Validated prediction model for positive resection margins in breast-conserving surgery based exclusively on preoperative data

Pushing the envelope in breast conserving surgery - is multiple-wire localization (3 or more wires) associated with increased risk of compromised margins and long-term recurrence?

INTRODUCTION

In the last two decades there has been a paradigm shift with breast conserving surgery (BCS) being applied to larger and more extensive breast malignancies. The aim of this study is to examine the success of BCS being performed in patients with extensive breast malignancies requiring at least 3 wires for localization, and to assess possible risk factors for failure.

MATERIALS AND METHODS

We performed a retrospective single center review of 232 patients who underwent BCS between 2010 and 2020 requiring at least 3 wires for localization, thus comprising the multi-wire group (MWG). The cohort included a control group of 232 single-wire BCS patients (SWG) chronologically matched with the MWG. Patients with either invasive malignancy or ductal carcinoma in situ (DCIS) were included in the study. Clinical, radiological, and pathological data was collected. Proportions of positive surgical margins, re-lumpectomies and conversion to mastectomy were calculated. Survival analysis for locoregional and distant recurrence was performed.

RESULTS

Women in the MWG were younger (mean age 57 vs. 63.1, P < 0.001), had larger tumor size (mean size 5.1 cm vs. 1.3 cm, p < 0.001), a higher prevalence of calcifications on mammograms (72 % vs. 17 %, P < 0.001), a higher proportion of positive lymph nodes (75 % vs. 45 %, P = 0.019), and an elevated incidence of a ductal carcinoma in situ (DCIS) component (72 % vs. 38 %, P < 0.001). Positive surgical margins were higher in the MWG (13 % vs 7 %, P = 0.03), which lead to higher proportions of re-lumpectomies or conversion to mastectomies (7 % vs 4 %, P = 0.17). On multivariate analysis of the entire cohort, patients with positive margins were more likely to have a DCIS component (77 % vs 53 %, P = 0.001), an infiltrating lobular carcinoma (ILC) component (15 % vs 9 %, P = 0.013), and positive ER hormonal status (94 % vs 85 %, p = 0.05). The number of wires was not an independent predictor of positive margins. On long-term analysis, the locoregional disease-free survival was similar between the SWG and MWG (P = 0.1). However, the MWG showed higher rates of distant metastasis (12 % vs 4 %, P = 0.006).

CONCLUSIONS

BCS requiring 3 or more wires is associated with a slightly higher proportion of positive margins. The increased risk of positive margins appears to be related to the type of tumor (DCIS component, ILC component and ER status) rather than to the number of wires. The number of wires does not significantly impact locoregional disease-free survival.

Digital breast tomosynthesis versus X-ray of the breast specimen for intraoperative margin assessment: A randomized trial

BACKGROUND

Involved resection margins after breast conserving surgery (BCS) often require a re-operation with increased patient anxiety and risk of impaired cosmesis. We investigated the number of re-operations due to involved resection margins after BCS comparing digital breast tomosynthesis(DBT) with X-ray for intraoperative margin evaluation. Furthermore, we assessed the diagnostic accuracy of these methods to predict histopathological margin status. Finally, we evaluated risk factors for re-operation.

METHODS

In this randomized, non-blinded study, 250 invasive breast cancer patients were randomized (1:1), whereof 241 were analyzed intraoperatively with either DBT (intervention, n = 119) or X-ray (standard, n = 122). Pearson's chi-squared test, Fisher's exact test, t-test, logistic and ordinal regression analysis was used as appropriate.

RESULTS

No difference was found in the number of re-operations between the DBT and X-ray group (16.8 % vs 19.7 %, p = 0.57), or in diagnostic accuracy to predict histopathological margin status (77.5 %, CI: 68.6-84.9 %) and (67.3 %, CI: 57.7-75.9 %), respectively. We evaluated 5 potential risk factors for re-operation: Ductal carcinoma in situ (DCIS) outside tumor, OR = 9.4 (CI: 4.3-20.6, p < 0.001); high mammographic breast density, OR = 6.1 (CI: 1.0-38.1, p = 0.047); non-evaluable margins on imaging, OR = 3.8 (CI: 1.3-10.8, p = 0.016); neoadjuvant chemotherapy, OR = 3.0 (CI: 1.0-8.8, p = 0.048); and T2 tumor-size, OR = 2.6 (CI: 1.0-6.4, p = 0.045).

CONCLUSIONS

No difference was found in the number of re-operations or in diagnostic accuracy to predict histopathological margin status between DBT and X-ray groups. DCIS outside the tumor showed the highest risk of re-operation. Intraoperative methods with improved visualization of DCIS are needed to obtain tumor free margins in BCS.

Blood flow on ultrasound imaging is a predictor of lump margin status in breast-conserving patients: a retrospective matching study

PURPOSE

This study investigated the relationship between breast ultrasound features and lump margin status in breast-conserving patients.

METHODS

A single-institution database and medical records system were searched to identify patients who had undergone breast-conserving surgery between 2015 and 2022. Patients were divided into case and control groups based on their postoperative margin status, and different matching methods [case-control matching (CCM) and propensity score matching (PSM)] were used to match the cases and controls at a ratio of 1:1.

RESULTS

Before matching, patients with positive margins were more likely to have a tumor with increased blood flow (OR = 2.90, 95% CI 1.83-4.61, p < 0.001) and microcalcifications (OR = 2.22, 95% CI 1.44-3.42, p < 0.001). Among the 83 pairs of CCM subjects, patients with positive margins were prone to increased blood flow (p = 0.007) and crab sign (p = 0.040). In addition, there was a significant difference in blood flow (p = 0.030) among PSM subjects. After adjusting for the unbalanced factors, the same results were obtained.

CONCLUSIONS

Ultrasound blood flow significantly predicts the status of breast-conserving margins, but further studies are required to verify our findings.

Evaluating the relevance of surgical margins. Part one: The problems with current methodology

The goal of cancer surgery is to achieve a "clean" microscopic resection, with no residual tumour remaining in the wound. To achieve that goal, the surgeon typically incorporates a measured buffer of grossly normal tissue about the entire circumference of the tumour. Microscopic analysis of the resection boundaries is then performed to determine if all traces of the tumour have been completely removed. This analysis is thought to provide a surrogate indication as to the likelihood for that tumour to recur after surgery. However, it is recognised that tumour recurrence may not occur even when microscopic evidence of tumour has been identified at the resection margins, and recurrence can also occur when conventional histology has considered the tumour to have been completely removed. The explanations for this dichotomy are numerous and include technical and practical limitations of the processing methodology, and also several surgeon-related and tumour-related reasons. Ultimately, the inability to confidently determine when a tumour has been removed sufficiently to prevent recurrence can impact on the ability to provide owners with confident treatment advice. In this article, the authors describe the challenges with defining the true extent of the tumour margin from the perspective of the surgeon, the pathologist and the tumour. The authors also provide an analysis of why our current efforts to ensure that all traces of the local tumour have been successfully removed may provide an imperfect assessment of the risk of recurrence.

Development and Validation of a Prediction Model for Positive Margins in Breast-Conserving Surgery

Background

The chances of second surgery due to positive margins in patients receiving breast-conversing surgery (BCS) were about 20-40%. This study aims to develop and validate a nomogram to predict the status of breast-conserving margins.

Methods

The database identified patients with core needle biopsy-proven ductal carcinoma in situ (DCIS) or invasive breast carcinoma who underwent BCS in Shanxi Bethune Hospital between January 1, 2015 and December 31, 2021 (n = 573). The patients were divided into two models: (1) The first model consists of 398 patients who underwent BCS between 2015 and 2019; (2) The validation model consists of 175 patients who underwent BCS between 2020 and 2021. The development of the nomogram was based on the findings of multivariate logistic regression analysis. Discrimination was assessed by computing the C-index. The Hosmer-Lemeshow goodness-of-fit test was used to validate the calibration performance.

Results

The final multivariate regression model was developed as a nomogram, including blood flow signals (OR = 2.88, p = 0.001), grade (OR = 2.46, p = 0.002), microcalcifications (OR = 2.39, p = 0.003), tumor size in ultrasound (OR = 2.12, p = 0.011) and cerbB-2 status (OR = 1.99, p = 0.042). C-indices were calculated of 0.71 (95% CI: 0.64-0.78) and 0.68 (95% CI: 0.59-0.78) for the modeling and the validation group, respectively. The calibration of the model was considered adequate in the validation group (p > 0.05).

Conclusion

We developed a nomogram that enables the estimation of the preoperative risk of positive BCS margins. Our nomogram provides a valuable tool for identifying high-risk patients who might have to undergo a wider excision.