Long-term outcomes of adjuvant radiation in elderly Asians with early stage IIA breast cancer after breast-conserving surgery: a population-based study.

Introduction: In some recent studies, breast conserving surgery (BCS) has been reported to improve survival rates compared with modified radical mastectomy (MRM) in early breast cancer. The purpose of this study was to evaluate long term outcome of Korean women with early breast cancer and compare the recurrence rate and overall survival according to operation methods; BCS vs MRM. Method: In this population-based study, we used information from two databases including the nationwide Korean Breast Cancer Registry (KBCR) and Asan Medical Center (AMC). We identified patients from KBCR who were diagnosed breast cancer stage 1-3 between 1998-2012 and were given either BCS or MRM regardless of axillary staging or dissection or use of adjuvant systemic therapy. To minimize confounding bias caused by variables other than operation method, we used exact match pairing of variables such as age, tumor stage and subtypes except for adjuvant radiotherapy. We compared overall survival (OS) and cancer specific survival (CSS) of BCS group and MRM group. As KBCR is multi-centered and online based registry program, we used a single center database to validate the result of KBCR. We selected patients who were diagnosed with breast cancer stage 1-3 between 1998-2008 from AMC and divided them into BCS group and MRM group. We used exact match pairing of all variables except adjuvant radiotherapy in this cohort as well and compared OS, CSS and disease-free survival (DFS). Result: Of 59121 patients who were selected from KBCR, 26581 patients received MRM and 32540 patients received BCS. 18989 patients in each group were remaining after exact match pairing. After exact matching to adjust variables other than operation method, BCS was significantly associated with better OS and CSS compared with MRM. After exact matching HR for OS and CSS were 1.47 [0.36-1.59 p<0.001], 1.37 [1.20-1.57 p<0.001] respectively. Of 8710 patients who from AMC, 2490 patients were excluded as they had unknown variables we needed to know for exact matching. 3095 patients received MRM and 3125 patients received BCS. 1790 patients in each group were remaining after exact match pairing. In this cohort after exact BCS was also significantly associated with better OS, CSS and DFS compared with MRM. After exact matching HR for OS, CSS and DFS were 1.64 [1.30-2.06 p<0.001], 1.71 [1.33-2.20, p<0.001], 1.37 [1.14-1.64, p<0.001] respectively. Median follow up was 88.6 month before matching and 89.2 month after matching. Conclusion: When we adjusted confounding variables by exact matching BCS showed better overall and cancer specific survival and in AMC database better recurrence free survival compared to MRM in early breast cancer patients. These results suggest that BCS is at least equivalent to mastectomy in terms of recurrence free survival and overall survival and may affect treatment decisions in early breast cancer patients. Citation Format: Hakyoung Kim, Sei Hyun Ahn, Byung Ho Son, Jong Won Lee, Il Yong Chung, Beom Seok Ko, HeeJeong Kim, Jisun Kim, Young Ju Lee, Yungil Shin, Soojeong Choi, Ho Hyun Ryu, Sae Byul Lee. Long-term outcomes after breast conserving surgery compared with mastectomy in early breast cancer in Korea [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-20.

10 year survival after breast-conserving surgery plus radiotherapy compared with mastectomy in early breast cancer in the Netherlands: a population-based study

Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: an overview of the randomised trials

Localising the Tumour Bed in Breast Radiotherapy

A recent study found that in women with stage I or II breast cancer, breast-conserving therapy (BCT) was associated with improved disease-specific survival compared with mastectomy (Cancer. 2013;119:1402-1411). It has been believed for years that these 2 approaches to the locoregional treatment of early breast cancer are equivalent, and thus the percentage of women choosing BCT has increased. However, for unclear reasons, mastectomy is being chosen more often among certain groups of patients such as younger women, those with in situ cancer, and those living in more affluent areas (J Clin Oncol. 2010;28:e155-e157). Researchers set out to investigate whether the similar survival rates of BCT and mastectomy noted in randomized trials hold true for the general population, and to determine whether there is a subgroup that benefits from one approach versus the other. “In this observational study of over 112,000 women treated with early-stage breast cancer, women undergoing lumpectomy and radiation had equivalent, and in some subgroups superior, breast cancer-specific survival compared to women undergoing mastectomy,” says E. Shelley Hwang, MD, MPH, chief of breast surgery at Duke University Medical Center in Durham, North Carolina. Dr. Hwang and her colleagues identified cases of stage I or II breast cancer from the California Cancer Registry for patients diagnosed between 1990 and 2004. Women who were treated with either a lumpectomy followed by radiation therapy or mastectomy were eligible; women who had undergone a lumpectomy without radiation or a mastectomy with radiation were excluded. Overall, a total of 112,154 eligible women were found: 55% underwent BCT and 45% underwent mastectomy. The median follow-up was close to 10 years. BCT rates increased from 37% between 1990 and 1992 to 62% between 2002 and 2004. The 5-year overall survival (OS) rate of the entire cohort was 89.3%, and the disease-specific survival (DSS) rate was 94.4%. Cox multivariate analysis was performed to compare survival between 4 groups: 1) those aged 50 years or older with hormone receptor (HR)-negative disease; 2) those aged 50 years or older with HR-positive disease; 3) those aged younger than 50 years with HR-negative disease; and 4) those aged younger than 50 years with HR-positive disease. Human epidermal growth factor receptor 2 (HER2) status was not considered, as it was not widely available during the study period. In all the groups, BCT was associated with improved OS compared with mastectomy. The largest benefit was observed in the group of women aged older than 50 years who had HR-positive disease (hazard ratio, 0.81). The DSS benefit was also most prominent in this group, with a hazard ratio of 0.87. The smallest benefit for BCT was noted in the women aged younger than 50 years with HR-positive tumors (hazard ratio, 0.93). A large observational study recently compared outcomes of mastectomy and breast conserving therapy among women with early stage breast cancer. After adjusting for tumor grade, percentage of positive lymph nodes, race, socioeconomic status, tumor size, age at diagnosis, and year of diagnosis, the women treated with BCT still had significantly higher OS and DSS rates. Analysis was performed to examine whether comorbidities had an effect on surgical choice and outcomes. Heart disease, chronic respiratory disease, and cerebrovascular disease were considered. BCT was associated with significantly lower 3-year mortality rates from all causes, except for breast cancer. Kaplan-Meier survival estimates demonstrated statistically significantly increased OS and DSS for BCT versus mastectomy. In this analysis, the increased survival advantage of BCT was again found to be greatest among women aged 50 years and older with HR-positive disease. When examining the tumor size and surgical approach used, the survival benefit was larger among patients with T1 tumors compared with those with T2 tumors in all groups, but OS was still better in the BCT group among women with T2 tumors. Dr. Hwang and her colleagues state that the strengths of this study include a large, diverse population-based data set representing the state of California; a lengthy follow-up period; excellent reliability of data; and a more modern cohort than the randomized controlled trials comparing lumpectomy and mastectomy that were conducted over 30 years ago. However, the study was observational, and therefore the groups were not randomized. Researchers tried to control for all major factors known to impact breast cancer-specific survival, but there could be some unmeasured confounders associated with the choice of mastectomy that were not accounted for in the analysis and thus not controlled for in the study. In addition, the authors caution that as an observational study, causality could not be inferred. “This study by Hwang and colleagues shows there is no benefit of mastectomy measured in risk of local recurrence or survival,” says Stephen Edge MD, chief of breast surgery at Roswell Park Cancer Institute in Buffalo, New York. “Their findings that survival is better with BCT must be interpreted with caution as this was not a randomized trial. My review suggests that decisions they made in defining the study population and other methodologic issues could have biased the results towards a benefit from BCT where that benefit may or may not exist, a significant problem using population data. However, they clearly showed no worse outcome with BCT, thereby reaffirming the unequivocal findings from randomized controlled clinical trials with mature follow-up.” Since there are no data, including this study, that show mastectomy to be superior to BCT, it is interesting that there has been a recently reported trend showing an increased uptake of mastectomy over BCT by women with early-stage breast cancer. “The reasons underlying this trend are doubtless multifactorial; these include better breast reconstruction techniques, increased use of MRI, and increased awareness of breast cancer and its consequences. However, the trend is particularly fascinating because the segment of the population opting for more surgery—not only mastectomy, but bilateral mastectomy—are generally younger, more educated women with better access to health care and smaller, earlier cancers. This indicates that greater overall health literacy is associated with more surgery, despite the lack of evidence that supports better outcome with more surgery,” says Dr. Hwang. Dr. Edge agrees that for unknown reasons some women are asking for, and their surgeons are performing, more mastectomies. “Contributing factors include misinformation leading to fear. This is an area where thoughtful patient support is needed. Surgery is not a good treatment for unfounded fears,” he says. Future research could include examining the relationship between HER2 status and surgery and outcomes. Because these data have been recorded in the California Cancer Registry since 2006, this analysis should be possible. “This study points to the importance of large data sets and how they can be used to look at questions for which further randomized studies are not appropriate,” says Dr. Hwang. “Of course, there will always be cases in which a mastectomy is a better option, but for most women who have the choice, doing less may be more.”

Abstract: Comparative 10-Year Survival Analysis of Breast-Conserving Surgery Versus Mastectomy in Early-Stage Breast Cancer for Young Patients Introduction:Pivotal studies established that breast-conserving surgery (BCS) followed by radiotherapy is as effective as mastectomy for breast cancer treatment. Recent retrospective population-based studies suggest a potential overall survival benefit for BCS over mastectomy, particularly in older patients. In younger patients this benefit was less clear. Therefore, we evaluated 10-year overall survival and distant metastasis-free survival in patients with early breast cancer, aged up to 55 years, comparing BCS with radiotherapy to mastectomy. Methods:We conducted a retrospective cohort study using data from UZ Leuven including female patients aged up to 55 years, diagnosed with early invasive breast cancer (pT1-2, N0-1; for those receiving neo-adjuvant therapy cT1-2, cN0-1 and ypT0-2, N0-1) between 2008 and 2012. Patients underwent either mastectomy (with or without radiotherapy) or BCS with radiotherapy. Decision for type of surgery was made based on tumor and patient characteristics, as well as patients’ preference. All received systemic adjuvant therapy according to prevailing standard of care at that time. Outcomes included overall survival and distant metastasis-free survival. The Kaplan-Meier method estimated crude survival rates 10 years after diagnosis. Multivariable Cox proportional hazard regression, incorporating propensity scores, was used to correct for confounding factors (age, cT, cN, pT, pN, molecular subtype, grade, and multifocality). Results:Of 986 eligible patients, 407 underwent mastectomy (73.5% postop radiotherapy) and 579 received BCS (100% postop radiotherapy). Average age at diagnosis was 46,4 years and median follow-up time was 12,7 years. Patients who received a mastectomy had larger tumors and were more frequently node positive. Furthermore, these tumors were often of higher grade and multifocal. Of the patients in the mastectomy group 14.0% had triple negative tumors, compared to 15.7% in the BCS group. However, the patients in the mastectomy group had more HER2-positive tumors (15.2% vs 8.6% for BCS). Adjuvant chemotherapy was administered to 60.1% of patients who underwent mastectomy compared to 41.6% of patients who had breast-conserving surgery (BCS). Alternatively, neo-adjuvant chemotherapy was given to 5.6% of patients in the mastectomy group, whereas 2.2% of patients in the BCS group. Overall unadjusted overall survival rates (crude survival, not corrected for confounding factors) were 85.5% for mastectomy and 92.1% for BCS. Adjusted analysis showed no significant difference in overall survival, though it did seem to show a trend favoring BCS (HR 0.52 [95% CI 0.36-0.77]; p=0.001; adjusted HR 0.67 [0.43-1.06]; p=0.09). This trend was less clear for distant metastasis-free survival (DMFS HR 0.65 [95% CI 0.46-0.92]; p=0.01; adjusted HR 0.88 [95% CI 0.59-1.32]; p=0.56). Conclusion:Consistent with previous cohort studies, our single-center study suggests a trend favoring BCS over mastectomy in terms of overall survival for patients up to 55 years old. This trend, however, was not statistically significant after adjusting for confounding factors, highlighting the need for further investigation of this population using larger cohorts. Citation Format: Babette Salaets, Annouschka Laenen, Thais Baert, Adinda Baten, Francoise Derouane, Christine Desmedt, Sileny Han, Hilde Janssen, Ines Nevelsteen, Ann Smeets, Maxime Van Houdt, Jelle Verhoeven, Caroline Weltens, Hans Wildiers, Patrick Neven. Comparative 10-Year Survival Analysis of Breast-Conserving Surgery Versus Mastectomy in Early-Stage Breast Cancer for Young Patients [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P4-07-01.

Background: The National Accreditation Program for Breast Centers (NAPBC), in a 2014 statement of standards, endorsed breast conservation surgery (BCS) for women with AJCC stage 0,I, or II breast cancer, with a target of 50% BCS. Women comprise the fastest growing segment of Veteran's Health Administration (VA) enrollees, and have high rates of trauma exposure including military sexual trauma (MST). The VA conducts universal screening of all Veterans for MST. Implications for medical care, e.g. an increased rate of hysterectomy among survivors of MST, have been reported. While the numbers of breast cancers treated in VA are relatively small compared to non-VA centers, a trend toward decreasing rates of BCS in VA from 2000-2006 has been reported. Reasons for declining rates of BCS within VA, and the lower rates of BCS in the VA compared to the private sector remain unclear. The objective of this study was to identify determinants of mastectomy versus BCS in women Veterans with early stage breast cancer and to examine whether history of MST was associated with choice of mastectomy versus BCS. Methods: As a quality improvement study, we conducted a retrospective review of all early-stage (0,I,II) female breast cancer patients identified in the tumor registry between 2006-2015 at one Northeastern VA to determine rates of mastectomy and BCS. Through chart review, we examined potential determinants of BCS including age, stage, distance from treating VA facility, genetic testing, contralateral prophylactic mastectomy, and reconstructive surgery. History of MST was documented through chart review. Analyses were performed using unpaired t-test for age and distance from treatment facility and Fisher's exact test for significance comparing history of MST between surgical groups. Results: 70 women with early stage breast cancer were eligible for BCS. Of these, 39 underwent BCS and 31 underwent mastectomy (55% rate of BCS). Age and distance to treating VA were not significant. Women who underwent mastectomy were on average younger (p=0.21) and lived farther away (p =0.42) and were more likely to undergo genetic testing. Of the women who underwent genetic testing (10/70), none had mutations. The biggest difference seen between surgical groups was in history of MST, with women in the mastectomy group having more than twice the prevalence of MST, 58%, vs 31% in the BCS group (p = 0.0154 ). Patient characteristics by type of surgery performed BCS N=39Mastectomy n=31Age (mean)63.559.3Distance from VA56.7 miles67.7 milesGenetic testing (no mutations found)4 (10%)6 (19%)Reconstructive surgery05Prophylactic contralateral mastectomy011MST11(28%)18(58%) Conclusion: These data suggest that MST is associated with choice of mastectomy over BCS. MST results in poor body image which may impact decisions about breast surgery. Trauma-informed strategies for counseling women about options for surgical management of early stage breast cancer may be needed to ensure that women with MST and other forms of trauma pursue evidence-based cancer treatment. Further work with a larger cohort is needed to better understand these findings. Citation Format: Oshry LJ, Naomi K, Megan GR. Military sexual trauma is associated with an increased prevalence of mastectomy versus breast conserving surgery in a population of female veterans with early stage breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-15-01.

A Toast to the Silver Anniversary of Clinical Oncology: A Quarter of a Century of Advances in Evidence-based Radiation Dose Fractionation

Background Outcomes for women with early breast cancer have continually improved. A biologic signature to identify those patients that have elevated ipsilateral breast event (IBE) risk after breast conserving surgery (BCS) treated with or without radiation therapy (RT) is needed. More aggressive systemic or surgical options may be warranted for patients with elevated risk while BCS alone may be an option for very low risk patients. We report early results for a biologic signature interrogating critical pathways. Material and Methods This study includes patients from Uppsala University Hospital and Västerås Hospital diagnosed with early breast cancer, 20mm or less, treated surgically between 1987 and 2004. Women with lymph node metastases or treated with mastectomy or chemotherapy were excluded. A panel of biomarkers (HER2, PR, Ki67, COX2, p16/INK4A, FOXA1 and SIAH2) were assayed and scored in PreludeDx's CLIA lab by board-certified pathologists. There were 171 eligible patients with biomarker data; 131 received RT and 9 received hormone therapy. Risk groups were calculated using biomarkers and clinical factors age and size. Absolute 10-year IBE risk was assessed using Kaplan-Meier survival analysis. Hazard ratios (HR) were determined using Cox proportional hazards analysis. Results There were 49 IBEs recorded. The biologic signature classified 41% of women into a low risk group. Patients in the elevated risk group had a significantly increased risk of 10-year IBE compared to those in the low risk group (Table 1). The HR for elevated vs. low risk group was 5.0 [2.2-11], p<0.001, in a multivariate analysis of risk group and RT. Patients in the elevated risk group treated with BCS and RT had an 18% apparent risk difference in 10-year IBE. Patients in the low risk group had similar low 10-year risks of IBE, when treated with BCS, with or without RT. The low risk women had somewhat increased prevalence of low grade tumors (58% vs. 41%). Women with low grade and small tumors (up to 10mm) were classified into both risk groups (54% low vs. 38% elevated risk). Table 1:10-year Risks of Local Recurrence by Risk GroupBCS without RTBCS plus RTN10-Yr local IBE Risk, 95%CIn10-Yr local IBE Risk, 95%CIBaseline4028%, [11% – 31%]13122% [12% – 24%]Low Risk Group196% [0%-14%]516% [0%-12%]Elevated Risk Group2149% [20%-68%]8031% [21% - 41%] Discussion A biologic risk signature identified early breast cancer patients with low and elevated 10-year IBE risks for women treated with BCS with or without RT and no chemotherapy. Approximately 40% of women were classified into a low risk group with a 0.5% IBE risk per year. Women in the elevated risk group had 3% to 5% IBE risks per year depending on treatment. Treatment for women in this observational study was neither randomized nor strictly rules based. With further prospective validation, the biologic signature identified herein may provide a tool enabling improved management for women diagnosed with early breast cancer. Citation Format: Bremer T, Savala J, Leesman G, Wärnberg F, Sund M, Wadsten C, Whitworth PW. A biologic signature to predict ipsilateral breast event risk at 10 years for early breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-57.

Long-term overall survival of patients who undergo breast-conserving therapy or mastectomy for early operable HER2-Positive breast cancer after preoperative systemic therapy: an observational cohort study

Background: Some population-base studies have reported similar or improved survival for breast-conserving surgery (BCS) plus radiotherapy compared with mastectomy (Mx) in early breast cancer [PMID: 22373563, 27344114]. Among the screening detected early breast cancer, ultrasound (US) could detect more invasive non-palpable breast cancer (NPBC) with positive lymph nodes in hospital-based asymptomatic Chinese women, who could achieve comparable 10-year DFS and OS as mammography (MG)-detected NPBC [2016 SABCS P5-02-05, PMID: 27689334]. However, there is little data about the surgical outcomes of BCS verse Mx in the low-risk screening detected NPBC with US as the initial imaging test. Methods: From 2001 to 2017, 6,423 consecutive asymptomatic women underwent mammography or ultrasound guided biopsy in Peking Union Medical College Hospital. Among them, 1130 NPBC including 914 US-detected and 216 MG-detected NPBC were diagnosed and treated. There were 349 (30.9%) patients underwent BCS including 286 (25.3%) patients received radiation therapy and 63 (5.6%) elderly patients (>70 years) who did not. The clinicopathological features, treatment choice, 10-year disease-free survival (DFS) and overall survival (OS) were compared between breast conservingsurgery (BCS) versus mastectomy(Mx) in all NPBC and between the US-detected and MG-detected NPBC. Result: Compared to those who received BCS, the 781 (69.1%) patients who underwent Mx had more cancers with relatively higher histologic grade (p=0.003), positive lymph node (18.8% vs 12.0%, p=0.005), ER-negative (22.5% vs 11.5%, p<0.001), PR-negative (29.6% vs 16.3, p<0.001), Her2-positive (16.3% vs 8.9%, p=0.001), and received chemotherapy (37.6% vs 28.7%, p=0.003). The breast conserving rates of US-NPBCwere higher than that of MG-NPBC (32.6% vs 23.6%, p=0.010), but the breast conserving rates were similar between ductal carcinoma in situ (DCIS) and invasive cancers. The 10-year DFS and OS were similar among BCS with radiation therapy, BCS without radiation therapy and Mx as well as among US-NPBC with BCS, US-NPBC with Mx, MG-NPBC with BCS and MG-NPBC with Mx. However, MG-NPBC with Mx had favorable 10-year DFS than that of MG-NPBC with BCS (p=0.041). Table 1.Kaplan-Meier estimated 10-year DFS and OS of all NPBC§Patients (No.)NPBC GroupNumber (%)10-year DFS (%)P value10-year OSP valueAll NPBC (1130)BCS without Radiotherapy63 (5.6)85.00.10592.30.722 BCS with Radiotherapy286 (25.3)92.7 99.5 Mastectomy781 (69.1)93.2 98.7 All NPBC (1130)US+BCS298 (26.4)90.40.24896.30.542 US+Mx616 (64.5)92.4 98.4 MG+BCS51 (4.5)90.3 100.0 MG+Mx165 (14.6)96.1 100.0 § Kaplan-Meier survival curves would be displayed in the poster. Conclusion: The 10-year DFS and OS of breast conserving surgery versus mastectomy were similar among all NPBC patients. As the current initial imaging test, US-detected NPBC patients would receive significantly more BCS compared to MG. There was no significant difference in surgical outcomes among BCS and Mx in US-detected NPBC. However, among MG-detected NPBC, patients with Mx reached a better DFS but a similar OS than those with BCS. The radiation therapy could be safely omitted in the elderly patients (>70 years) with NPBC. Citation Format: Yao R, Pan B, Xu Y, Zhou Y, Zhu Q, Zhang J, Wu H, Mao F, Lin Y, Shen S, Sun Q. Survival outcomes of breast conserving surgery versus mastectomy for ultrasound detected non-palpable breast cancer in hospital-based screening among Chinese women [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-30.

BMI is an independent prognostic factor for late outcome in patients diagnosed with early breast cancer: A landmark survival analysis

Oncoplastic surgery (OPS) has emerged as a new approach for extending breast conserving surgery (BCS) possibilities, reducing both mastectomy and re-excision rates, while avoiding breast deformities. OPS is based upon the integration of plastic surgery techniques for immediate reshaping after wide excision for breast cancer. This is a prospective feasibility cohort study of oncoplastic breast surgery after neoadjuvant chemotherapy that was carried at the National Cancer Institute, Cairo University and included 70 patients. The primary outcome was the local recurrence rate. Secondary outcomes included survival and margins obtained as well as cosmetic outcomes. Survival analysis was performed. Oncoplastic breast surgery did not compromise oncologic safety in the patients included in the study. It even allowed wider margins of resection which could be associated with better oncologic outcomes. At the same time, it gave a better cosmetic outcome and therefore higher patient satisfaction. Oncoplastic breast surgery includes a wide spectrum of surgical techniques, ranging from the basic level I techniques in breast conserving surgery to the more complex procedures of level II which are broadly classified into volume replacement (therapeutic mammoplasty) and volume displacement procedures. We suggest that oncoplastic breast surgery techniques should be the standard of care in breast surgery. They are the basis for breast conserving surgery techniques in early breast cancer. In our experience, oncoplastic surgery is feasible in locally advanced tumours after downstaging with neoadjuvant chemotherapy without compromising the oncologic safety.

Background: Breast conserving surgery (BCS) is a standard procedure for patients with early stage breast cancer. However, as the objective of BCS is to obtain both local control and a cosmetic outcome, it may lead to unsatisfying cosmetic results when the volume of resected tissue is large in order to secure an adequate oncological safety margin. Autologous flaps or artifact implants are commonly used when performing a replacement for a defect in the breast during BCS. Oxidized regenerated cellulose (ORC) is composed primarily of vegetable nitrocellulose and was originally developed as a styptic for surgery. We expected that the ORC would help induce granulation and fibrous tissue with reactive tissue fluid, and finally ORC would prevent adhesion between skin and pectoralis major muscle. In this study, we focused on short-term cosmetic outcomes after volume replacement with ORC after BCS. Materials and Methods: Inclusion criteria of this study were the patients with early breast cancer indicated BCS that did not required breast reconstruction, or the patients who did not wish to undergo breast reconstruction with autologous flaps after BCS. We evaluated the cosmetic outcome of volume replacement with ORC after BCS, and also examined factors that may have influenced the results. The cosmetic outcomes of these patients were evaluated using scores based on the criteria of the Japan Breast Cancer Society. Results: Ninety-four patients who underwent this procedure between January 2010 and August 2012 were reviewed. We evaluated cosmetic scores with regards to several clinical factors and the occurrence of complications after this procedure. The mean score of the cosmetic outcome of all patients was 9.5 points out of 12 points. Thirty-seven patients were categorized as “Excellent”, 34 were “Good”, 22 were “Fair”, and 1 was “Poor”. Patient age, body mass index, weight of the specimen, and ORC amount were not significantly different between patients with favorable cosmetic scores and those without. Table 1. Univariate analyses of clinical factors according to the cosmetic outcome E/G* (n = 71)F/P# (n = 23)P valueAge52.5±12.656.0±10.30.23Body mass index22.0±3.723.3±4.10.15Specimen weight54.0±23.961.4±39.10.27ORC amount$3.2±1.23.2±1.20.95Values are expressed as the mean±SD. *Categorized as “Excellent” and “Good”. #Categorized as “Fair” and “Poor”. $ORC amount used for volume replacement. However, the weight of the removed specimen was slightly higher in patients with an unfavorable cosmetic score. Although acute dermatitis and eczema was observed in 15% and 3% of patients, all of them were improved with conservative treatment. Cosmetic scores were significantly higher in patients without complications than in patients with complications. Table 2. Cosmetic scores between patients with and without acute complications Cosmetic scores (mean±SD)P valusWithout9.8±2.00.003With8.0±2.4 Conclusions: ORC replacement after BCS is a simple and reliable procedure. The selection of indication and prevention of complications are important for obtaining a better cosmetic outcome. To our knowledge, this is the first report to cosmetically evaluate a relatively large number of patients that have undergone ORC replacement after BCS. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-06.

Background: Neoadjuvant chemotherapy (NAC) is an established treatment option in early breast cancer. NAC potentially downstages the tumor and, combined with oncoplastic techniques, may increase the eligibility for breast conserving surgery (BCS). NAC can also result in less surgical morbidity of the axilla if axillary clearance can be avoided. In addition, preoperative medical treatment allows for a thorough evaluation of treatment response and lays the foundation for adjuvant treatment decisions. The aim of the study was to prospectively estimate the proportion of BCS post NAC and the relation to well-defined factors associated with BCS post NAC. Materials and methods: This observational prospective cohort study included 226 patients in the SCAN-B neoadjuvant cohort (Clinical trials: NCT02306096) receiving NAC between 2014 and 2019. Eligibility for BCS was based on the assessment of the surgeon at time of diagnosis and again post NAC. All the covariables were defined at time of diagnosis from mammograms and core needle biopsies, except for pathological complete response (pCR). Treatment generally consisted of 6 to 7 three-weekly treatment cycles of anthracycline- and taxane-based chemotherapy, given in sequence. In HER2-positive disease, HER2-directed antibodies were added as appropriate.The primary aim was to estimate the proportion of BCS after NAC and the secondary aim was to evaluate factors as predictors of BCS, including gene expression and surrogate molecular subtypes (St. Gallen), breast density, and other putative modifying factors.Uni- and multivariable logistic regression analysis were performed including covariates of clinical relevance and/or associated with the outcome measures (BCS versus mastectomy). Results: The BCS rate increased during the study years, from 37% to 52%. pCR was achieved in 69 patients (30%). Predictors with a negative association to BCS were larger tumor size on mammography (T3 vs T1) (odds ratio (OR)=0.20, 95% confidence interval (CI) [0.06,0.64]), lack of visibility on ultrasound (OR=0.08, 95% CI [0.001,0.63]), lobular histological subtype vs other subtypes (OR=0,20, 95% CI [0.06,0.61)). Factors positively associated with BCS were benign axillary lymph node status (OR=2.26, 95% CI [1.26,4.06]) and surrogate molecular subtypes; patients with triple negative and HER-2 positive tumors had the highest probability of receiving BCS, 65% and 54%, respectively. Gene expression subtypes had a similar trend of being associated with BCS; patients with basal like and HER-2 enriched tumors had higher odds ratio for BCT than patients with luminal subtypes (Table 1). In the multivariable logistic regression analysis, tumor size on mammography and axillary status had the strongest association to BCS (OR=0.95, 95% CI [0.92,0.98] and OR=2.08, 95% CI [0.99,4.35], respectively). Conclusions: Our study shows that the rate of BCS after NAC increased over the study years, but mastectomy rate in the study was still close to 50%. With increasing number of patients achieving pCR after NAC, the BCS rate should be possible to increase further. Predictors of BCS after NAC were identified, and benign axillary lymph nodes and smaller tumor size defined at time of diagnosis were the strongest predictors of BCS, supporting that initial tumor stage was important for the choice of surgery after NAC. Table 1. Baseline characteristics and univariable logistic regression. 1. Determined by biopsy or sentinel node. 2. Only tumors visible on mammography. 3. Defined as ypT0/ypTis/ypN0. Citation Format: Kim Gulis, Julia Ellbrant, Pär-Ola Bendahl, Tor Svensjö, Johan Vallon-Christersson, Ida Dalene Skarping, Niklas Loman, Lisa Rydén. Save the breast after neoadjuvant therapy – identifying radiological and tumor related factors of importance for breast conserving surgery after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-09-06.