Margin width and local recurrence after breast conserving surgery for ductal carcinoma in situ

Impact of resection margin width on local recurrence following breast-conserving surgery and whole breast radiotherapy for pure ductal carcinoma in situ: a systematic review and meta-analysis

Objective

The aim of this study was to determine the impact of margin width and boost radiotherapy on the local recurrence risk of pure ductal carcinoma in situ (DCIS).

Methods and analysis

This is a prospectively registered systematic review and meta-analysis reporting relative risk (RR), OR and HR margin width outcomes. Eligible studies included prospective and retrospective case series with defining margin widths and 48 months of minimum follow-up. All patients (100%) received adjuvant whole breast radiotherapy (WBRT).

Results

A total of 40 265 patients with pure DCIS in 31 studies were included. ORs and RR were calculated from 15 studies in 12 519 patients, and HRs were calculated from 12 studies in 12 946 patients. Local recurrence was significantly greater with narrower 'close' margins; 0.1-1 mm versus >1 mm in RR (2.88, 95% CI 1.86 to 3.90; p<0.05), OR (4.82, 95% CI 2.45 to 9.48; p<0.05) and HR analysis (1.34, 95% CI 1.01 to 1.67; p<0.05). Compared with margins >2 mm, significantly greater local recurrence was observed in margins 0.1-2 mm in RR (1.72, 95% CI 1.09 to 2.35; p<0.05) and OR (4.43, 95% CI 3.02 to 6.50; p<0.05). Comparing 0.1-1 mm versus >1 mm and 0.1-2 mm versus >2 mm, differences in local recurrence were not statistically significant, once adjusted for boost radiotherapy.

Conclusions

In pure DCIS with WBRT, the local recurrence risk reduces as margin width increases up to 2 mm. The strength of the recommendation for a minimum clear margin of 2 mm is limited by a lack of data comparing 1.1-2 mm with >2 mm. The association between recurrence and close margins is not significant following boost radiotherapy, suggesting a possible alternative to re-excision in patients with close margins <2 mm.

Systematic review registration

CRD42022308524.

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.

Surgical margin and local recurrence of ductal carcinoma in situ

PURPOSE

This study aims to evaluate the association between surgical margin status and local recurrence of DCIS.

METHODS

A retrospective analysis of a prospectively maintained 20-year DCIS database was performed. >=2 mm margin was defined as clear margin. Local relapse rate between the patients with clear versus close margins were analyzed with Kaplan-Meier analyses.

RESULTS

654 patients were analyzed. Median age was 46.5 (Range 18 - 80). 205 (31.3%) were high grade, 194 (29.7%) were intermediate grade, 143 (21.9%) were low grade. 112 (18.3%) were unknown. 202 (30.9%) were estrogen receptor positive, 49 (7.4%) were negative, 403 (61.6%) patients were unknown. 403 (61.6%) patients received mastectomy while 251 (38.4%) patients received BCS and radiotherapy. 549 (83.9%) patients had clear surgical margin, 50 (7.7%) patients had involved (positive) resection margin, 55 (8.4%) had close margin (<2 mm margin). All patients with involved margin received re-excision of margin, while 21 patients (out of 55 who had close resection margins) received re-excision of margin. Negative surgical margins were achieved after the re-excision. 34 patients with close resection margin decided not to receive re-excision but to undergo adjuvant radiotherapy. After median follow-up of 128 months, the 10-year ipsilateral breast tumor relapse (IBTR) was 4.5% (N = 28), Of which 27 (96.4%) patients had clear margin after the initial surgical treatment of DCIS. 1 (3.6%) patient had close surgical margin. Difference in IBTR between the two groups was not statistically significant (p = 0.692).

CONCLUSION

Close surgical margin for DCIS is not associated with increased risk of IBTR.

Optical tissue measurements of invasive carcinoma and ductal carcinoma in situ for surgical guidance

Background

Although the incidence of positive resection margins in breast-conserving surgery has decreased, both incomplete resection and unnecessary large resections still occur. This is especially the case in the surgical treatment of ductal carcinoma in situ (DCIS). Diffuse reflectance spectroscopy (DRS), an optical technology based on light tissue interactions, can potentially characterize tissue during surgery thereby guiding the surgeon intraoperatively. DRS has shown to be able to discriminate pure healthy breast tissue from pure invasive carcinoma (IC) but limited research has been done on (1) the actual optical characteristics of DCIS and (2) the ability of DRS to characterize measurements that are a mixture of tissue types.

Methods

In this study, DRS spectra were acquired from 107 breast specimens from 107 patients with proven IC and/or DCIS (1488 measurement locations). With a generalized estimating equation model, the differences between the DRS spectra of locations with DCIS and IC and only healthy tissue were compared to see if there were significant differences between these spectra. Subsequently, different classification models were developed to be able to predict if the DRS spectrum of a measurement location represented a measurement location with “healthy” or “malignant” tissue. In the development and testing of the models, different definitions for “healthy” and “malignant” were used. This allowed varying the level of homogeneity in the train and test data.

Results

It was found that the optical characteristics of IC and DCIS were similar. Regarding the classification of tissue with a mixture of tissue types, it was found that using mixed measurement locations in the development of the classification models did not tremendously improve the accuracy of the classification of other measurement locations with a mixture of tissue types. The evaluated classification models were able to classify measurement locations with > 5% malignant cells with a Matthews correlation coefficient of 0.41 or 0.40. Some models showed better sensitivity whereas others had better specificity.

Conclusion

The results suggest that DRS has the potential to detect malignant tissue, including DCIS, in healthy breast tissue and could thus be helpful for surgical guidance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01436-5.

Management and 5-year outcomes in 9938 women with screen-detected ductal carcinoma in situ: the UK Sloane Project

BACKGROUND

Management of screen-detected ductal carcinoma in situ (DCIS) remains controversial.

METHODS

A prospective cohort of patients with DCIS diagnosed through the UK National Health Service Breast Screening Programme (1st April 2003 to 31st March 2012) was linked to national databases and case note review to analyse patterns of care, recurrence and mortality.

RESULTS

Screen-detected DCIS in 9938 women, with mean age of 60 years (range 46-87), was treated by mastectomy (2931) or breast conserving surgery (BCS) (7007; 70%). At 64 months median follow-up, 697 (6.8%) had further DCIS or invasive breast cancer after BCS (7.8%) or mastectomy (4.5%) (p < 0.001). Breast radiotherapy (RT) after BCS (4363/7007; 62.3%) was associated with a 3.1% absolute reduction in ipsilateral recurrent DCIS or invasive breast cancer (no RT: 7.2% versus RT: 4.1% [p < 0.001]) and a 1.9% absolute reduction for ipsilateral invasive breast recurrence (no RT: 3.8% versus RT: 1.9% [p < 0.001]), independent of the excision margin width or size of DCIS. Women without RT after BCS had more ipsilateral breast recurrences (p < 0.001) when the radial excision margin was <2 mm. Adjuvant endocrine therapy (1208/9938; 12%) was associated with a reduction in any ipsilateral recurrence, whether RT was received (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.41-0.80) or not (HR 0.68; 95% CI 0.51-0.91) after BCS. Women who developed invasive breast recurrence had a worse survival than those with recurrent DCIS (p < 0.001). Among 321 (3.2%) who died, only 46 deaths were attributed to invasive breast cancer.

CONCLUSION

Recurrent DCIS or invasive cancer is uncommon after screen-detected DCIS. Both RT and endocrine therapy were associated with a reduction in further events but not with breast cancer mortality within 5 years of diagnosis. Further research to identify biomarkers of recurrence risk, particularly as invasive disease, is indicated.