goodness-of-fit for the model. When the cutoff score was set at 4, the negative predictive values (NPVs) of excluding patients with advanced ALNM were 96.8% (training) and 96.9% (validation). The AUC for predicting advanced ALNM using our scoring system was significantly higher than that predicted by a single independent predictor, such as the number of positive SLNs or the proportion of positive SLNs. Similarly, our scoring system also showed good discrimination and calibration ability when the analysis was restricted to patients with one or two SLN metastases.

Conclusion

Our easy-to-use scoring system can exclude advanced ALNM with high NPVs. It may contribute to reducing the risk of undertreatment with adjuvant therapies in patients with metastatic SLNs, even if ALND is omitted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02779-9.

Invasive Lobular Breast Cancer: Data to Support Surgical Decision Making

BACKGROUND

Invasive lobular carcinoma (ILC) is thought be a unique entity with higher rates of multifocal/multicentric and bilateral disease. This study aimed to evaluate the true extent of the disease, risk of bilaterality, lymph node involvement, and impact of preoperative imaging to help guide surgical decision making.

METHODS

A retrospective analysis identified patients treated for ILC between 2004 and 2017. Clinical staging and pathologic results were compared. Follow-up details including local recurrence, contralateral breast cancer (CBC), and survival outcomes were evaluated.

RESULTS

The study identified 692 patients with ILC, including 43 patients (6%) with a diagnosis of CBC and 232 patients (33%) with a diagnosis of multifocal/multicentric disease at presentation. Preoperative magnetic resonance imaging (MRI) led to an identification of additional disease in 20% of the patients. Preoperative MRI resulted in a more accurate prediction of tumor size staging but did not improve the discordance between clinical and pathologic nodal staging. Overall, the rate of imaging occult lymph node disease was 24%. At the 6-year follow-up evaluation, a local recurrence had developed in 2.3%, a CBC in 2.3, and a distant metastasis in 9.4% of the patients. The overall survival rate was 96% at 3 years and 91% at 5 years.

CONCLUSIONS

Invasive lobular carcinoma is a distinct subset of cancer that poses a diagnostic staging challenge. The results of this study favor MRI for accurate tumor staging and for improving detection of multicentricity and bilaterality. However, clinicians should be aware of the higher likelihood of occult lymph node involvement with ILC and subsequent early metastasis.

Is image-guided core needle biopsy of borderline axillary lymph nodes in breast cancer patients clinically helpful?

BACKGROUND

When borderline axillary lymph nodes (bALN) are identified on ultrasound (US) for breast cancer (BC) patients, preoperative management is unclear. We aimed to evaluate if core needle biopsy (CNB) for bALN is clinically helpful or disruptive.

METHODS

Retrospective review of BC patients with bALN from 2014 to 2019 was performed. Clinicopathologic data were compared for those who did and did not have CNB.

RESULTS

CNB (n = 34) and no CNB (n = 31) were similar with respect to clinicopathologic factors. Surgical LN-positive rate was the same between cohorts (p = 0.26). CNB was disruptive in 58.8 %; all had CNB for pN0 disease. CNB was helpful in 34.2 %: 14.7 % proceeded directly to axillary dissection; 17.6 % had positive LN localized after neoadjuvant chemotherapy.

CONCLUSIONS

CNB for bALN is more likely clinically disruptive and did not impact surgical LN positive rate. BC patients with bALN should undergo CNB only if it will change clinical management.