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.

Treatments and Prognosis of the Breast Ductal Carcinoma In Situ

INTRODUCTION

With progress in treatments, breast ductal carcinoma in situ (DCIS) outcomes have substantially improved. However, as various treatment methods are used in different countries and institutions, consensus on the optimal treatment method is lacking. This study aimed to analyze the prognostic factors and provide a reference for optimizing the clinical treatment of DCIS.

PATIENTS AND METHODS

This retrospective clinical study collected data from DCIS patients at the Sun Yat-sen University Cancer Center from 2010 to 2017. The Kaplan-Meier method and Cox regression model were used to assess disease-free survival (DFS), overall survival (OS), and local control (LC) rates.

RESULTS

Among the 483 included patients, 83.6% (404) underwent mastectomies. The median follow-up time was 101 months. The number of patients undergoing breast-conserving surgery (BCS) with radiotherapy has gradually increased. Axillary lymph node dissection was the main surgery performed from 2010 to 2015, and the proportion of sentinel lymph node biopsies (SLNBs) has increased. LC and DFS rates with BCS without radiotherapy were significantly lower than those with mastectomy (P = .002; P < .001). Additionally, the patients who did not undergo axillary surgery had worse LC and OS rates than those who underwent SLNB (P = .028 and P = .038). Endocrine therapy (ET) or its duration had no significant effect on prognosis.

CONCLUSION

In conclusion, BCS without radiotherapy and lack of axillary surgery were independent prognostic factors. We recommend performing BCS with radiotherapy and SLNB more in clinical practice, as well as shortening the ET duration.

Tailored radiation dose according to margin width for patients with ductal carcinoma in situ after breast-conserving surgery

A 2 mm resection margin is considered adequate for ductal carcinoma in situ (DCIS). We assessed the effectiveness of a tailored radiation dose for margins < 2 mm and the appropriate margin width for high-risk DCIS. We retrospectively evaluated 137 patients who received adjuvant radiotherapy after breast-conserving surgery for DCIS between 2013 and 2019. The patients were divided into three- positive, close (< 2 mm), and negative (≥ 2 mm) margin groups. Radiation dose to the tumor bed in equivalent dose in 2 Gy fractions were a median of 66.25 Gy, 61.81 Gy, and 59.75 Gy for positive, close, and negative margin groups, respectively. During a median follow-up of 58 months, the crude rates of local recurrence were 15.0%, 6.7%, and 4.6% in the positive, close, and negative margin groups, respectively. The positive margin group had a significantly lower 5-year local recurrence-free survival (LRFS) rate compared to the close and negative margin groups in propensity-weighted log-rank analysis (84.82%, 93.27%, and 93.20%, respectively; p = 0.008). The difference in 5-year LRFS between patients with the high- and non-high-grade tumors decreased as the margin width increased (80.4% vs. 100.0% for margin ≥ 2 mm, p < 0.001; 92.3% vs. 100.0% for margin ≥ 6 mm, p = 0.123). With the radiation dose tailored for margin widths, positive margins were associated with poorer local control than negative margins, whereas close margins were not. Widely clear margins (≥ 2 mm) were related to favorable local control for high-grade DCIS.

The Feasibility of Omitting Postoperative Radiotherapy in Japanese Patients With Ductal Carcinoma In Situ of Breast Treated With Breast-Conserving Surgery

Background To analyze the feasibility of omitting postoperative radiotherapy (PORT) after breast-conserving surgery (BCS) in Japanese patients with ductal carcinoma in situ (DCIS). Materials and methods We retrospectively analyzed 88 patients with small pure DCIS (median diameter 1.1 cm, ≤ 4 cm) who underwent BCS with (n = 39) or without (n = 49) PORT. The primary and secondary endpoints were ipsilateral breast tumor recurrence (IBTR) and overall survival (OS), respectively, between the groups that received PORT and those that did not. Results The PORT group included a high number of margin-positive cases. The incidence of IBTR was 2.4% (95% confidence interval (CI), 0.3-15.7%) and 2.8% (95% CI, 0.4-18.2%) at five years and 5.5% (95% CI, 1.4-20.6%) and 2.8% (95% CI, 0.4-18.2%) at 10 years in patients without and with PORT, respectively (p = 0.686). In the margin-negative group, only one patient showed IBTR without RT (2.3%), whereas no patient with PORT experienced IBTR (0%). To date, there have been no regional or distant metastases; therefore, no patient has experienced breast cancer-related deaths. The OS rates were 97.7% (95% CI, 84.9-99.6%) and 100% at 10 years in patients without and with PORT, respectively (p = 0.372). Conclusion This study suggests that the omission of PORT after BCS could be a feasible option for selected Japanese patients but requires further investigation to identify the low-risk factor in patients who can omit PORT.

Ductal Carcinoma in Situ: A Detailed Review of Current Practices

Ductal carcinoma in situ is a challenge for breast surgeons, beginning with its difficult radiological detection and continuing with its contentious multimodal treatment and management. It is becoming more common as a result of widespread screening mammography and usually manifests as a cluster of calcifications. Patients are usually asymptomatic or present with a small, palpable lump. It is, however, a premalignant lesion that has the potential to progress to invasive carcinoma and is treated similarly with multimodal therapy. Treatment options currently include total or simple mastectomy with sentinel lymph node biopsy or lumpectomy with radiation. Tamoxifen and human epidermal growth factor receptor two suppression therapy are examples of adjuvant therapy. A review of consensus guidelines and literature was performed, in which we included the available online literature on the concerned topic from 2000-2022. This article is not a complete review of all the available literature; rather, it is a comprehensive review of the topic and its current management guidelines.

Reoperation rate of ductal carcinoma in situ: impact of tomosynthesis (3D) and spot magnification

BACKGROUND

Surgical planning depends on precise preoperative assessment of the radiological extent of ductal carcinoma in situ (DCIS). Despite different modalities used, reoperation rates for DCIS due to involved margins are high.

PURPOSE

To evaluate the impact of additional imaging views (spot magnification, tomosynthesis) on surgical reoperation rate of DCIS.

MATERIAL AND METHODS

The retrospective single institute study includes 157 patients with biopsy-proven pure DCIS seen on mammogram as microcalcifications and treated with breast-conserving surgery. Patients have been divided into three groups according to additional imaging performed: spot magnification, tomosynthesis, and none. All breast images (mammograms, spot magnification, tomosynthesis) were reviewed and the maximum extent of pathological microcalcifications was recorded. Radiological size was compared to final histopathological size. Reoperation rate due to inadequate margins was recorded.

RESULTS

Reoperation rates (25%) due to inadequate margins were as follows: spot (18%), tomosynthesis (27%), none (31%); P = 0.488. Spot magnification, tomosynthesis, and digital zoom of full-field digital mammography predicted similarly the final histopathological size. Reoperation group had a significantly greater preoperative radiological median size (26 mm vs. 20 mm; P = 0.014) as well as median size of disease on final histopathological report (29 mm vs. 14 mm; P < 0.001). Discrepancy between radiological and final histopathological size became greater with increasing DCIS extent.

CONCLUSION

The main factors for reoperations are DCIS size and discordance between radiological and histopathological sizes. The use of additional imaging views (spot magnification, tomosynthesis) did not reduce reoperation rate.

Breast Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. These NCCN Clinical Practice Guidelines for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of ductal carcinoma in situ and the workup and locoregional management of early stage invasive breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.

Significance of boost radiotherapy in early invasive ductal breast cancer with ductal carcinoma in situ component under negative surgical margins

We hypothesize that there is a risk of ipsilateral breast tumor recurrence (IBTR) in surgical margin-free invasive ductal carcinoma (IDC) in the presence of ductal carcinoma in situ (DCIS) component affecting surgical margins in early stage. From 1990 to 2014, 343 patients with IDC in which the DCIS component constitute have received radiotherapy (RT) following breast-conserving surgery (BCS). All patients received whole breast irradiation with a prescribed dose of 50 Gy in 20 fractions (four times a week). This one-arm cohort with boost RT (253 patients) was compared for IBTR with a non-cohort group receiving no boost RT because of freedom from positive margins (90 patients). Median observation months were 98 (boost group) vs 119 (no boost group), respectively. The 15-year local recurrence-free survival (LRFS) rates were 98.5% and 85.6% in the boost and no boost groups, respectively (Cox proportional hazards model univariate analysis; p = 0.013, HR 0.13). Similarly, for other background factors, there was a significant difference in the LRFS between age groups. The 15-year LRFS rate was 91.8% in patients aged 45 years or younger and 94.6% in patients older than 46 years (p = 0.031, HR 0.21), respectively. Only these two factors were independently significant in Cox proportional hazards model multivariate analysis. IBTR risk in margin-free IDC with DCIS component was independently decreased by boost RT in the cohort setting. Tumor size, extensive intraductal component (EIC), boost dose, the presence of lymph node (LN) metastasis and hormonal therapy were not IBTR risk factors in this study.

Tumor margins that lead to reoperation in breast cancer: A retrospective register study of 4,489 patients

Background and Objectives

Optimal margins for ductal carcinoma in situ (DCIS) remain controversial in breast‐conserving surgery (BCS) and mastectomy. We examine the association of positive margins, reoperations, DCIS and age.

Methods

A retrospective study of histopathological reports (4489 patients). Margin positivity was defined as ink on tumor for invasive carcinoma. For DCIS, we applied 2 mm anterior and side margin thresholds, and ink on tumor in the posterior margin.

Results

The incidence of positive side margins was 20% in BCS and 5% in mastectomies (p < 0.001). Of these patients, 68% and 14% underwent a reoperation (p < 0.001). After a positive side margin in BCS, the reoperation rates according to age groups were 74% (<49), 69% (50–64), 68% (65–79), and 42% (80+) (p = 0.013). Of BCS patients with invasive carcinoma in the side margin, 73% were reoperated on. A reoperation was performed in 70% of patients with a close (≤1 mm) DCIS side margin, compared to 43% with a wider (1.1–2 mm) margin (p = 0.002). The reoperation rates were 55% in invasive carcinoma with close DCIS, 66% in close extensive intraductal component (EIC), and 83% in close pure DCIS (p < 0.001).

Conclusions

Individual assessment as opposed to rigid adherence to guidelines was used in the decision on reoperation.

Retrospective, Multicenter Analysis Comparing Conventional with Oncoplastic Breast Conserving Surgery: Oncological and Surgical Outcomes in Women with High-Risk Breast Cancer from the OPBC-01/iTOP2 Study

Introduction

Recent data suggest that margins ≥2 mm after breast-conserving surgery may improve local control in invasive breast cancer (BC). By allowing large resection volumes, oncoplastic breast-conserving surgery (OBCII; Clough level II/Tübingen 5-6) may achieve better local control than conventional breast conserving surgery (BCS; Tübingen 1-2) or oncoplastic breast conservation with low resection volumes (OBCI; Clough level I/Tübingen 3-4).

Methods

Data from consecutive high-risk BC patients treated in 15 centers from the Oncoplastic Breast Consortium (OPBC) network, between January 2010 and December 2013, were retrospectively reviewed.

Results

A total of 3,177 women were included, 30% of whom were treated with OBC (OBCI n = 663; OBCII n = 297). The BCS/OBCI group had significantly smaller tumors and smaller resection margins compared with OBCII (pT1: 50% vs. 37%, p = 0.002; proportion with margin <1 mm: 17% vs. 6%, p < 0.001). There were significantly more re-excisions due to R1 (“ink on tumor”) in the BCS/OBCI compared with the OBCII group (11% vs. 7%, p = 0.049). Univariate and multivariable regression analysis adjusted for tumor biology, tumor size, radiotherapy, and systemic treatment demonstrated no differences in local, regional, or distant recurrence-free or overall survival between the two groups.

Conclusions

Large resection volumes in oncoplastic surgery increases the distance from cancer cells to the margin of the specimen and reduces reexcision rates significantly. With OBCII larger tumors are resected with similar local, regional and distant recurrence-free as well as overall survival rates as BCS/OBCI.

Supplementary information

The online version contains supplementary material available at 10.1245/s10434-021-10809-1.

Does margin width impact breast cancer recurrence rates in women with breast conserving surgery for ductal carcinoma in situ?

PURPOSE

Controversy remains regarding the optimal margin width for patients with ductal carcinoma in situ (DCIS) who undergo breast conserving surgery (BCS).

METHODS

Women with a primary DCIS diagnosis were enrolled in a statewide population-based cohort from 1997 to 2006. Patients were surveyed every two years with follow-up data available through 2016. Surgical pathology reports were collected for 559 participants following breast conserving surgery. Multivariable Cox proportional hazard models evaluated relationships between locoregional recurrence (LRR) and margin width in the presence or absence of adjuvant radiation therapy while controlling for age, menopausal status and duration of endocrine therapy use.

RESULTS

The majority of women in this study were over 50yo (74%), 34% had high grade disease, and 77% underwent radiation. The overall LRR rate was 12%. A LRR occurred in 46 women who had radiation (11%) and 23 women who did not undergo radiation (19%). Univariate analysis identified smaller margin width, younger age, premenopausal status, no radiotherapy, and shorter endocrine therapy use associated with LRR. Multivariable models demonstrated that close margins (< 2 mm) were associated with an increased risk of recurrence when compared to margins ≥ 2 mm in width whether women received radiation (HR 1.98 CI 0.87-4.54) or not (HR 1.32 CI 0.27-6.49), but confidence intervals were wide.

CONCLUSIONS

In this study, patients with DCIS and close margins were less likely to experience recurrence after routine re-excision to margins greater than 2 mm.

Role of early post-operative breast MRI: how helpful is it in deciding the next step for women who may have residual disease?

Objectives

Positive resection margins following breast conserving surgery are a risk factor for local disease recurrence. Subsequent management of patients is often not straightforward, with post-operative breast MRI increasingly used to aid decision-making. Interpretation of MRI after surgery can prove challenging due to local inflammatory enhancement. We reviewed our experience of post-operative breast MRIs to determine their ability to detect residual disease and to evaluate how they changed initial patient management from re-excision to an alternative.

Methods:

A search of breast MRIs performed from August 2014 to December 2019 was undertaken, to identify those performed post-operatively within 4 months of breast conserving surgery. Electronic patient records and imaging were evaluated to determine additional work-up, pathology and surgical outcomes.

Results:

Of the 2274 breast MRIs during the study period, 44 (2%) were performed post-operatively to evaluate 47 breasts. MRI was normal in 20 cases (43%), suspicious findings at surgical cavity only in 13 (28%), suspicious ipsilateral distant breast findings only in 6 (13%), and both cavity and distant findings in 7 cases (15%). Contralateral abnormalities were identified in 3 cases. Following MRI, mastectomy was performed in 11 cases, re-excision in 25, with 2 subsequent mastectomies, and multidisciplinary team accepted margins in 11 cases, 10 of whom underwent post-operative radiotherapy. MRI altered initial patient management from re-excision to an alternative in 25 cases (45%).

Conclusion:

Post-operative breast MRI, although potentially challenging to interpret, can prove useful in planning the next step in patient management, particularly in its ability to evaluate the whole breast.

Advances in knowledge

Post-operative breast MRI is increasingly requested at multidisciplinary team following breast conserving surgery with positive surgical margins on histology, however interpretation is challenging. The value of these studies lie in assessment of the distant breast rather than the surgical resection cavity and can alter patient management guiding the most appropriate next step for definitive treatment.

Impact of consensus guidelines for breast-conserving surgery in patients with ductal carcinoma in situ

Background

Consensus guidelines published in 2016 recommended a 2 mm free margin as the standard for negative margins in patients undergoing breast‐conserving surgery (BCS) for ductal carcinoma in situ (DCIS). The goal of the guideline recommendation was standardization of re‐excision practices.

Aims

To evaluate the impact of this consensus guideline on our institutional practices.

Methods

We identified all patients at our institution with pure DCIS who were initially treated with BCS from September 2014 to August 2018 using a prospectively‐maintained institutional database. A retrospective chart review was performed to determine margin status and re‐excision rates during the 2 years before and the 2 years after the guideline was published in order to determine the effect on our re‐excision rates. Close margins were defined as <2 mm.

Results

In the 2 years before the consensus guideline was published, 184 patients with DCIS underwent BCS. Twenty‐six patients had positive margins and 24 underwent re‐excision, including three who had completion mastectomy. Of the remaining 159 patients, 76 had ≥2 mm (negative) margins. The remaining 82 patients had close margins and 48 of these patients (58.5%) underwent re‐excision, including one who had a completion mastectomy. Excluding the patients with positive margins, our re‐excision rate was 30.4% prior to the guideline. In the 2 years after the consensus guideline was published, 192 patients with DCIS underwent initial BCS. Twenty‐four patients had positive margins and 22 underwent re‐excision, including three who had completion mastectomy. Of the remaining 168 patients, 95 patients had ≥2 mm (negative) margins. The remaining 73 patients had close margins and 45 of those patients (61.6%) underwent re‐excision, including six who had completion mastectomy. Excluding the patients with positive margins, our re‐excision rate was 26.8% after the guideline.

Conclusions

Our institution's re‐excision rate did not change significantly during the 2 years before and after the publication of the consensus guideline on adequate margins for patients undergoing BCT for DCIS. Our overall re‐excision rate decreased slightly. However, of the patients who had close margins, a larger proportion underwent re‐excision after the guideline was published. The guideline publication appears to have affected our institutional practices slightly, but not dramatically as many of our surgeons' practices were comparable to the guideline recommendations prior to 2016. We continue to use clinical judgment based on patient and tumor characteristics in deciding which patients will benefit from margin re‐excision.

Ultrasound-Guided Laser Ablation After Excisional Vacuum-Assisted Breast Biopsy for Small Malignant Breast Lesions: Preliminary Results

Background:

The purpose of this preliminary study is to evaluate the feasibility of the excisional ultrasound (US) guided vacuum-assisted breast biopsy (VAE), followed by US-guided Laser Interstitial Thermal Therapy (LITT) in the treatment of unifocal ductal breast carcinomas ≤ 1 cm and estimate the ablation rate analyzing the final histopathological results after subsequent surgical excision.

Methods:

In a single session 11 female patients with unifocal less than a centimeter breast cancer underwent 2 different minimally invasive percutaneous US-guided techniques: a VAE breast biopsy with an 8 G needle to remove the lesion and, immediately after, a LITT ablation in the biopsy site. Four weeks later, all patients underwent radiological follow-up. Afterward, a systematic surgery was performed, the ablation rate was calculated, and iconographic and histological features were correlated.

Results:

Average maximum diameter of the lesions was 7.6 mm (5-10 mm). No patient reported pain or discomfort during procedure. 1/11 patient (9.1%) reported an early minor complication (a small superficial skin burn). After surgical excision, the histopathological evaluation reported in 10/11 cases (90.9%) complete ablation of the target lesion. In only one case (9.1%) residual cancer was detected. The necrotic-hemorrhagic cavities showed a mean maximum diameter of 27.3 mm (20-35 mm).

Conclusions:

Laser ablation performed after excisional biopsy could be considered a valid alternative to surgical excision for the treatment of lesions ≤ 1 cm, if carried out by expert radiologists. The association of these minimally invasive percutaneous methods has proven to be reliable, fast, and safe with an ablation rate of 90.9% and excellent aesthetic results. RM and CESM are potentially able to quantifying treatment results and to follow-up the ablation effects.

[Diagnosis of breast diseases in a certified breast center]

The beginning of the 21st century has seen immense improvements in the quality of diagnosis and treatment of breast cancer due to several, simultaneous developments. In particular, the introduction of a certification program from the German Cancer Society based on level III guidelines has enhanced the transparency and quality of treatment of breast diseases for all actors. As a result, patients have benefited from intensified cooperation especially between core disciplines in breast disease, gynecology, pathology, and radiology. The standardized and synoptic reading of multiple diagnostic modalities has enabled precise sampling of histologic specimen, which has improved prognosis and the successful individualization of therapy. In this article the benefits of breast cancer diagnosis and therapy in a certified breast center are illustrated using four case examples.

[Overall survival and survival without local recurrence in case of radiotherapy of the tumor bed of ductal carcinomas in situ of the breast: Review of the literature]

INTRODUCTION

Carcinomas in situ represent more than 15 to 20% of breast cancers. Radiotherapy of whole breast is part of the therapeutic standard and follows surgery. However, the indication of tumor bed irradiation is still controversial and heterogeneous according to international practice even though it is a very frequent clinical situation. The aim of this study is to define the indications of tumor bed irradiation in the context of ductal carcinomas in situ and to discuss accelerated partial irradiation of the breast.

METHOD

The selected papers were published between 2015 and 2020 and included as MeSH terms "ductal carcinoma in situ" and "boost" for the analysis of tumor bed irradiation, and "ductal carcinoma in situ" and "accelerated partial breast irradiation" for the analysis of accelerated partial irradiation.

RESULTS

Boost was more often performed when risk factors for local recurrence were present, such as age less than 40 or 50 years old, clinical mode of detection, tumor size greater than 15 to 20mm, high nuclear grade, presence of necrosis, positive or insufficient surgical margins, associated atypical hyperplastic lesions, and lobular carcinoma in situ. Accelerated partial irradiation is an option for favorable or intermediate prognosis CCIS, further studies involving more patients are required.

CONCLUSION

Radiotherapy of the mammary gland in the context of DCIS has shown its effectiveness in terms of local and locoregional control of the disease, thus reducing in situ and infiltrating recurrences. However, the indication of operating bed irradiation is still debated, and the practice is very heterogeneous depending on the country. Another possible alternative for patients with a favorable prognosis and a small tumor bed volume would be IPA.

Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional Nipple-Sparing Mastectomy for Breast Cancer Based on Initial Experience

Purpose

Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM).

Methods

Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device. We also analyzed demographic information, pathology, operative time, and complications.

Results

No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications.

Conclusion

The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

Minimally invasive tumor bed implant (MITBI) and peri-operative high-dose-rate brachytherapy (PHDRBT) for accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost) in breast-conserving surgery for ductal carcinoma in situ

Purpose

To evaluate our institutional experience of minimally invasive tumor bed implantation (MITBI) during breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) to deliver peri-operative high-dose-rate brachytherapy (PHDRBT) as accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost).

Material and methods

Patients older than 40, with clinical and radiological unifocal DCIS < 3 cm were considered potential candidates for accelerated partial breast irradiation (APBI) and were implanted during BCS using MITBI-technique. Patients who in final pathology reports showed free margins and no other microscopic tumor foci, received AMBI with PHDRBT (3.4 Gy BID in 5 days). Patients with adverse features received A-PHDRBT-boost with post-operative external beam radiotherapy (EBRT).

Results

Forty-one patients were implanted, and 36 were treated and analyzed. According to final pathology, 24 (67%) patients were suitable for AMBI and 12 (33%) were qualified for A-PHDRBT-boost. Reoperation rate for those with clear margins was 16.6% (6/36); this rate increased to 33% (4/12) for G3 histology, and 66% (4/6) were rescued using AMBI. Early complications were documented in 5 patients (14%). With a median follow-up of 97 (range, 42-138) months, 5-year rates of local, elsewhere, locoregional, and distant control were all 97.2%. 5-year ipsilateral breast tumor recurrence rates (IBTR) were 5.6% (2/36), 8.3% (2/24) for AMBI, and 0% (0/12) for A-PHDRBT-boost patients. Both instances of IBTR were confirmed G3 tumors in pre-operative biopsies; no IBTR was documented in G1-2 tumors. Cosmetic outcomes were excellent/good in 96% of AMBI vs. 67% in A-PHDRBT-boost (p = 0.034).

Conclusions

The MITBI-PHDRBT program allows selection of patients with excellent prognoses (G1-2 DCIS with negative margins and no multifocality), for whom AMBI could be a good alternative with low recurrence rate, decrease of unnecessary radiation, treatment logistics improvement, and over-treatment reduction. Patients whose pre-operative biopsy showed G3 tumor, presents with inferior local control and more risk of reoperation due to positive margins.

A Single institution's randomized double-armed prospective study of lumpectomy margins with adjunctive use of the MarginProbe in nonpalpable breast cancers

Breast conservation surgery (BCS) aims to excise all cancerous tissue while minimizing the amount of healthy breast tissue removed. Up to 30% of patients undergoing BCS require a second operation for re-excision to obtain negative margins. Previous studies reported a lower re-excision rate with intraoperative use of the MarginProbe device (Dune Medical Devices). This device utilizes radiofrequency spectroscopy to detect differences between cancerous and normal tissue. From July 2009 to January 2010, our institution enrolled 46 patients electing for BCS in a prospective double-arm randomized controlled trial and had a significantly lower re-excision rate than that reported in the multicenter trial. Intraoperatively, after performing conventional lumpectomy with excision of any additional shavings deemed necessary based on palpation and visual inspection alone, patients were then randomized. In the device arm, the surgeon used the MarginProbe to interrogate the lumpectomy specimen, taking additional shavings from the cavity surfaces corresponding to the parts of the specimen read as positive by the device. In the control arm, only standard intraoperative assessments were performed. All specimens were evaluated by pathologists who were blinded to the study arm. In this population, 72% had invasive ductal carcinoma (IDC), 20% had ductal carcinoma in situ (DCIS), and 8% had invasive lobular carcinoma (ILC). Average age was 64 years old. The average size of the specimen was 5.6 cm, the average volume was 37.8 cm³ , and the average weight was 32.7 g. The mean size of DCIS was 1.4 cm. For invasive specimens, 32 were T1 and 7 were T2. Prior to randomization, 43 patients were thought to have positive or close margins and therefore underwent additional shavings. Twenty-three patients were randomized to the device arm and 23 to the control arm. In the device arm, 14 (60%) patients had IDC, 7 (30%) had DCIS, and 2 (8%) had ILC, vs the control arm where 19 (82%) patients had IDC, 2 (8%) had DCIS, and 2 (8%) had ILC. Eight (35%) patients in the control group vs 1 (4%) in the device group underwent re-excision for margin involvement (P < .05). The use of the MarginProbe device at our institution significantly improved the ability of our surgeons to obtain clear margins during initial BCS. Our results show a lower re-excision rate (4%) than those published in the multicenter trial (19.8%). We postulate that in the face of more patients having DCIS in our device group (30%), our surgeons responded by taking thicker shavings when the MarginProbe device reported margin involvement during the initial lumpectomy, resulting in greater success achieving clear final margins on the shaved tissue and a significantly lower re-excision rate than previously reported with the MarginProbe device.

Differences in Re-excision Rates for Breast-Conserving Surgery Using Intraoperative 2D Versus 3D Tomosynthesis Specimen Radiograph

BACKGROUND

Intraoperative specimen radiographs performed during breast conservation surgery for cancer reduces the need for re-excision for positive margins. We studied 2D versus 3D image-guided cavity margin excision and compared it to final pathology and need for additional surgery.

METHODS

We conducted a retrospective review of 657 breast-conserving operations performed for cancer from 2013 to 2018. Procedures were performed by four surgeons at a single tertiary institution with access intraoperatively to 2D and 3D radiographs. Data collected included demographics, intraoperative margin assessment, final pathology, and re-excision rates.

RESULTS

A total of 466 patients had 2D and 191 had 3D specimen imaging. The 2D group had a lower mean age and a higher body mass index and proportion of minority patients than the 3D group (P < 0.01). In the 3D group, there was a higher percentage of patients with mammographically denser breasts (P < 0.06); 58% of patients in the 3D group had additional imaging-directed cavity margins excised versus 32% of patients in the 2D group (P < 0.01). In the 2D group, 44 patients (9%) had positive final margins versus 8 patients (4%) in the 3D group (P = 0.02). No difference was found on total volume of excision (P = 0.56). The re-excision rate for the 2D group was 11% versus 5% for the 3D group (P = 0.02; adjusted odds ratio = 0.41, 95% confidence interval 0.19-0.86).

CONCLUSIONS

Re-excision rates using both modalities are low. A lower re-excision rate is independently associated with 3D tomosynthesis. This allows surgeons to excise additional margins at the index operation, decreasing reoperations and anxiety/costs for patients.

Preoperative breast cancer staging with multi-modality imaging and surgical outcomes

PURPOSE

To compare the rates of mastectomy and re-operation after breast-conserving surgery (BCS) among patients who had different pre-operative multi-modality imaging, hence identifying significant predictors of mastectomy and re-operations within each group.

METHOD

Retrospective study of consecutive patients with primary breast cancer treated January 2010 - December 2016, divided in 3 groups, undergoing pre-operative local staging respectively with conventional imaging modalities only (2D mammography, ultrasound (US)), conventional imaging and tomosynthesis (DBT) and/or MRI. The primary outcome was identification of significant predictors of surgical outcomes, within each group. Study variables examined in univariate analysis were age, lesion dimension, breast density, multifocality, tumor size, histology, and if associated with outcomes they were included in binary logistic regression analysis.

RESULTS

Amongst 1547 patients, patient and tumor characteristics differed across the three groups, as did mastectomy rates which were 18 % (102/562) for 2D + US, 36 % (154/428) for 2D + DBT + US, 45 % (250/557) for 2D+/-DBT + US + MRI(p < 0.001). Variables strongly associated with mastectomy were larger lesions and multifocality (as was multi-modality group). Re-operation rate showed an opposite trend: 12.2 % (56/459) for 2D + US, 8 % (22/272) for 2D + DBT + US, 6.5 % (20/306) for 2D+/-DBT + US + MRI. Re-operation rate for 2D+/-DBT + US + MRI was lower than for 2D + US (p = 0.01) but similar to 2D + DBT + US (p = 0.58). Patients who had 2D + US and re-operations had significantly larger lesions, more underestimation, higher proportion of invasive carcinoma with in-situ component than those who did not require re-operation.

CONCLUSIONS

Patients who had larger tumors and multifocal disease were more frequently staged by adding DBT and/or MRI to conventional imaging (mammography and US) which was associated with more extensive surgical treatment but lower reoperation rates.

[Ductal carcinoma in situ in 2019: Diagnosis, treatment, prognosis]

Ductal carcinoma in situ (DCIS) currently represents up to 15% of the newly diagnosed breast cancers, and are almost always detected by microcalcifications. Global prognosis is good (3% of 15-year specific mortality) but invasive local recurrences (LR) can lead to metastasis in 12-15% of the cases. Breast conserving surgery with whole breast irradiation is the main treatment (reducing LR by 50%), but mastectomy (with or without reconstruction) is performed in about 30% of the cases due to wide lesion size and/or multicentricity. The role of tamoxifen remains unclear. Axillary dissection is needless but sentinel node biopsy is proposed in case of micro-invasion suspicion (large lesions with high grade). The main factors of LR are young age (≤40 years) incomplete excision, and high nuclear grade with comedonecrosis. Several studies on "therapeutic descalation" are still ongoing in order to identify the "low risk" DCIS (about 10% of the cases) in which radiotherapy could be safely omitted.

Ductal Carcinoma In Situ and Margins <2 mm: Contemporary Outcomes With Breast Conservation

OBJECTIVE

To determine the relationship between negative margin width and locoregional recurrence (LRR) in a contemporary cohort of ductal carcinoma in situ (DCIS) patients.

BACKGROUND

Recent national consensus guidelines recommend an optimal margin width of 2 mm or greater for the management of DCIS; however, controversy regarding re-excision remains when managing negative margins <2 mm.

METHODS

One thousand four hundred ninety-one patients with DCIS who underwent breast-conserving surgery from 1996 to 2010 were identified from a prospectively managed cancer center database and analyzed using univariate and multivariate Cox proportional hazard models to determine the relationship between negative margin width and LRR with or without adjuvant radiation therapy (RT).

RESULTS

A univariate analysis revealed that age <40 years (n = 89; P = 0.02), no RT (n = 298; P = 0.01), and negative margin width <2 mm (n = 120; P = 0.005) were associated with LRR. The association between margin width and LRR differed by adjuvant RT status (interaction P = 0.02). There was no statistical significant difference in LRR between patients with <2 mm and ≥2 mm negative margins who underwent RT (10-yr LRR rate, 4.8% vs 3.3%, respectively; hazard ratio, 0.8; 95% CI, 0.2-3.2; P = 0.72). For patients who did not undergo RT, those with margins <2 mm were significantly more likely to develop a LRR than were those with margins ≥2 mm (10-yr LRR rate, 30.9% vs 5.4%, respectively; hazard ratio, 5.5; 95% CI, 1.8-16.8, P = 0.003).

CONCLUSIONS

Routine additional surgery may not be justified for patients with negative margins <2 mm who undergo RT but should be performed in patients who forego RT.

Dosimetric evaluation of the INTRABEAM system for breast intraoperative radiotherapy: A single-institution experience

Breast intraoperative radiotherapy (IORT) with the INTRABEAM system uses a 50 kV x-ray source to deliver a single fraction of radiation therapy to the lumpectomy cavity during breast-conserving surgery. We seek to perform a dosimetric analysis of the lumpectomy cavity for rigid spherical applicators. Water phantom measurements were acquired to validate the vendor-provided x-ray calibration. The planning target volume (PTV) was defined as a 10 mm expansion beyond the spherical applicator, a dose-volume histogram (DVH) was generated and dose-volume parameters [D_min, D_1mm, V₉₀, V₈₀, V₅₀, HI] were reported. Additionally, the therapeutic treatment depth using the 90 and 80% isodose level was computed [R₉₀, R₈₀]. When the percent depth dose (PDD) is normalized to the surface of the applicator, smaller applicators have a steeper PDD. For a prescription dose of 20 Gy to the surface of the applicator, the range of dose-volume parameters for the PTV was: 3.15 to 6.84 Gy for D_min, 16.2 to 17.6 Gy for D_1mm, 2.6 to 6.9% for V₉₀, 5.5 to 15.1% for V₈₀, and 21.1 to 55.6% for V₅₀. For applicators 15 to 50 mm in diameter, the reported values were: 6.35 to 2.9 for HI, 0.53 to 0.85 mm for R₉₀, and 1.18 to 1.85 mm for R₈₀. Smaller applicators have reduced PTV coverage but elevated HI because the attenuation of the beam proximal to the source is more pronounced. Additionally, the presence of the aluminum filter for small applicators (≤30 mm) increases PTV coverage but reduces the dose rate on the applicator surface. The delivery of IORT is performed in the OR without the use of image-based planning. To overcome this limitation, we have generated sample DVH's and report dosimetric parameters to offer clinicians a unique dosimetric perspective.

Evidence map of ductal carcinoma in situ management options

OBJECTIVE

Ductal carcinoma in situ (DCIS) has the potential to progress to invasive carcinoma. The optimal management of DCIS and methods for individualizing treatment of DCIS are still being determined. This evidence map depicts the robustness and topical span of research on DCIS management choice on patient-centered and clinical outcomes.

METHODS

We searched PubMed, EMBASE, PsycINFO, PubMed Health, PROSPERO, and clinical practice guideline sites to identify systematic reviews of DCIS management options and consulted with topic experts. A bubble plot visualizes the literature volume and research content for patient-centered outcomes. An online decision tree facilitates discussions with patients and guides through the available evidence.

RESULTS

In total, 40 systematic reviews met inclusion criteria. The research syntheses addressed DCIS management options, including the role of magnetic resonance imaging, axillary surgery/sentinel lymph node biopsy, and excisional biopsy. The map shows existing evidence for mutually exclusive treatment options including active surveillance, breast-conserving surgery, nipple sparing mastectomy, and simple mastectomy. Research findings for intraoperative radiation, adjuvant radiation therapy, adjuvant hormone therapy, hypofractionation radiotherapy, accelerated partial breast irradiation, radiation therapy plus boost, and combined radiation and hormone therapy, as well as for breast reconstruction after mastectomy and surveillance mammography postsurgery are also displayed. The evidence map highlights a scarcity of robust evidence on patient-centered outcomes.

CONCLUSIONS

The evidence map provides an overview of DCIS research showing the range of management options and remaining decisional dilemmas that follow a diagnosis of DCIS. It maps the evidence in accessible tools to guide practice and future research. : Video Summary:http://links.lww.com/MENO/A448.

[For which patients could we consider de-escalation in the management of ductal carcinomas in situ?]

Ductal carcinomas in situ (DCIS) of the breast account for 85% to 90% of breast cancer in situ. Current recommendations for the management of DCIS in France are based on surgical excision of the lesions, lumpectomy in healthy margins (margins of excision≥2mm) or mastectomy in case of extensive lesions. Radiation therapy is recommended after conservative surgical treatment. However, it seems relevant for some patients to discuss the benefit of a therapeutic de-escalation. Indeed, it has been reported that radiotherapy has no major impact on overall survival and that its interest could be discussed in the low-risk situations of invasive recurrence for which surgery alone could be sufficient, subject to sufficient margins. These questions call for the precise definition of low risk populations and to clarify the importance of taking into account decision support tools and new molecular markers. The place of scores like that of the University of Southern California - Van Nuys, and that of genomic tests such as the Oncotype test© DX DCIS (DCIS score) need to be specified. The expected results of several prospective studies could go in the direction of a significant therapeutic de-escalation for the management of DCIS in the years to come. In the meantime, however, it is advisable to remain cautious and the inclusion of patients in clinical trials should be favored.

Population-based study of the effect of preoperative breast MRI on the surgical management of ductal carcinoma in situ

BACKGROUND

Determinants of the use of breast MRI in patients with ductal carcinoma in situ (DCIS) in the Netherlands were studied, and whether using MRI influenced the rates of positive resection margins and mastectomies.

METHODS

All women aged less than 75 years, and diagnosed with DCIS between 2011 and 2015, were identified from the Netherlands Cancer Registry. Multivariable logistic regression analyses were performed, adjusting for incidence year, age, hospital type, DCIS grade and multifocality.

RESULTS

Breast MRI was performed in 2382 of 10 415 DCIS cases (22·9 per cent). In multivariable analysis, patients aged less than 50 years, those with high- or intermediate-grade DCIS and patients with multifocal disease were significantly more likely to have preoperative MRI. Patients undergoing MRI were more likely to have a mastectomy, either as first surgical treatment or following breast-conserving surgery (BCS) in the event of positive margins (odds ratio (OR) 2·11, 95 per cent c.i. 1·91 to 2·33). The risk of positive surgical margins after BCS was similar for those with versus without MRI. The secondary mastectomy rate after BCS was higher in patients who had MRI, especially in women aged less than 50 years (OR 1·94, 1·31 to 2·89). All findings were similar for low- and intermediate/high-grade DCIS.

CONCLUSION

Adding MRI to conventional breast imaging did not improve surgical outcome in patients diagnosed with primary DCIS. The likelihood of undergoing a mastectomy was twice as high in the MRI group, and no reduction in the risk of margin involvement was observed after BCS.

Role of boost radiotherapy for local control of pure ductal carcinoma in situ after breast-conserving surgery: a multicenter, retrospective study of 622 patients

PURPOSE

To evaluate the effect of boost radiotherapy on ipsilateral breast tumor recurrence (IBTR) for ductal carcinoma in situ (DCIS) after breast-conserving surgery and whole breast radiotherapy (WBRT) with or without boost.

METHODS AND MATERIALS

Retrospective, multicentre study of 622 patients (624 tumors) diagnosed with pure DCIS from 1993-2011.

RESULTS

Most tumors (377/624; 60.4%) received a boost. At a median follow-up of 8.8 years, IBTR occurred in 64 cases (10.3%). A higher percentage of patients with risk factors for IBTR received a boost (p < 0.05). Boost was not associated with lower rates of IBTR than WBRT alone (HR 0.75, 95% CI 0.42-1.35). On the univariate analyses, IBTR was significantly associated with tumor size (11-20 mm, HR 2.32, 95% CI 1.27-4.24; and > 20 mm, HR 2.10, 95% CI 1.14-3.88), re-excision (HR 1.76, 95% CI 1.04-2.96), and tamoxifen (HR 2.03, 95% CI 1.12-3.70). Boost dose > 16 Gy had a protective effect (HR 0.39, 95% CI 0.187-0.824). Multivariate analyses confirmed the independent associations between IBTR and 11-20 mm (p = 0.02) and > 20 mm (p = 0.009) tumours, and re-excision (p = 0.006). On the margin-stratified multivariate analysis, tamoxifen was a poor prognostic factor in the close/positive margin subgroup (HR 4.28 95% CI 1.23-14.88), while the highest boost dose ( > 16 Gy) had a significant positive effect (HR 0.34, 95% CI 0.13-0.86) in the negative margin subgroup.

CONCLUSIONS

Radiotherapy boost did not improve the risk of IBTR. Boost radiotherapy was more common in patients with high-risk disease. Tumor size and re-excision were significant independent prognostic factors.

Oncoplastic Level 2 Mammoplasty for Large DCIS: 5-Year Results

BACKGROUND

Oncoplastic surgery (OPS) allows wider resections with immediate breast reshaping by mammoplasty. This study reviews our experience with level 2 mammoplasties in patients with histology-proven pure ductal carcinoma in situ (DCIS).

METHOD

From a prospectively maintained database of 392 consecutive oncoplastic level 2 mammoplasties, 68 patients presented with pure DCIS. Involved margin rates and locoregional recurrence rates were calculated, with 76 months (0-166 months) median follow-up.

RESULTS

The mean pathological tumor size was 34 mm (median 26 mm, range 2-106 mm). The mean resection weight was 191 g (median 131 g, range 40-1150 g). Margins were clear in 58 cases (85.3%) and involved in 10 cases (14.7%). Margins were involved in 1 out of 54 (1.9%) cases with tumor size under 50 mm and in 9 out of 14 (64.3%) cases with tumor size higher than 50 mm (p < 0.001). On multivariable analysis, only tumor size > 50 mm [odds ratio (OR) 95.400; p < 0.001] was independently associated with involved margins. Seven patients had mastectomy. The overall breast conservation rate was 89.4%, and 100% for tumors less than 5 cm. There were three local recurrences. The 5-year cumulative incidence for local recurrence was 5.5% (0-11.5%).

CONCLUSIONS

OPS is a safe solution for large DCIS up to 50 mm, with an involved margin rate of only 1.9%, and can thus reduce the mastectomy rate in this group. As margin involvement significantly increases for tumors larger than 5 cm, better preoperative localization and/or wider excisions are necessary in this group.

Comparing long-term local recurrence rates of surgical and non-surgical management of close anterior margins in breast conserving surgery

PURPOSE

While it is known that histologically involved margins lead to a higher local recurrence rate, re-excision of anterior margins is less common than that of radial margins. However, there are minimal long-term data on the oncological safety of non-surgical management of anterior margins.

PATIENTS AND METHODS

A retrospective study was performed of all patients who underwent breast conserving surgery for breast cancer between 2000 and 2008 at two tertiary referral centres. A close margin was defined as disease within two mm of the resection margin (including disease at the margin).

RESULTS

6922 patients underwent surgery for invasive or in situ breast cancer of whom 277 patients had a close anterior margin alone after breast conserving surgery. Two hundred and twenty patients had non-surgical management of their margins, while 57 had re-excision surgery. Overall, there were 4/57 local recurrences in the surgical management group and 12/220 in the non-surgical management group. The local recurrence-free survival rate at 5 years was 98.2% (1 recurrence, 95% CI 87.8-99.7) in the surgical management group and 97.2% (6 recurrences, 95% CI 93.8-98.7) in the non-surgical management group. At 10 years, the rates were 92.2% (4 recurrences, 95% CI 80.3-97.0) in the surgical management group and 93.9% (12 recurrences, 95% CI 89.4-96.5) in the non-surgical management group. There was no significant difference found in the local recurrence rate between management groups (HR 1.24, 95% CI 0.40, 3.85; p = 0.71).

CONCLUSIONS

Local recurrence rates are acceptable and similar in both the surgically and non-surgically managed groups. Non-surgical management of close anterior margins appears oncologically safe when combined with appropriate adjuvant therapy.

Towards mm-wave spectroscopy for dielectric characterization of breast surgical margins

PURPOSE

The evaluation of the surgical margin in breast conservative surgery is a matter of general interest as such treatments are subject to the critical issue of margin status as positive surgical margins can undermine the effectiveness of the procedure. The relatively unexplored ability of millimeter-wave (mm-wave) spectroscopy to provide insight into the dielectric properties of breast tissues was investigated as a precursor to their possible use in assessment of surgical margins.

METHODS

We assessed the ability of a mm-wave system with a roughly hemispherical sensitive volume of ∼3 mm radius to distinguish malignant breast lesions in prospectively and consecutively collected tumoral and non-tumoral ex-vivo breast tissue samples from 91 patients. We characterized the dielectric properties of 346 sites in these samples, encompassing malignant, fibrocystic disease and normal breast tissues. An expert pathologist subsequently evaluated all measurement sites.

RESULTS

At multivariate analysis, mm-wave dielectric properties were significantly correlated to histologic diagnosis and fat content. Further, using 5-fold cross-validation in a Bayesian logistic mixed model that considered the patient as a random effect, the mm-wave dielectric properties of neoplastic tissues were significantly different from normal breast tissues, but not from fibrocystic tissue.

CONCLUSION

Reliable discrimination of malignant from normal, fat-rich breast tissue to a depth compatible with surgical margin assessment requirements was achieved with mm-wave spectroscopy.

Current Therapeutic Approaches to DCIS

Treatment for ductal carcinoma in-situ (DCIS) has historically been extrapolated from studies of invasive breast cancer. Accepted local therapy approaches range from small local excisions, with or without radiation, to bilateral mastectomies. Systemic treatment with endocrine therapy is often recommended for hormone positive patients. With improvements in imaging, pathologic review, and treatment techniques in the modern era, combined with new information regarding tumor biology, the management of DCIS is rapidly evolving. A multidisciplinary approach to treatment is now more important than ever, with a shift towards de-escalating therapy to reduce treatment related toxicity. This review focuses on nuances of clinical management of DCIS in the modern era, highlighting key differences between DCIS as compared to invasive breast cancer. The American Cancer Society (ACS) currently recommends beginning screening with annual mammograms for women age 45, with the option to start at age 40. As treatment of DCIS has not been shown to impact survival, the USPSTF has more conservative screening recommendations of biennial mammograms from age 50-74. Unlike invasive breast cancer, DCIS is almost exclusively diagnosed by mammographic detection, and lymph node evaluation is not recommended. Pathologic review of biopsy specimens should follow the guidelines of the College of American Pathologists. Surgical management options include breast conservation, mastectomy, or possibly nipple sparing mastectomy, with upfront sentinel lymph node evaluation in the case of mastectomy. Radiation therapy is generally recommended as a component of breast conserving therapy for patients with DCIS, though in some low risk patients, there is trial data to suggest that adjuvant radiation may be omitted. Techniques for minimizing radiation toxicity should always be emphasized. Endocrine therapy is offered to women with hormone positive DCIS who have undergone lumpectomy for risk reduction, and has the benefit of decreasing incidence of events in both the ipsilateral and contralateral breast. More recent studies have explored use of targeted treatments such as trastuzumab in DCIS for HER2 overexpression. Future directions include tailoring therapy based on patient characteristics and tumor biology. With so many different options for treatment, it is also critical to engage in a discussion with the patient to arrive at a treatment decision that balances patient preferences for disease control versus treatment toxicity, financial toxicity, cosmesis, and quality of life.

High-speed Intraoperative Assessment of Breast Tumor Margins by Multimodal Ultrasound and Photoacoustic Tomography

Conventional methods for breast tumor margins assessment need a long turnaround time, which may lead to re-operation for patients undergoing lumpectomy surgeries. Photoacoustic tomography (PAT) has been shown to visualize adipose tissue in small animals and human breast. Here, we demonstrate a customized multimodal ultrasound and PAT system for intraoperative breast tumor margins assessment using fresh lumpectomy specimens from 66 patients. The system provides the margin status of the entire excised tissue within 10 minutes. By subjective reading of three researchers, the results show 85.7% [95% confidence interval (CI), 42.0% - 99.2%] sensitivity and 84.6% (95% CI, 53.7% - 97.3%) specificity, 71.4% (95% CI, 30.3% - 94.9%) sensitivity and 92.3% (95% CI, 62.1% - 99.6%) specificity, and 100% (95% CI, 56.1% - 100%) sensitivity and 53.9% (95% CI, 26.1% - 79.6%) specificity respectively when cross-correlated with post-operational histology. Furthermore, a machine learning-based algorithm is deployed for margin assessment in the challenging ductal carcinoma in situ tissues, and achieved 85.5% (95% CI, 75.2% - 92.2%) sensitivity and 90% (95% CI, 79.9% - 95.5%) specificity. Such results present the potential of using mutlimodal ultrasound and PAT as a high-speed and accurate method for intraoperative breast tumor margins evaluation.

American Society of Breast Surgeons' Practice Patterns After Publication of the SSO-ASTRO-ASCO DCIS Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation

BACKGROUND

The SSO-ASTRO-ASCO consensus guideline on margins for breast-conserving surgery with whole breast irradiation in ductal carcinoma in situ (DCIS) recommended a 2-mm margin. We sought to determine the impact of guideline publication on clinician practice.

METHODS

A total of 3081 members of the American Society of Breast Surgeons (ASBrS) received a survey. Respondents' clinical practice type and duration, guideline familiarity, and margin width preferences before and after publication were assessed. Clinical practice pattern differences before and after publication were investigated using McNemar's test.

RESULTS

A total of 767 (24.9%) of those surveyed responded. Most (92.4%) indicated guideline familiarity. Of those familiar, re-excision preference for DCIS and a positive margin remained the same before (94.4%) and after (94.3%) publication (McNemar's test p = 1.0). Following publication, surgeons were more likely to avoid re-excision to achieve margins wider than 2-mm (82.3% pre versus 87.5% post, p = 0.002). More surgeons performed re-excision for a close margin with pure DCIS (25.9% pre versus 36.5% post, p < 0.001) and with DCIS with microinvasion (DCIS-M) (40.7% pre versus 52.3% post, p < 0.001). For patients with invasive disease with extensive intraductal component (EIC) and a close margin, preference to avoid re-excision was similar (51.2% per versus 55.2% post, p = 0.071).

CONCLUSION

Since guideline publication, surgeons are less likely to perform re-excision to obtain a margin greater than 2-mm and more likely to perform re-excision to obtain a 2-mm margin for both pure DCIS and DCIS-M. Preference to avoid re-excision with a close margin and EIC was similar before and after publication.

Tumor Resection Margin Definitions in Breast-Conserving Surgery: Systematic Review and Meta-analysis of the Current Literature

Worldwide, various guidelines recommend what constitutes an adequate margin of excision for invasive breast cancer or for ductal carcinoma-in-situ (DCIS). We evaluated the use of different tumor resection margin guidelines and investigated their impact on positive margin rates (PMR) and reoperation rates (RR). Thirteen guidelines reporting on the extent of a positive margin were reviewed along with 31 studies, published between 2011 and 2016, reporting on a well-defined PMR. Studies were categorized according to the margin definition. Pooled PMR and RR were determined with random-effect models. For invasive breast cancer, most guidelines recommend a positive margin of tumor on ink. However, definitions of reported positive margins in the clinic vary from more than focally positive to the presence of tumor cells within 3 to 5 mm from the resection surface. Within the studies analyzed (59,979 patients), pooled PMRs for invasive breast cancer ranged from 9% to 36% and pooled RRs from 77% to 99%. For DCIS, guidelines vary between no DCIS on the resection surface to DCIS cells found within a distance of 2 mm from the resection edge. Pooled PMRs for DCIS varied from 4% to 23% (840 patients). Given the differences in tumor margin definition between countries worldwide, quality control data expressed as PMR or RR should be interpreted with caution. Furthermore, the overall definition for positive resection margins for both invasive disease and DCIS seems to have become more liberal.

Article Commentary: Controversies Regarding the Diagnosis and Management of Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) is a premalignant condition, whose incidence is increasing in the current era of widespread screening mammography. While eminently treatable, there are innumerable controversies that surround this disease in terms of its diagnosis and treatment. We discuss these issues and review the data to date regarding this condition which affects roughly 20 per cent of all patients presenting with breast cancer.

Current Approaches to Diagnosis and Treatment of Ductal Carcinoma In Situ and Future Directions

The presentation and treatment of ductal carcinoma in situ (DCIS) has changed substantially over the years. While previously an incidental pathologic finding in more advanced, palpable tumors, the institution of screening mammography has repositioned this disease entity as one largely diagnosed as a non-palpable lesion, often prior to any invasive disease. As DCIS is a precursor to invasive carcinoma, evolution in the approach to treatment has followed in the footsteps of that for invasive disease, including breast conservation therapy, adjuvant radiation, and use of antihormonal therapy. Survival outcomes for DCIS are very high and more recent literature has investigated tailoring therapeutic approaches to avoid overtreatment. Two important areas of ongoing clinical debate concerning overtreatment include use of preoperative MRI and the role of adjuvant radiation. The heterogeneity of the disease makes it difficult to differentiate lesions that would benefit from more aggressive treatment from those in which overtreatment could be avoided. Clinical characteristics, such as histologic appearance, age at diagnosis, and margin status at tumor excision have been established as moderate predictors of disease recurrence, but none has provided strong enough evidence as to guide consensus decisions on adjuvant therapy. Continuing research seeks to define the genetic and molecular characteristics that can predict disease course and serve as the potential targets for novel therapeutic agents. While several markers have shown promise in differentiating tumor aggressiveness, there is still much to be discovered about the precise mechanisms of disease progression and how this can be applied clinically to optimize treatment.

Association of Radiotherapy Boost for Ductal Carcinoma In Situ With Local Control After Whole-Breast Radiotherapy

Importance

The use of a radiotherapy (RT) boost to the tumor bed after whole-breast RT (WBRT) for ductal carcinoma in situ (DCIS) is largely extrapolated from invasive cancer data, but robust evidence specific to DCIS is lacking.

Objective

To compare ipsilateral breast tumor recurrence (IBTR) in women with DCIS treated with vs without the RT boost after breast-conserving surgery and WBRT.

Design, Setting, and Participants

This retrospective analysis pooled deidentified patient-level data from 10 academic institutions in the United States, Canada, and France from January 1, 1980, through December 31, 2010. All patients had newly diagnosed pure DCIS (no microinvasion), underwent breast-conserving surgery, and received WBRT with or without the boost with a minimum of 5 years of follow-up required for inclusion in the analysis. Given the limited events after WBRT, an a priori power analysis was conducted to estimate the DCIS sample size needed to detect the anticipated benefit of the boost. Data were uniformly recoded at the host institution and underwent primary and secondary reviews before analysis. Sample size calculations (ratio of patients who received the boost dose to those who did not, 2:1; α = .05; power = 80%) estimated that 2982 cases were needed to detect a difference of at least 3%. The final analysis included 4131 patients (2661 in the boost group and 1470 in the no-boost group) with a median follow-up of 9 years and media boost dose of 14 Gy. Data were collected from July 2011 through February 2014 and analyzed from March 2014 through August 2015.

Interventions

Radiotherapy boost vs no boost.

Main Outcomes and Measures

Ipsilateral breast tumor recurrence.

Results

The analysis included 4131 patients (median [SD] age, 56.1 [10.9] years; range, 24-88 years). Patients with positive margins, unknown estrogen receptor status, and comedo necrosis were more likely to have received an RT boost. For the entire cohort, the boost was significantly associated with lower IBTR (hazard ratio [HR], 0.73; 95% CI, 0.57-0.94; P = .01) and with IBTR-free survival (boost vs no-boost groups) of 97.1% (95% CI, 0.96-0.98) vs 96.3% (95% CI, 0.95-0.97) at 5 years, 94.1% (95% CI, 0.93-0.95) vs 92.5% (95% CI, 0.91-0.94) at 10 years, and 91.6% (95% CI, 0.90-0.93) vs 88.0% (95% CI, 0.85-0.91) at 15 years. On multivariable analysis accounting for confounding factors, the boost remained significantly associated with reduced IBTR (HR compared with no boost, 0.68; 95% CI, 0.50-0.91; P = .01) independent of age and tamoxifen citrate use.

Conclusions and Relevance

This patient-level analysis suggests that the RT boost confers a statistically significant benefit in decreasing IBTR across all DCIS age groups, similar to that seen in patients with invasive breast cancer. These findings suggest that a DCIS RT boost to the tumor bed could be considered to provide an added incremental benefit in decreasing IBTR after a shared discussion between the patient and her radiation oncologist.

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

INTRODUCTION

Ductal Carcinoma in situ (DCIS) represents 5% of symptomatic and 20-30% of screen detected cancers. Breast conserving surgery (BCS) ± radiotherapy is performed in over 70% of women with DCIS. What constitutes an adequate margin for BCS remains unclear.

METHODS

A single institution follow up study has been conducted of 466 patients with pure DCIS treated by BCS between 2000 and 2010 of whom 292 received whole breast radiotherapy and 167 did not. Patients were selected for radiotherapy based on perceived risk of in breast tumour recurrence (IBTR). Distance to nearest radial margin was measured; 10 patients had a margin width of <1 mm, 94 had widths of 1-2 mm and 362 had widths of >2 mm. There was no association of margin width and the use of radiotherapy.

RESULTS

At a median follow up of 7.2 years there were 44 IBTR (27 DCIS and 17 invasive). There was no evidence that margin widths >2 mm resulted in a lower rate of IBTR than margin widths of 1-2 mm. The actuarial IBTR rates at 5 and 10 years for margins of 1-2 mm were 9.0% (95% CI ± 5.9%) and 9.0% (95% CI ± 5.9%) respectively and for margins of >2 mm were 8.0% (95% CI ± 3.9%) and 13.0% (95% CI ± 3.9%) respectively. Odds Ratio for IBTR 1-2 mm vs >2 mm was 0.839 (95% CI 0.392-1.827) p = 0.846. In a multivariate analysis only DCIS size predicted for IBTR (HR 2.73 p < 0.0001).

CONCLUSION

1 mm appears a sufficient margin width for BCS in DCIS irrespective of whether patients receive radiotherapy.

Therapeutic analysis of Intrabeam-based intraoperative radiation therapy in the treatment of unicentric breast cancer lesions utilizing a spherical target volume model

It is postulated that the outcomes in treating breast cancer with intraoperative radiotherapy (IORT) would be affected by the residual cancer cell distribution within the tumor bed. The three-dimensional (3D) radiation doses of Intrabeam^TM (IB) IORT with a 4-cm spherical applicator at the energy of 50 and 40 kV were calculated. The modified linear quadratic model (MLQ) was used to estimate the radiobiological responses of the cancer cells and interspersed normal tissues with various radiosensitivities. By comparing the average survival fraction of normal tissues in IB-IORT and uniform dose treatment for the same level of cancer cell killing, the therapeutic ratios (TRs) were derived. The equivalent uniform dose (EUD) was found to increase with the prescription dose and decrease with the cancer cell infiltrating distance. For 50 kV beam at the 20 Gy prescription dose, the EUDs are 18.03, 16.49 and 13.56, 11. 29, and 9.28 Gy respectively, for 1.5, 3.0, 6.0, 9, and 15.0 mm of the cancer cell infiltrating distance into surrounding tissue. The dose rate of 50 kV is at least 1.87× higher than that of 40 kV beam. The EUDs of 50 kV beam are up to 15% higher than that of the 40 kV beam. The TR increases with the prescription dose, but decreases with the distance of cancer cell infiltration distance. Average TRs of 50 kV beam are up to 30% larger than that of 40 kV beam. In conclusion, IB-IORT can provide a possible therapeutic advantage on sparing more normal tissue compared with the External Beam IORT (EB-IORT) for shallowly populated unicentric breast lesion. Our data suggest that IB-IORT dose size should be adjusted based on the individual patient's cancer cell infiltrating distance for delivering an effective dose, one dose-fits-all regimen may have undertreated some patients with large cancer infiltrating distance.