Factors associated with residual disease after initial breast-conserving surgery for ductal carcinoma in situ

Is the Number or Proximity of Margins Less than 2 mm Associated with an Increased Mastectomy Rate in Patients Attempting Breast Conservation Therapy for Ductal Carcinoma In Situ?

BACKGROUND

Consensus guidelines recommend ≥ 2 mm margins in patients undergoing partial mastectomy (PM) for ductal carcinoma in situ (DCIS). It is unknown whether the number or proximity of margins less than 2 mm is associated with an increased mastectomy rate in patients attempting breast conservation therapy (BCT) for DCIS. The aim of this study is to examine this relationship.

PATIENTS AND METHODS

An institutional database review identified 208 patients with DCIS who underwent PM at a tertiary referral center and community hospitals from July 2020 to June 2023. Patients with a history of breast cancer, previous surgery for breast cancer, ipsilateral invasive carcinoma, papillary carcinoma, Paget's disease, more lobular carcinoma in situ (LCIS) than DCIS present, initial mastectomy, no DCIS present, routine shave margins (of all vectors), and ≥ 2 mm margins of all six vectors were excluded. Selective intraoperative margin re-excisions were included.

RESULTS

A total of 208 patients who met inclusion criteria were retrospectively reviewed. 122 (25%) had one close/positive (< 2 mm) margin and 86 (18%) had two or more close/positive margins. Of the patients with one close/positive margin, 7% (9/122) eventually underwent mastectomy. Of the patients with two or more close/positive margins, 20% (17/86) eventually underwent mastectomy. Overall, no patients with opposing margins underwent mastectomy.

CONCLUSIONS

Patients undergoing PM for DCIS have a mastectomy rate that is increased threefold, with two or more close/positive margins at initial PM, when compared with those with only one close/positive margin. The presence of opposing close/positive margins at initial PM did not increase the mastectomy rate and most were cleared with re-excision.

Predictors of residual disease after breast conservation surgery for ductal carcinoma in situ: A retrospective study

BACKGROUND

Breast-conserving therapy is the standard of care for ductal carcinoma in situ (DCIS). Debate on what constitutes a satisfactory margin persists. This study aimed to identify predictors of residual disease at re-excision.

METHODS

This is a population-based retrospective cohort study of women with DCIS who underwent a lumpectomy between 2007 and 2017 in Manitoba, with close (≤2 mm) or positive margins that led to re-excision.

RESULTS

The DCIS re-excision rate was 29.3% for 1001 patients. 63.2% of patients were found to have residual disease on re-excision. On univariable analysis, the size, margin status, number of positive margins, type of second surgery, and Van Nuys Prognostic Index score were associated with residual disease on re-excision. The size of DCIS and the number of positive margins remained statistically significant on multivariable analysis.

CONCLUSIONS

Re-excision should be rationalized by considering the predictors of residual disease in conjunction with other factors.

Rate of residual tumor after repeat surgery for positive margins in ductal carcinoma in Situ, and predictive factors

AIMS

To evaluate the rate of residual tumor in re-excision specimen of patients with positive margins in ductal carcinoma in situ (DCIS) following breast-conservative surgery, and to identify predictive factors of residual tumor.

MATERIAL AND METHODS

We conducted a monocentric, retrospective study, from January 2010 to December 2020. All 103 patients who underwent re-excision for positive margins in DCIS following breast-conservative surgery for in situ or invasive breast carcinoma were included. Positive margins were defined as inferior to 2 mm from the DCIS component. Two groups were defined, depending on the presence of residual tumor or not, and were compared on their clinical and histopathological characteristics to identify predictive factors of residual tumor.

RESULTS

Residual tumor was found in re-excision specimen of 46 patients (44.7 %). The risk of residual tumor was increased in patients with more than 2 tumor foci (aOR: 12.4; 95 % CI: 1.2 -124.1; p = 0.032) and in those with extensive margin involvement (aOR: 3.2; 95 % CI: 1.3-8.2; p = 0.013). Finally, surgery performed after 2013 was associated with a lower risk of residual tumor (aOR: 0.23; 95 % CI: 0.09-0.058; p = 0.002).

CONCLUSION

The rate of residual tumor in re-excision specimen of patients with positive margins in DCIS is high. Both the number of tumor foci and the extension of positive margins were identified as risk factors. Finally, the surgical learning curve for this procedure seems to be significantly correlated with the risk of residual tumor and needs to be considered.

Surgical management of ductal carcinoma in situ of the breast: A large retrospective study from a single institution

BACKGROUND

Management of breast ductal carcinoma in situ (DCIS) has various approaches with distinct institutional specific practice. Here, we review DCIS management in a single institution with emphasize on re-operation rates and outcome.

METHODS

Breast ductal carcinoma in situ cases diagnosed at the Nottingham Breast Institute between 1987 and 2017 were identified (n = 1249). Clinicopathological data were collected. Cases were histologically reviewed, and different factors associated with primary operation selection, re-excision, presence of residual tumor in the re-excision specimens, use of radiotherapy and ipsilateral recurrences were analyzed.

RESULTS

34% of DCIS patients were initially treated by mastectomy and were more frequently symptomatic, of high nuclear tumor grade, size >40 mm, and associated with comedo necrosis and Paget's disease of the nipple. Further surgery was due to involved or narrow surgical margins. Residual tumor tissue was detected in 53% of the re-excision specimens. Re-excision rates of patients treated with breast-conserving surgery (BCS) were reduced from approximately 70% to 23%, and the final mastectomy rates decreased from 60% to 20%. Changes in surgical practice with acceptance of smaller excision margins and more frequent use of local radiotherapy have led to a significant decrease not only in the re-excision rate but also in the final mastectomy rate together with non-significant reduction in 5- and 10-year local recurrence rates.

CONCLUSION

Although BCS is increasingly the preferred primary surgical option for DCIS management, a proportion of low-risk DCIS patients continue to undergo re-excision surgery or completion mastectomy. Despite acceptance of smaller margins, recurrence rate is decreasing.

Accuracy of Breast Magnetic Resonance Imaging Compared to Mammography in the Preoperative Detection and Measurement of Pure Ductal Carcinoma In Situ: A Retrospective Analysis

RATIONALE AND OBJECTIVES

Ductal carcinoma in situ (DCIS) hinders imaging detection due to multifocal appearance and discontinuous growth. Preoperative determination of its extent is therefore challenging. Aim of this study was to investigate the additional benefit of breast magnetic resonance imaging (MRI) to mammography (MG) in the diagnosis of DCIS according to size and grading.

MATERIALS AND METHODS

Retrospective analysis of 295 patients with biopsy-proven, pure DCIS. Mean patient age was 57.0 years (27-87 years). All patients obtained MG. Additional MRI was performed in 41.7% (123/295). Mammographic breast density, background parenchymal enhancement (BPE), tumor size and grading were analysed. Tumor size on MG and MRI were compared to histopathological size of the surgical specimen.

RESULTS

Mean tumor size was 39.6 mm. DCIS was occult on MG in 24.4% (30/123) and on MRI in 1.6% (2/123). Size was underestimated by 4.6 mm (mean) mammographically. DCIS was high grade in 54.5% (67/123), intermediate grade in 40.7% (50/123) and low grade in 4.9% (6/123). MG was exact regarding tumor size in low grade DCIS, underestimated intermediate grade DCIS by 1 mm (median) and high grade DCIS by 10.5 mm. MRI overestimated low grade DCIS by 1 mm (median), was exact regarding intermediate grade DCIS and underestimated high grade DCIS by 1 mm. BPE did not influence tumor detection and measurement.

CONCLUSION

MRI outperforms MG in the detection and size estimation of DCIS and can reduce positive margin rates.

Repeated surgeries in invasive lobular breast cancer with preoperative MRI: Role of additional carcinoma in situ and background parenchymal enhancement

OBJECTIVES

Analysing the influence of additional carcinoma in situ (CIS) and background parenchymal enhancement (BPE) in preoperative MRI on repeated surgeries in patients with invasive lobular carcinoma (ILC) of the breast.

METHODS

Retrospective analysis of 106 patients (mean age 58.6±9.9years) with 108 ILC. Preoperative tumour size as assessed by MRI, mammography and sonography was recorded and compared to histopathology. In contrast-enhanced MRI, the degree of BPE was categorised by two readers. The influence of additionally detected CIS and BPE on the rate of repeated surgeries was analysed.

RESULTS

Additional CIS was present in 45.4% of the cases (49/108). The degree of BPE was minimal or mild in 80% of the cases and moderate or marked in 20% of the cases. In 17 cases (15.7%) at least one repeated surgery was performed. In n=15 of these cases, repeated surgery was performed after BCT (n=9 re-excisions, n=6 conversions to mastectomy), in n=2 cases after initial mastectomy. The initial surgical procedure (p=0.008) and additional CIS (p=0.046) significantly influenced the rate of repeated surgeries, while tumour size, patient age and BPE did not (p=ns).

CONCLUSIONS

Additional CIS was associated with a higher rate of repeated surgeries, whereas BPE had no influence.

Reexcision for positive margins in breast cancer: A predictive score of residual disease

BACKGROUND

Guidelines recommend re-excision if resection margins are positive in lumpectomy for breast cancer. However, residual disease (RD) is not always found. The aim of our study was to develop a score to predict RD in re-excision specimens.

MATERIALS AND METHODS

We carried out a multicenter, retrospective study with two population groups. The 'modeling' group was composed of 148 patients treated in the Centre Hospitalier Poissy-St-Germain or the Georges Pompidou European Hospital and the 'validation' group was composed of 67 patients treated in Curie Institute. The score was built with a logistic regression model.

RESULTS

Factors independently associated with RD were: a cumulative length of all positive margins>5 mm, invasion by ductal carcinoma in situ only, a pathological tumor size>30 mm and a pathological tumor size<30 mm with a discrepancy of >50% between pathological and radiological tumor size. The 7-point score allowed the classification of patients into three risk groups for RD: low (16% of patients experienced RD), moderate (65%) and high (100%). The areas under the ROC curve of the score and the logistic model were 0.72(95%CI:0.68-0.75,p = 0.60). The proportion of RD in each group of the validation population (25%, 48%, and 100% in the low, moderate and high group, respectively) confirmed the accuracy of the score in an independent population.

CONCLUSIONS

This score enables the identification of patients at high risk of RD but it cannot provide guidance for the decision to undertake re-excision surgery in the low-risk group. Further studies are needed to test the score in extensive datasets and better identify low-risk patients.