Breast-conserving Surgery For Ductal Carcinoma Research Articles

Molecular Expression Assays Improve the Prediction of Local and Invasive Local Recurrence After Breast-Conserving Surgery for Ductal Carcinoma In Situ

Molecular Expression Assays Improve the Prediction of Local and Invasive Local Recurrence After Breast-Conserving Surgery for Ductal Carcinoma In Situ

Positive surgical margins after breast-conserving surgery for ductal carcinoma in-situ: does histologic grade or estrogen receptor status matter?

DCIS has been shown to have a higher rate of positive margins following breast-conserving surgery (BCS) than invasive breast cancer. We aim to analyze certain factors of DCIS, specifically histologic grade and estrogen receptor (ER) status, in patients with positive surgical margins following BCS to determine if there is an association. A retrospective review of our institutional patient registry was performed to identify women with DCIS and microinvasive DCIS who underwent BCS by a single surgeon from 1999 to 2021. Demographics and clinicopathologic characteristics between patients with and without positive surgical margins were compared using chi-square or Student's t-test. We assessed factors associated with positive margins using univariate and multivariable logistic regression. Of the 615 patients evaluated, there was no significant difference in demographics between the patients with and without positive surgical margins. Increasing tumor size was an independent risk factor for margin positivity (P = < 0.001). On univariate analysis both high histologic grade (P = 0.009) and negative ER status (P = < 0.001) were significantly associated with positive surgical margins. However, when adjusted in multivariable analysis, only negative ER status remained significantly associated with margin positivity (OR = 0.39 [95% CI 0.20-0.77]; P = 0.006). The study confirms increased tumor size as a risk factor for positive surgical margins. We also demonstrated that ER negative DCIS was independently associated with a higher rate of positive margins after BCS. Given this information, we can modify our surgical approach to reduce rate of positive margins in patients with large-sized ER negative DCIS.

Multiple Metastases of the Liver and Lung After Breast-Conserving Surgery for Ductal Carcinoma In Situ Without Microinvasion of the Breast: A Case Report and Literature Review.

BackgroundDuctal carcinoma in situ (DCIS) is a non-invasive disease that rarely causes distant metastasis. It is extremely rare for patients diagnosed with DCIS without microinvasion to develop distant metastasis in the absence of ipsilateral or contralateral breast recurrence. This is the first case report of multiple liver and lung metastases from DCIS after breast-conserving surgery and radiotherapy.Case PresentationA 45-year-old woman who was diagnosed with DCIS and received breast-conserving surgery, radiotherapy, and sequential endocrine therapy developed multiple metastases in the liver and lung despite not having bilateral breast recurrence at the 62-month follow-up. Comprehensive advanced breast cancer therapy was administered but did not prevent the progression of metastatic foci in the liver.ConclusionsThis case shows the poor potential outcome in DCIS. Further research should be conducted on metastasis in DCIS; reexamination and monitoring are indispensable for patients diagnosed with DCIS.

Trends in adjuvant therapy after breast-conserving surgery for ductal carcinoma in situ of breast: a retrospective cohort study using the National Breast Cancer Registry of Japan.

Radiotherapy (RT) and endocrine therapy (ET) are standard treatment options after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS). We investigated the national patterns of adjuvant therapy use after BCS for DCIS in Japan. We obtained relevant data of patients diagnosed with DCIS undergoing surgery and treated with BCS between 2014 and 2016 from the Japanese Breast Cancer Registry database. The relationship between the clinicopathologic, institutional, and regional factors, and adjuvant treatment was examined using multivariable analyses. We identified 9516 patients who underwent BCS for DCIS. Overall, 23% received no adjuvant treatment, 71% received RT, 32% received ET, and 26% received combination therapy. The percentages of patients who received ET and combination therapy in 2016 were significantly lower [odds ratio (OR): 0.71, 0.77, respectively] than in 2014. The proportion of RT was low among young or elderly patients (OR: 0.75, 0.44, respectively) and in non-certified facilities (OR: 0.56). The proportion of ET was high in non-certified facilities (OR: 1.58) and among patients with positive margins (OR: 1.62). Combination therapy was higher among patients with positive margins (OR: 1.53). Our study found a distinct adjuvant treatment pattern after BCS for DCIS depending on clinicopathologic factors, year, age, which indicate that physicians provide individualized treatment according to the background of the patients and the biology of DCIS. The facilities and regions remain significant factors of influencing adjuvant treatment pattern.

Predictors of Reexcision following Breast-Conserving Surgery for Ductal Carcinoma In Situ

Reexcision following breast-conserving surgery (BCS) in women with ductal carcinoma in situ (DCIS) results in adjuvant treatment delays, higher health care costs, and undesirable cosmetic outcomes. The purpose of this study is to determine patient, imaging, pathological, and surgical predictors of reexcision following BCS for DCIS. A retrospective review of women with DCIS who had BCS from 2007 to 2016 was conducted. Patient, imaging, pathological, and surgical features, in addition to surgical outcomes, were collected from medical records. Standard statistical tests were used to compare features between patients who did and did not undergo at least one reexcision. A multivariable logistic regression model was fit to assess features associated with reexcision. A total of 547 women (mean age 59years; range 30-88years) diagnosed with DCIS at core needle biopsy underwent BCS. Of all women, 31.6% (173/547) had at least one reexcision. With multivariable analysis, features associated with reexcision included younger patient age (adjusted odds ratio [aOR] 0.98, 95% confidence interval [CI] 0.97-1.0, p = 0.049), African-American race (aOR 2.66, 95% CI 1.13-6.26, p = 0.03), biopsy modality of ultrasound (aOR 2.35, 95% CI 1.22-4.53, p = 0.01), and earlier year of surgery (aOR 0.92, 95% CI 0.86-0.98, p = 0.01). No pathological features of DCIS were associated with reexcision risk. In our cohort of nearly 550 women with DCIS who underwent BCS, 31.6% had at least one reexcision. Features associated with reexcision include younger patient age, African-American race, biopsy modality of ultrasound, and earlier year of surgery.

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.

PurposeTo 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 methodsPatients 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).ResultsForty-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).ConclusionsThe 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.

Treating Second Breast Events After Breast-Conserving Surgery for Ductal Carcinoma in Situ.

Background: Because of screening mammography, the number of ductal carcinoma in situ (DCIS) survivors has increased dramatically. DCIS survivors may face excess risk of second breast events (SBEs). However, little is known about SBE treatment or its relationship to initial DCIS care. Methods: Among a prospective cohort of women who underwent breast-conserving surgery (BCS) for DCIS from 1997 to 2008 at institutions participating in the NCCN Outcomes Database, we identified SBEs, described patterns of care for SBEs, and examined the association between DCIS treatment choice and SBE care. Using multivariable regression, we identified features associated with use of mastectomy, radiation therapy (RT), or antiestrogen therapy (AET) for SBEs. Results: Of 2,939 women who underwent BCS for DCIS, 83% received RT and 40% received AET. During the median follow-up of 4.2 years, 200 women (6.8%) developed an SBE (55% ipsilateral, 45% invasive). SBEs occurred in 6% of women who underwent RT for their initial DCIS versus 11% who did not. Local treatment for these events included BCS (10%), BCS/RT (30%), mastectomy (53%), or none (6%); only 28% of patients received AET. Independent predictors of RT or mastectomy for SBEs included younger age, shorter time to SBE diagnosis, and RT or AET for the initial DCIS. Conclusions: A sizable proportion of patients with SBEs were treated with mastectomy, most especially those who previously received RT for their initial DCIS and those who developed an ipsilateral SBE. Despite the occurrence of an SBE, relatively few patients received AET. Future studies should investigate optimal treatment approaches for SBEs, including the benefit of mastectomy versus lumpectomy for an ipsilateral SBE and the benefit of AET for a hormone-receptor-positive SBE contingent on AET use for the initial DCIS diagnosis.

Which Patients with Left Breast Cancer Should be Candidates for Heart-Sparing Radiotherapy?

PurposeThis study aimed to identify risk factors that have significant interaction with radiation exposure to the heart, and thus to determine candidates for heart-sparing radiotherapy (RT) among women with left breast cancer.MethodsWe identified 4,333 patients who received adjuvant RT following breast-conserving surgery for ductal carcinoma in situ or invasive breast cancer from 1996 to 2010. Incidence rates of cardiovascular disease were compared between left-sided and right-sided RT, and stratified by age and risk factors such as body mass index (BMI), smoking, hyperlipidemia, hypertension, diabetes, administration of anthracycline, and trastuzumab.ResultsIn all patients, the cumulative incidence of cardiovascular disease was greater in patients treated with left-sided RT than in those treated with right-sided RT, but the difference was not significant (p=0.428). Smoking (hazard ratio [HR], 5.991; 95% confidence interval [CI], 2.109–17.022; p=0.002) and hyperlipidemia (HR, 5.567; 95% CI, 3.235–9.580; p<0.001) were the most powerful risk factors for cardiovascular disease. There was no significant factor that further increased the risk of cardiovascular disease after left breast RT compared to right breast RT.ConclusionAlthough hyperlipidemia and smoking are risk factors for cardiovascular disease, they have not been proven to increase the risk of RT-related cardiovascular disease in Korean women.

Patterns of Practice in Radiotherapy for Breast Cancer in Korea.

Adjuvant radiotherapy (RT) is a well-established treatment for breast cancer. However, there is a large degree of variation and controversy in practice patterns. A nationwide survey on the patterns of practice in breast RT was designed by the Division for Breast Cancer of the Korean Radiation Oncology Group. All board-certified members of the Korean Society for Radiation Oncology were sent a questionnaire comprising 39 questions on six domains: hypofractionated whole breast RT, accelerated partial breast RT, postmastectomy RT (PMRT), regional nodal RT, RT for ductal carcinoma in situ, and RT toxicity. Sixty-four radiation oncologists from 54 of 86 (62.8%) hospitals responded. Twenty-three respondents (35.9%) used hypofractionated whole breast RT, and the most common schedule was 43.2 Gy in 16 fractions. Only three (4.7%) used accelerated partial breast RT. Five (7.8%) used hypofractionated PMRT, and 40 (62.5%) had never used boost RT after chest wall irradiation. Indications for regional nodal RT varied; ≥pN2 (n=7) versus ≥pN1 (n=17) versus ≥pN1 with pathologic risk factors (n=40). Selection criteria for internal mammary lymph node (IMN) irradiation also varied; only four (6.3%) always treated IMN when regional nodal RT was administered and 30 (46.9%) treated IMN only if IMN involvement was identified through imaging. Thirty-one (48.4%) considered omission of whole breast RT after breast-conserving surgery for ductal carcinoma in situ based on clinical and pathologic risk factors. Fifty-two (81.3%) used heart-sparing techniques. Overall, there were wide variations in the patterns of practice in breast RT in Korea. Standard guidelines are needed, especially for regional nodal RT and omission of RT for ductal carcinoma in situ.

Ten-year results of applying an original scoring system for addressing adjuvant therapy use after breast-conserving surgery for ductal carcinoma in situ of the breast

PurposeAlthough large-scale randomised clinical trials have established that radiotherapy (RT) - alone or combined with hormonal therapy (HT) - is effective in reducing the risk of ipsilateral breast tumour recurrence (IBTR), overall survival does not seem to be improved by adjuvant therapies. We sought to ascertain whether specific criteria can be adopted to avoid RT with an acceptable rate of IBTR after breast-conserving surgery (BCS) achieving tumour-free margins. Patients and methodsThis non-randomised prospective study concerned the outcome of patients who underwent BCS for ductal carcinoma in situ (DCIS) and were prospectively assessed by means of an established scoring system based on width of free margins in association with age <40, presence of comedonecrosis, high grade, ER negativity and HER2 positivity, to orient the use of any adjuvant therapies. ResultsFrom March 2000 to April 2006, a total of 224 patients were enrolled and followed up for this study. No adjuvant treatment was considered for 76 patients, while 53, 39 and 56 patients received HT alone, RT alone, and RT plus HT, respectively. After a median follow-up of 129.6 months, 25 patients developed an IBTR, corresponding to a yearly rate of 1.138% (95% CI: 0.769–1.684). ConclusionWhen the criteria considered in the present study were applied to address the use of adjuvant therapies, no RT was administered to 57.6% of patients, 33.9% received no adjuvant treatments at all, and the rate of IBTR was low. Our findings support the conviction that the risk/benefit of omitting RT may lean on the side of the latter in selected patients.

Recurrence outcomes after omission of postoperative radiotherapy following breast-conserving surgery for ductal carcinoma in situ of the breast: a multicenter, retrospective study in Korea (KROG 16-02)

To evaluate the loco-regional recurrence (LRR) rate after breast-conserving surgery without postoperative radiotherapy (RT) for ductal carcinoma in situ (DCIS) of the breast. Between 2000 and 2010, 311 DCIS patients from 9 institutions were analyzed retrospectively. The median age was 47 (range, 20-82). The median tumor size was 7mm (range, 0.01-76). Margin width was <1cm in 85 patients (27.3%), and nuclear grade was high in 37 patients (11.9%). Two hundred and three patients (65.3%) received tamoxifen. With a median follow-up of 74months (range, 5-189), there were 11 local recurrences (invasive carcinoma in 6 and DCIS in 5) and 1 regional recurrence. The 7-year LRR rate was 3.8%. On univariate analysis, age and margin width were significant risk factors influencing LRR (p=0.017 and 0.014, respectively). When age and margin width were combined among 211 patients whose margin width were available, the 7-year LRR rates were as follows (p<0.001): (1) 0% in patients with age >50years and any margin width status (n=64), (2) 1.2% in age ≤50years and margin width ≥1cm (n=93), (3) 13.1% in age ≤50years and margin width <1cm (n=54). The LRR rate was very low in selected DCIS patients treated with breast-conserving surgery without postoperative RT. However, adjuvant RT should be considered for those with age ≤50years and margin width <1cm.

Patient Prognostic Score and Associations With Survival Improvement Offered by Radiotherapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ: A Population-Based Longitudinal Cohort Study.

Radiotherapy (RT) after breast-conserving surgery (BCS) is a standard treatment option for the management of ductal carcinoma in situ (DCIS). We sought to determine the survival benefit of RT after BCS on the basis of risk factors for local recurrence. A retrospective longitudinal cohort study was performed to identify patients with DCIS diagnosed between 1988 and 2007 and treated with BCS by using SEER data. Patients were divided into the following two groups: BCS+RT (RT group) and BCS alone (non-RT group). We used a patient prognostic scoring model to stratify patients on the basis of risk of local recurrence. We performed a Cox proportional hazards model with propensity score weighting to evaluate breast cancer mortality between the two groups. We identified 32,144 eligible patients with DCIS, 20,329 (63%) in the RT group and 11,815 (37%) in the non-RT group. Overall, 304 breast cancer-specific deaths occurred over a median follow-up of 96 months, with a cumulative incidence of breast cancer mortality at 10 years in the weighted cohorts of 1.8% (RT group) and 2.1% (non-RT group; hazard ratio, 0.73; 95% CI, 0.62 to 0.88). Significant improvements in survival in the RT group compared with the non-RT group were only observed in patients with higher nuclear grade, younger age, and larger tumor size. The magnitude of the survival difference with RT was significantly correlated with prognostic score (P < .001). In this population-based study, the patient prognostic score for DCIS is associated with the magnitude of improvement in survival offered by RT after BCS, suggesting that decisions for RT could be tailored on the basis of patient factors, tumor biology, and the prognostic score.

Effect of Radiotherapy After Breast-Conserving Surgery for Ductal Carcinoma in Situ: 20 Years Follow-Up in the Randomized SweDCIS Trial

Four randomized studies show that adjuvant radiotherapy (RT) lowers the risk of subsequent ipsilateral breast events (IBEs) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) by approximately 50% after 10 to 15 years. We present 20 years of follow-up data for the SweDCIS trial. Between 1987 and 1999 1,046 women were randomly assigned to RT or not after BCS for primary DCIS. Results up to 2005 have been published, and we now add another 7 years of follow-up. All breast cancer events and causes of death were registered. There were 129 in situ and 129 invasive IBEs. Absolute risk reduction in the RT arm was 12.0% at 20 years (95% CI, 6.5 to 17.7), with a relative risk reduction of 37.5%. Absolute reduction was 10.0% (95% CI, 6.0 to 14.0) for in situ and 2.0% (95% CI, -3.0 to 7.0) for invasive IBEs. There was a nonstatistically significantly increased number of contralateral events in the RT arm (67 v 48 events; hazard ratio, 1.38; 95% CI, 0.95 to 2.00). Breast cancer-specific death and overall survival were not influenced. Younger women experienced a relatively higher risk of invasive IBE and lower effect of RT. The hazard over time looked different for in situ and invasive IBEs. Use of adjuvant RT is supported by 20-year follow-up. Modest protection against invasive recurrences and a possible increase in contralateral cancers still call for a need to find groups of patients for whom RT could be avoided or mastectomy with breast reconstruction is indicated.

Long-term Outcomes of Hypofractionation Versus Conventional Radiation Therapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ of the Breast

Whole-breast radiation therapy (XRT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) may decrease the risk of local recurrence, but the optimal dose regimen remains unclear. Past studies administered 50 Gy in 25 fractions (conventional); however, treatment pattern studies report that hypofractionated (HF) regimens (42.4 Gy in 16 fractions) are frequently used. We report the impact of HF (vs conventional) on the risk of local recurrence after BCS for DCIS. All women with DCIS treated with BCS and XRT in Ontario, Canada from 1994 to 2003 were identified. Treatment and outcomes were assessed through administrative databases and validated by chart review. Survival analyses were performed. To account for systematic differences between women treated with alternate regimens, we used a propensity score adjustment approach. We identified 1609 women, of whom 971 (60%) received conventional regimens and 638 (40%) received HF. A total of 489 patients (30%) received a boost dose, of whom 143 (15%) received conventional radiation therapy and 346 (54%) received HF. The median follow-up time was 9.2 years. The median age at diagnosis was 56 years (interquartile range [IQR], 49-65 years). On univariate analyses, the 10-year actuarial local recurrence-free survival was 86% for conventional radiation therapy and 89% for HF (P=.03). On multivariable analyses, age <45 years (hazard ratio [HR] = 2.4; 95% CI: 1.6-3.4; P<.0001), high (HR=2.9; 95% CI: 1.2-7.3; P=.02) or intermediate nuclear grade (HR=2.7; 95% CI: 1.1-6.6; P=.04), and positive resection margins (HR=1.4; 95% CI: 1.0-2.1; P=.05) were associated with an increased risk of local recurrence. HF was not significantly associated with an increased risk of local recurrence compared with conventional radiation therapy on multivariate analysis (HR=0.8; 95% CI: 0.5-1.2; P=.34). The risk of local recurrence among individuals treated with HF regimens after BCS for DCIS was similar to that among individuals treated with conventional radiation therapy.

Local Relapse After Breast-Conserving Therapy for Ductal Carcinoma In Situ

Adjuvant treatments after breast-conserving surgery (BCS) for ductal carcinoma in situ to prevent local relapse are considered standard of care. However, patient selection to prevent increased morbidity without proven survival benefit remains a challenge. To predict the risk of ipsilateral breast tumor relapse (IBTR) after BCS, the Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram. The aim of this study was to develop our own prediction model for IBTR and to provide an external validation of the MSKCC nomogram. From 1973 to 2010, 467 patients were treated with BCS for ductal carcinoma in situ at the University Hospital Leuven. Clinicopathologic and treatment parameters of all patients were used to create a multivariable model. The predictive value of the model was evaluated using the concordance index (C-index) and concordance probability estimate (CPE). Multiple imputation was used to account for missing data to allow the MSKCC model to be tested on 467 patients. Median follow-up was 7.2 years, with 48 women who developed an IBTR. Omission of adjuvant endocrine therapy, younger age, and positive or close surgical margins were significantly associated with an increased risk of IBTR. The bootstrap-corrected C-index for 10-year prediction by our own model was 0.63 and the CPE was 0.61. The C-index and CPE for the 10-year relapse probabilities predicted by the MSKCC nomogram were 0.66 and 0.61, respectively. Despite the small number of events, the need for multiple imputation, and few patients without radiation, the MSKCC nomogram performance was somewhat better than our model. This shows that the MSKCC nomogram is externally valid. The MSKCC nomogram allows users to integrate the information from 10 different variables to provide a more precise risk stratification than the use of conventional single variables or hazard ratios.

Lapatinib inhibits stem/progenitor proliferation in preclinical in vitro models of ductal carcinoma in situ (DCIS)

Breast-conserving surgery for ductal carcinoma in situ (DCIS) is often combined with irradiation, reducing recurrence rates to 20% within 10 years; however, there is no change in overall survival. Evidence in the invasive breast indicates that breast cancer stem cells (CSCs) are radiotherapy-resistant and are capable of re-initiating a tumor recurrence; hence, targeting CSCs in high risk DCIS patient may improve survival. HER2 is overexpressed in 20% of DCIS and is known to be highly active in breast CSCs; we therefore investigated the effect of Lapatinib on DCIS CSC activity using 2 in vitro culture systems. Two DCIS cell lines DCIS.com (HER2 normal) and SUM225 (HER2 overexpressed) as well as DCIS cells from patient samples (n = 18) were cultured as mammospheres to assess CSC activity and in differentiated 3D-matrigel culture to determine effects within the non-CSCs. Mammosphere formation was reduced regardless of HER2 status, although this was more marked within the HER2-positive samples. When grown as differentiated DCIS acini in 3D-matrigel culture, Lapatinib only reduced acini size in the HER2-positive samples via decreased proliferation. Further investigation revealed lapatinib did not reduce self-renewal activity in the CSC population, but their proliferation was decreased regardless of HER2 status. In conclusion we show Lapatinib can reduce DCIS CSC activity, suggesting that the use of Lapatinib in high-risk DCIS patients has the potential to reduce recurrence and the progression of DCIS to invasive disease.

Indication of sentinel lymph node biopsy with breast-conserving surgery for ductal carcinoma in situ considering lymphatic flow.

192 Background: Ductal carcinoma in situ (DCIS) has been regarded as curable with resection, but axillary lymph node metastases have been reported in 2% of DCIS patients. Even when DCIS has been diagnosed by preoperative core needle biopsy (CNB), 8% to 38% of the patients have been found to have invasive ductal carcinoma (IDC) on the basis of pathological diagnosis after surgical treatment. The indication of sentinel lymph node biopsy (SLNB) and breast-conserving surgery (BCS) for DCIS is still controversial. Methods: SLNB is a standard surgical technique for early breast cancer treatment, and indocyanine green (ICG) fluorescence method is remarkable in terms of the visualization of lymphatic flow. We analyzed the variation in lymphatic drainage routes from the nipple to the SLN (sentinel lymphatic routes) by using the ICG florescence method in early breast cancer patients and investigated the effects on the localization of the tumor to the sentinel lymphatic routes after BCS. Results: From November 2010 to April 2012, we recorded the sentinel lymphatic routes in 118 patients. All the routes passed through the upper outer quadrant (UOQ) area, and there were more than 2 routes in 53 cases. Of these routes, 73% passed through only the UOQ area and 27% passed through the UOQ via the upper inner, lower inner, and/or lower outer quadrant area. Conclusions: We should confirm the sentinel lymphatic routes by using the ICG florescence method before BCS for preoperatively diagnosed DCIS. If the lymphatic routes do not pass over the extent of resection of BCS, we can omit SLNB in the first surgical treatment and await the final pathological result. However, we should perform SLNB in addition to BCS in cases in which the lymphatic routes pass over the tumor in the region except the UOQ area.

217 Adjuvant Radiotherapy After Breast-conserving Surgery for Ductal Carcinoma in Situ – Fifteen-year Results of the EORTC Randomized Phase III Trial 10853

217 Adjuvant Radiotherapy After Breast-conserving Surgery for Ductal Carcinoma in Situ – Fifteen-year Results of the EORTC Randomized Phase III Trial 10853

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

Breast-conserving surgery with radiation therapy has become a standard treatment option in women with localized ductal carcinoma in situ. Re-excision is common in breast-conserving surgery, partly due to lack of consensus on what might constitute an adequate margin. In this study, we aimed to identify potential predictive factors for presence/absence of residual disease after initial breast-conserving surgery. Of 232 cases with a diagnosis of ductal carcinoma in situ without invasive carcinoma at initial biopsy between 2005 and 2009, 108 patients underwent breast-conserving surgery, of which 46 had re-excisions due to close margins (≤ 2 mm). The notable features significantly associated with ductal carcinoma in situ residuum (19/46; 41%) on univariate logistic regression analysis included the number of close margins, the percentage of sections with ductal carcinoma in situ, and the number of duct spaces with ductal carcinoma in situ (no. of ductal carcinoma in situ ducts) at close margins. Only the percentage of sections with ductal carcinoma in situ remained a significant factor associated with outcomes on multivariate analysis, whereas the number of ductal carcinoma in situ ducts at close margins held borderline predictive value (P = .054). Furthermore, logistic regression and classification and regression tree analysis using the 10-fold cross validation method revealed optimal predicting accuracy by using the 3 significant factors in univariate analysis. The final decision tree was constructed by using the number of ductal carcinoma in situ ducts at close margins and the percentage of sections with ductal carcinoma in situ. Thus, these 2 factors represent the most powerful predictors for residual disease on re-excision. Optimal discriminatory power for prediction of absence of residual disease was achieved with cutoffs of 18 ductal carcinoma in situ ducts at close margins and 51.3% sections with ductal carcinoma in situ.

Ramifications of Breast-Conserving Surgery for Ductal Carcinoma in Situ

As more women undergo screening mammography, the number who receive diagnoses of ductal carcinoma in situ (DCIS) has risen. Breast-conserving surgery (BCS) is a reasonable alternative to mastectomy for DCIS, as both approaches yield similar long-term mortality outcomes (JW Oncol Hematol Apr 19 2011); however, the recurrence risk associated with BCS necessitates ongoing surveillance. In a …