Changes of breast and axillary surgery patterns in patients with primary breast cancer during the past decade

Can multi-modal radiomics using pretreatment ultrasound and tomosynthesis predict response to neoadjuvant systemic treatment in breast cancer?

OBJECTIVES

Response assessment to neoadjuvant systemic treatment (NAST) to guide individualized treatment in breast cancer is a clinical research priority. We aimed to develop an intelligent algorithm using multi-modal pretreatment ultrasound and tomosynthesis radiomics features in addition to clinical variables to predict pathologic complete response (pCR) prior to the initiation of therapy.

METHODS

We used retrospective data on patients who underwent ultrasound and tomosynthesis before starting NAST. We developed a support vector machine algorithm using pretreatment ultrasound and tomosynthesis radiomics features in addition to patient and tumor variables to predict pCR status (ypT0 and ypN0). Findings were compared to the histopathologic evaluation of the surgical specimen. The main outcome measures were area under the curve (AUC) and false-negative rate (FNR).

RESULTS

We included 720 patients, 504 in the development set and 216 in the validation set. Median age was 51.6 years and 33.6% (242 of 720) achieved pCR. The addition of radiomics features significantly improved the performance of the algorithm (AUC 0.72 to 0.81; p = 0.007). The FNR of the multi-modal radiomics and clinical algorithm was 6.7% (10 of 150 with missed residual cancer). Surface/volume ratio at tomosynthesis and peritumoral entropy characteristics at ultrasound were the most relevant radiomics. Hormonal receptors and HER-2 status were the most important clinical predictors.

CONCLUSION

A multi-modal machine learning algorithm with pretreatment clinical, ultrasound, and tomosynthesis radiomics features may aid in predicting residual cancer after NAST. Pending prospective validation, this may facilitate individually tailored NAST regimens.

CLINICAL RELEVANCE STATEMENT

Multi-modal radiomics using pretreatment ultrasound and tomosynthesis showed significant improvement in assessing response to NAST compared to an algorithm using clinical variables only. Further prospective validation of our findings seems warranted to enable individualized predictions of NAST outcomes.

KEY POINTS

• We proposed a multi-modal machine learning algorithm with pretreatment clinical, ultrasound, and tomosynthesis radiomics features to predict response to neoadjuvant breast cancer treatment. • Compared with the clinical algorithm, the AUC of this integrative algorithm is significantly higher. • Used prior to the initiative of therapy, our algorithm can identify patients who will experience pathologic complete response following neoadjuvant therapy with a high negative predictive value.

The Lucerne Toolbox 2 to optimise axillary management for early breast cancer: a multidisciplinary expert consensus

Clinical axillary lymph node management in early breast cancer has evolved from being merely an aspect of surgical management and now includes the entire multidisciplinary team. The second edition of the "Lucerne Toolbox", a multidisciplinary consortium of European cancer societies and patient representatives, addresses the challenges of clinical axillary lymph node management, from diagnosis to local therapy of the axilla. Five working packages were developed, following the patients' journey and addressing specific clinical scenarios. Panellists voted on 72 statements, reaching consensus (agreement of 75% or more) in 52.8%, majority (51%-74% agreement) in 43.1%, and no decision in 4.2%. Based on the votes, targeted imaging and standardized pathology of lymph nodes should be a prerequisite to planning local and systemic therapy, axillary lymph node dissection can be replaced by sentinel lymph node biopsy ( ± targeted approaches) in a majority of scenarios; and positive patient outcomes should be driven by both low recurrence risks and low rates of lymphoedema.

Long-term survival after sentinel lymph node biopsy or axillary lymph node dissection in pN0 breast cancer patients: a population-based study

PURPOSE

Findings from randomized clinical trials have shown that survival in patients with sentinel lymph node (SLN)-negative breast cancer is noninferior with SLN biopsy (SLNB) alone versus further axillary lymph node dissection (ALND). However, the long-term outcome of these two surgical approaches in pN0 breast cancer patients in real-world setting remains uncertain.

METHODS

We included patients diagnosed with pathologically staged T1-2N0M0 breast cancer between 2000 and 2015 in surveillance, epidemiology, and end results 18-registry database. Patients were considered to have undergone SLNB alone if they had ≤ 5 examined lymph nodes (ELNs), and ALND if they had ≥ 10 ELNs. The outcomes included overall survival (OS) and breast cancer-specific survival. Propensity score analyses by weighting and matching and multivariable Cox regression analysis were performed to minimize treatment selection bias.

RESULTS

We included 309,430 patients (253,501 SLNB and 55,929 ALND). In the weighted cohort, ALND was associated with significantly lower OS (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.10-1.16) and BCSS (HR 1.16; 95% CI 1.10-1.22) compared with SLNB alone. Both the propensity score-matching model and multivariable Cox model demonstrated a survival benefit for SLNB when compared with ALND. Subgroup analyses for key variables did not change these findings.

CONCLUSION

We found statistically significant differences in OS and BCSS between SLNB and ALND, though the magnitude of these differences was small. Our findings further support that SLNB alone should be the standard of care for patients who do not have metastatic lymph nodes identified during breast cancer surgery.

Extranodal extension, an international survey on its evaluation and reporting in breast cancer patients

Lymph node metastasis is the most important prognostic factor for breast cancer patients. In addition to the number of nodes involved and the largest metastatic focus, extranodal extension (ENE) is also used to subclassify breast cancer patients into different risk groups. More recently, pathologists are required to report the size/extent of ENE per the new CAP guideline, as it seems to be associated with more axillary nodal burden and/or a worse prognosis. Although the definition of ENE is largely understood and agreed upon among pathologists around the world, evaluation and reporting for the size of ENE are not. To understand current practice, we conducted an international survey among pathologists who are interested in breast pathology. A total of 70 pathologists responded. The results showed that (1) 98% of the participants reported the presence or absence of ENE and 61% also reported the size of ENE in millimeter (mm). (2) There was no uniform method of measuring the size of ENE; 47% measured the largest dimension regardless of orientation, while 30% measured the largest perpendicular distance from the capsule. (3) The most common factors affecting the accuracy in diagnosis of ENE are the presence of lymphovascular invasion (LVI), lack of capsule integrity, and the presence of fatty hilar or fatty replacement of a lymph node. (4) 71% felt that the H&E stain is adequate to evaluate ENE, deeper levels and IHC analysis for vascular and cytokeratin markers can be helpful if needed. (5) 75% agreed that there is an urgent need to standardize the measurement and reporting for ENE. Our survey highlights the variation in ENE evaluation and the need for its standardization in breast cancer patients with axillary node metastasis.

Imaging Evaluation of the Axilla-A National Survey of Clinical Practice Among Radiologists

OBJECTIVE

To assess awareness and implementation of the American College of Surgeons Oncology Group Z0011 trial findings, approaches to axillary nodal imaging, and to identify differences in practice based on respondent characteristics.

METHODS

An online survey was distributed to members of the Society of Breast Imaging. Questions regarded demographics, evaluation approaches, and impact of the Z0011 trial. Poisson regression with robust standard errors to regression was used to generate multivariable-adjusted relative risks and 95% confidence intervals (CIs) for associations.

RESULTS

The response rate was 21.7% (430/2007). The majority (295/430, 68.6%) reported always performing axillary US in patients with a BI-RADS 4B, 4C, or 5 breast mass. Most respondents (299/430, 69.5%) were familiar with the findings of the Z0011 trial. Radiologists in academic practice were 0.67 (95% CI: 0.54-0.83) times less likely than private practice radiologists to perform axillary US in all masses and 1.31 (95% CI: 1.13-1.52) times more likely to be very familiar with the trial. Frequency of axillary US showed no association with time spent in breast imaging, years in practice, or presence of dedicated breast surgeons. Increased time in breast imaging and presence of dedicated breast surgeons was strongly associated with familiarity with the trial. No association was observed with years in practice. Most respondents (291/430, 67.7%) made little or no change to their practice based on trial findings.

CONCLUSION

There is wide variability in approaches to axillary nodal evaluation, demonstrating a need for improved education and guidelines for axillary imaging in breast cancer patients.

Analyzing non-sentinel axillary metastases in patients with T3-T4 cN0 early breast cancer and tumor-involved sentinel lymph nodes undergoing breast-conserving therapy or mastectomy

Purpose

In the ACOSOG Z0011 trial, completing axillary lymph node dissection (cALND) did not benefit patients with T1–T2 cN0 early breast cancer and 1–2 positive sentinel lymph nodes (SLN) undergoing breast-conserving surgery (BCT). This paper reports cALND rates in the clinical routine for patients who had higher (T3–T4) tumor stages and/or underwent mastectomy but otherwise met the ACOSOG Z0011 eligibility criteria. Aim of this study is to determine cALND time trends and non-sentinel axillary metastases (NSAM) rates to estimate occult axillary tumor burden.

Methods

Data were included from patients treated in 179 German breast cancer centers between 2008 and 2015. Time-trend rates were analyzed for cALND of patients with T3–T4 tumors separated for BCT and mastectomy and regarding presence of axillary macrometastases or micrometastases.

Results

Data were available for 188,909 patients, of whom 19,009 were identified with 1–2 positive SLN. Those 19,009 patients were separated into 4 cohorts: (1) Patients with T1–T2 tumors receiving BCT (ACOSOG Z0011 eligible; n = 13,741), (2) T1–T2 with mastectomy (n = 4093), (3) T3–T4 with BCT (n = 269), (4) T3–T4 with mastectomy (n = 906). Among patients with T3–T4 tumors, cALND rates declined from 2008 to 2015: from 88.2 to 62.6% for patients receiving mastectomy and from 96.6 to 58.1% in patients receiving BCT. Overall rates for any NSAM after cALND for cohorts 1–4 were 33.4%, 42.3%, 46.9%, 58.8%, respectively.

Conclusions

The cALND rates have decreased substantially in routine care in patients with ‘extended’ ACOSOG Z0011 eligibility criteria. Axillary tumor burden is higher in these patients than in the ACOSOG Z0011 trial.

The Value of Repeated Breast Surgery as a Quality Indicator in Breast Cancer Care

Breast-conserving surgery, a major achievement in surgical oncology, has allowed an increasing number of breast cancer patients to avoid the mutilation of mastectomy. However, mastectomy still is performed in certain circumstances although breast-conserving surgery would be equally safe. Many reasons, including patients' and surgeons' personal motivations, influence the decision-making process before the final choice between breast preservation and mastectomy. The importance of quality measurement and reporting in medicine is increasingly recognized, and breast surgery is no exception. The substantial variability of re-excision rates for positive surgical margins after a first attempt at breast-conserving surgery suggests that improvement is possible. Therefore, the re-excision rate has been proposed as a quality metric for assessing and comparing the performance of different institutions. Indeed, re-excision rates can be reduced by actionable factors such as accurate preoperative local staging, localization of occult lesions, and intraoperative assessment of the oriented specimen. However, equally important non-actionable risk factors pertaining the biology, detectability, and resectability of the tumor also should be taken into account. Therefore, if the re-excision rate has to be used as a performance indicator of breast surgical care, critical interpretation of results with accurate case-mix adjustment are mandatory, and reasonable targets must be appropriately set so that surgeons treating patients at higher risk of positive margins are not unduly penalized.

Accuracy of Sentinel Lymph Node Biopsy in Breast Cancer: Pitfalls in the Application of Single Tracers

Background

Radioisotopes and blue dyes are used as dual tracers in the current gold standard procedure of sentinel lymph node (SLN) biopsy (SLNB) performed for breast cancer. However, the blue dye or the radioisotope as a single tracer is also being applied in some institutes. We aimed to explore the risk factors for the miss-detection of SLNs with the radioisotope and the blue dye and to describe the distribution of SLNs missed by each tracer.

Patients and Methods

Patients undergoing SLNB with radioisotope and blue dye as dual mapping agents were enrolled between August 2010 and August 2018. Radioactivity count, blue dye staining status, and size and location of each SLN were prospectively documented.

Results

In total, 2382 SLNs from 1010 patients were included for statistical analyses. The sentinel node identification rate was 100% for dual tracers, 99.4% for radioisotope, and 89.1% for blue dye. SLN identification using the blue dye was more likely to fail in patients undergoing breast-conserving surgery (p < 0.001) and mastectomy with reconstruction (p = 0.005). Furthermore, miss-detection was significantly more frequent in smaller and uninvolved nodes. Among all SLNs, 8.2% were located in level II and one was in level III. Notably, single tracer of blue dye tended to fail in the detection of lymph nodes in higher levels (p < 0.001).

Conclusion

This study explored the association between features and the incidence of the failure to detect SLNs using radioisotope and blue dye. The locations of the miss-detected SLNs are demonstrated to provide a reference for SLNBs conducted using blue dye or radioisotope as a single tracer.

Increase of sentinel lymph node melanoma staging in The Netherlands; still room and need for further improvement

Aim:

To investigate implementation of the seventh American Joint Committee on Cancer melanoma staging with sentinel lymph node biopsy (SLNB) and associations with socioeconomic status (SES).

Patients & methods:

Data from The Netherlands Cancer Registry on patient and tumor characteristics were analyzed for all stage IB–II melanoma cases diagnosed 2010–2016, along with SES data from The Netherlands Institute for Social Research.

Results:

The proportion of SLNB-staged patients increased from 40% to 65% (p < 0.001). Multivariate analysis showed that being female, elderly, or having head-and-neck disease reduced the likelihood of SLNB staging.

Conclusion:

SLNB staging increased by 25% during the study period but lagged among elderly patients and those with head-and-neck melanoma. In The Netherlands, SES no longer affects SLNB staging performance.