Margins in Breast-Conserving Surgery After Neoadjuvant Therapy.

To compare the survival outcomes associated with clinical and pathological response in pancreatic ductal adenocarcinoma (PDAC) patients receiving neoadjuvant chemotherapy (NAC) with FOLFIRINOX (FLX) or gemcitabine/nab-paclitaxel (GNP) followed by curative-intent pancreatectomy. Newer multiagent NAC regimens have resulted in improved clinical and pathological responses in PDAC; however, the effects of these responses on survival outcomes remain unknown. Clinicopathological and survival data of PDAC patients treated at 7 academic medical centers were analyzed. Primary outcomes were overall survival (OS), local recurrence-free survival (L-RFS), and metastasis-free survival (MFS) associated with biochemical (CA 19-9 decrease ≥50% vs <50%) and pathological response (complete, pCR; partial, pPR or limited, pLR) following NAC. Of 274 included patients, 46.4% were borderline resectable, 25.5% locally advanced, and 83.2% had pancreatic head/neck tumors. Vein resection was performed in 34.7% and 30-day mortality was 2.2%. R0 and pCR rates were 82.5% and 6%, respectively. Median, 3-year, and 5-year OS were 32 months, 46.3%, and 30.3%, respectively. OS, L-RFS, and MFS were superior in patients with marked biochemical response (CA 19-9 decrease ≥50% vs <50%; OS: 42.3 vs 24.3 months, P < 0.001; L-RFS-27.3 vs 14.1 months, P = 0.042; MFS-29.3 vs 13 months, P = 0.047) and pathological response [pCR vs pPR vs pLR: OS- not reached (NR) vs 40.3 vs 26.1 months, P < 0.001; L-RFS-NR vs 24.5 vs 21.4 months, P = 0.044; MFS-NR vs 23.7 vs 20.2 months, P = 0.017]. There was no difference in L-RFS, MFS, or OS between patients who received FLX or GNP. This large, multicenter study shows that improved biochemical, pathological, and clinical responses associated with NAC FLX or GNP result in improved OS, L-RFS, and MFS in PDAC. NAC with FLX or GNP has similar survival outcomes.

BackgroundWith limited sample sizes and single-institution designs, how complete response (CR) after neoadjuvant chemotherapy (NAC) influences breast conserving surgery (BCS) and its value in prognosis are not clear.MethodsA systematic research review was conducted using electronic database. The rate of clinical complete response (cCR) in BCS after NAC and these pathological CR (PCR) and non-pCR BCS patients’ local recurrence-free survival (LRFS), distance recurrence-free survival (DRFS), overall survival (OS), and disease-free survival (DFS) rates were collected. A pooled analysis was performed using a fixed or random effects model and a Q test to determine heterogeneity.ResultsSixteen studies with a total of 4639 patients were included. The pooled data revealed that cCR patients compared with non-cCR patients had significantly higher rates of BCS, with a summary estimate odds ratios (OR) of 4.54 (95% CI 2.03–10.17). The pooled data revealed that BCS patients who achieved pCR after NAC had significantly lower rates of LRFS (RR = 0.59, 95% CI 0.38–0.92) and DRFS (RR = 0.27, 95% CI 0.13–0.55). Better DFS (RR = 0.09, 95% CI 0.04–0.25) and OS (RR = 0.36, 95% CI 0.03–3.90) were also seen, but OS was not significantly different.ConclusionsThe rate of successful BCS is higher in the cCR group than in the non-cCR group, means cCR after NAC can encourage patients to receive BCS. The achievement of pCR after NAC in BCS patients was associated with a good prognosis in terms of LRFS and DRFS, but its value in DFS and OS requires further investigation.

Objectives The aim of the study is to evaluate the efficacy and prognosis of neoadjuvant chemotherapy (NAC) combined with breast-conserving surgery (BCS) in treating triple-negative breast cancer (TNBC) and analyze the influencing factors and predictors of the efficiency and prognosis of NAC. Methods A retrospective cohort study was conducted by dividing patients into two groups according to two different therapy methods. With BCS as the exposure factor, 46 cases were assigned to the exposed group and 80 cases to the nonexposed group. We compare the difference in operation-related indicators, postoperative complications, local recurrence rate, distant metastasis rate, and overall survival (OS) rate between the two groups. The factors affecting the efficiency and prognosis of NAC were analyzed by binary logistic regression, and the optimal cutoff value was determined by the area under the ROC curve (AUC). The survival curve was plotted, and the univariate log-rank test was performed to analyze the difference in OS between the two groups. The influencing factors of OS were analyzed by the Cox risk regression model. Results NAC + BCS resulted in significantly less intraoperative blood loss, lower incidence of postoperative complications, and shorter operative time and length of hospital stay than that in NAC (P < 0.05). There was no significant difference in local recurrence, distant metastasis, or OS between the two groups (P > 0.05). Multivariate analysis showed that the clinical stage I and Ki-67 high expression were independent protective factors of the efficacy of NAC. The high expression of Ki-67 and nondecline expression of Ki-67 were independent risk factors of prognosis. Ki-67 high expression was an independent risk factor of OS (P < 0.05). The ROC curve showed that the AUC of Ki-67 for NAC efficacy, prognosis, and OS were 0.706, 0.820, and 0.687, respectively, with optimal cutoff values of 25.5%, 29.0%, and 32.5%, respectively. Survival analysis showed that the OS of patients with NAC + BCS was 73.9% and NAC + MRM was 70.0% (P > 0.05). In the low expression subgroup of Ki-67, the OS of the two groups were 100.0% and 77.8%, respectively (P=0.060). In the high expression subgroup of Ki-67, the OS of the two groups were 53.8% and 63.6%, respectively (P=0.419). Conclusions NAC + BCS is a good method for treating TNBC, which has an obvious short-term effect and a good long-term prognosis. Clinical stage I and the high expression of Ki-67 are independent protective factors for the efficacy of NAC. The high expression of Ki-67 and nondecline expression of Ki-67 are independent risk factors of prognosis. Ki-67 is a potential predictor for the efficacy, prognosis, and OS of NAC in TNBC patients. The high expression of Ki-67 indicates better NAC efficacy, a poorer prognosis, and a lower OS.

77 Background: Total neoadjuvant therapy (TNT) improves overall survival (OS) while maintaining local recurrence-free survival (LRFS) in locally advanced rectal cancer (LARC). Real-world data are essential to refine patient selection and outcomes. Methods: Multicentre retrospective study of LARC patients treated with TNT in three Brazilian cancer centres. Outcomes: sphincter preservation and survival endpoints. Kaplan–Meier estimated survival; log-rank compared groups; Cox regression identified prognostic factors. Results: A total of 281 patients were analyzed (median age 58 [22–83], follow-up 31 [6–69 months]). Key baseline characteristics: T4 19%, N2 28%, extramural vascular invasion (EMVI) 15%, positive MRF (MRF+) 29%, lower rectum 64%, grade 3 tumors 5%, signet-ring 4%; treatment: IMRT 66%, 3D-CRT 34%, short-course radiotherapy (SCRT) 50%, long-course radiotherapy (LCRT) 50%; neoadjuvant chemotherapy regimens included CAPOX 61%, FOLFOX 35%, FOLFIRINOX 3%, and capecitabine monotherapy 1%. Overall, 212 (76%) underwent surgery and 65 (23%) were managed with watch-and-wait (WW). Pathological complete response (pCR) was achieved in 21%. Sphincter preservation was 78%. Absence of pCR (HR 3.14, 95% CI 1.32–7.47, p=0.009) and MRF+ (HR 2.14, 95% CI 1.21–3.77, p=0.009) predicted worse RFS; WW (HR 0.45, 95% CI 0.21–0.96, p=0.038) and mid- vs. lower-rectal tumors (HR 0.51, 95% CI 0.26–0.99, p=0.046) predicted improved RFS. Absence of pCR (HR 3.67, 95% CI 1.43–9.46, p=0.007) and MRF+ (HR 2.43, 95% CI 1.34–4.41, p=0.004) were associated with worse distant disease-free survival (DDFS). Grade 3 tumors and signet-ring histology were associated with worse LRFS. Three-year RFS, DDFS, LRFS, and OS were 74%, 75%, 93%, and 89%, respectively. No difference in LRFS or OS was observed between SCRT and LCRT (HR for OS 2.0, 95% CI 0.93–4.32, p=0.072). Radiotherapy technique (IMRT vs 3D-CRT) did not affect LRFS. Prognostic factors for worse OS included signet-ring histology, MRF+, EMVI, grade 3 tumors, and distal tumor location. Conclusions: TNT in Brazilian LARC patients achieved outcomes consistent with international series. pCR and MRF were key prognostic factors. No LRFS or OS difference was observed between SCRT and LCRT, supporting the adoption of different TNT strategies in clinical practice.

Background: Oncoplastic surgery (OPS) has emerged as a new approach for extending breast conserving surgery (BCS) possibilities, reducing mastectomy and re-excision rates, while avoiding breast deformities. OPS integrates plastic surgery techniques for immediate reshaping after wide excision for breast cancer. This techniques is emerging and our experience in Egypt has been gradually increasing. Our aim was to extend the applicability of OPS into more advanced tumours following neoadjuvant chemotherapy. Method: A prospective feasibility cohort study of OPS after neoadjuvant chemotherapy was carried at the national Cancer institute – Cairo University and included 40 patients. We aimed to look at long term oncologic safety and cosmetic outcomes. The primary outcome was the local recurrence rate. Secondary outcomes included survival and margins obtained as well as cosmetic outcomes. Survival analysis was performed with Kaplan-Meir curves. Cosmetic outcomes were assessed using a modified Breast Q questionnaire (EORTC 10801). Results: 40 patients were included in this study. All were diagnosed with locally advanced breast cancer between September 2012 and January 2015 at the National Cancer Institute – Cairo University. All were treated primarily with neoadjuvant chemotherapy (Anthracycline-based). The median age was 44.45 (Range 22- 65) years with median follow-up period of 42 (Range 24 – 60) months. 27.5% showed complete pathological response. 62.5% of patients had a level I OPS procedure, 10% had a level II procedure, and 27.5% had a volume replacement procedure with a Latissimus Dorsi flap. The median resection margins with level I, level II, and volume replacement were 10 mm,25 mm and 15 mm respectively. The difference in margins between level I and II was statistically significant (p = 0.028), so was the difference between the 3 types of procedures (p = 0.035). Three patients (7.5%) had local recurrence and required mastectomy; at 11, 13 and 16 months respectively. One of those (2.5%) developed distant bone metastasis. Cumulative disease-free survival (DFS) for the whole cohort was 90.2%. Overall survival (OS) was 100% as there was no mortality reported during the follow-up period. Cumulative disease-free survival for patients with level I surgery was 85.4% while for those with level II and volume replacement it was 100% with no statistically significant difference (p = 0.2) because of small number of events. The cumulative disease-free survival when the median resection margin obtained was less than 20 mm was 86.3%, whereas when the median margin was equal or more than 20 mm, it was 100%. This difference was not statistically significant (p = 0.2). The cosmetic outcomes ranged between excellent result (70%), very good (15%), good (10%) and poor results (5%) on a very simplified scale that was used for the purpose of the study. Discussion: Oncoplastic breast surgery didn't compromise oncologic safety in the patients included in the study. The local recurrence rate, the DFS and OS were all within acceptable ranges .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. Citation Format: Youssef M, Namour A, Youssef O, Morsi A. Oncoplastic breast surgery is oncologically safe in locally advanced breast cancer after neoadjuvant chemotherapy, an Egyptian experience [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-25.

Background The appropriate negative margin width following breast-conserving surgery (BCS) for both ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) has witnessed a shift towards de-escalation in international guidelines. However, there are limited nationwide data regarding margin assessment practice for BCS in China. This study aims to clarify the current real-world status of margin assessment from a single institution audit and secondarily to update the evidence on the association between margin width and local recurrence. Methods Eligible cases were derived from an extensive series of consecutive unselected patients with early invasive breast cancer who were treated with BCS at the Department of Breast Surgery in Shanghai Cancer Center Fudan University (FUSCC) between January 2015 and December 2017. Patient demographic and clinicopathological information as well as follow-up data were extracted from the hospital's electronic medical records. Pathological evaluation of negative margins was defined as no ink on tumor for IC in accordance with the SSO/ASTRO consensus guidelines released in 2014. Where applicable, margins were categorized as tumor on ink (involved), close margins (no tumor on ink but ≤1 mm), clear margins (1-2 mm), wide margins (2-5 mm), and wider margins (&amp;gt;5 mm). The positive margin rate (PMR), reoperation rate, and ipsilateral breast recurrence (IBR) rate were calculated according to different margin widths. Multivariable analyses of factors associated with re-excision were performed using binary logistic regression. Kaplan‒Meier survival curve analysis was performed for local recurrence-free survival (LRFS). Results A total of 2707 patients were enrolled in the current study, with a total PMR of 2.7%. The distribution of margin width revealed that wider margins (&amp;gt;5 mm) were optimized by most surgical oncologists (2092/2707, 77.3%) for BCS in our center. Additionally, the reoperation rates were 1.9% in the whole population, accounting for 48.3%, 7.5%, 4.2%, 0.8%, and 0.4% in each margin group. Specifically, among 247 patients with margins ≤2 mm, 41 (16.6%) received reoperation either by margin re-excision or mastectomy. Multivariable analyses identified that lobular histology, no selective additional resection and in situ pathology of involved/close margins are independent factors of re-excision recommendation. With a median follow-up of 54.3 months, the incidence of IBR was 1.7% in the whole cohort, representing for 5.2%, 4.2%, 2.8%, 1.9%, and 1.3% in each margin group, respectively. Kaplan‒Meier survival curve analysis showed a marginally significant difference in 5-year LRFS between groups with margins &amp;gt;2 mm and margins ≤2 mm (95.9% vs 97.8%, Table 1). Conclusions A wider margin width was preferably adopted in the routine practice of BCS. Our audit was aligned with previous evidence that a minimum clear margin of 2 mm is associated with a lower reoperation rate but favorable local control. Patients with margins no more than 2 mm were more likely to have re-excision in cases of lobular histology, no selective additional resection, and in situ pathology of involved/close margins. Ipsilateral breast recurrence models by margin status Citation Format: Feilin Qu, Cheng-Jia Shen, Wen-Tao Yang, Jun-Jie Li, Guangyu Liu, Zhi-Ming Shao. Current margin assessment practice for breast-conserving surgery in China: a single institution audit [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-22-09.

We investigated factors related to the type of surgery, i.e. mastectomy versus breast conserving surgery (BCS), in breast cancer (BC) patients with complete pathologic response in the breast (ypT0) after neoadjuvant therapy (NAT). A retrospective analysis from the EUSOMA database was performed using data from 55 certified centers across 14 European countries, including ypT0 BC patients (i.e., neither invasive nor in situ residuals), treated between 2017 and 2022. Variables analyzed included year of surgery, age, number and distribution of tumor focality, extent, clinical and pathological stages, and biologic subtype. Logistic regression was used to identify predictors of surgical choice. The Kaplan-Meier method was used for comparison of local recurrence-free survival (LRFS) between surgical groups. Of 1416 BC patients included, 67.5% underwent BCS and 32.5% mastectomy. At multivariable analysis, factors increasing the likelihood of mastectomy included: more recent year of surgery [odds ratio (OR) 2.61, 95% confidence interval (95%CI): 1.51-4.51,p=0.001], younger age (OR: 0.96, 95%CI: 0.95-0.97,p<0.001), multifocality (OR: 2.20, 95%CI: 1.61-3.00,p<0.001) and multicentricity (OR: 12.66, 95%CI: 6.82-23.49,p<0.001), advanced clinical tumor stage (OR: 14.54, 95%CI: 5.80-36.47,p<0.001), and baseline axillary nodal involvement (OR: 1.56, 95%CI: 1.12-2.17,p=0.009). Comparison between groups did not show a significant difference in LRFS (p=0.389). Many BC patients undergo mastectomy despite achieving complete response of primary tumor after NAT. Patients-related and tumor-related features, as well as having surgery in more recent years, seems to influence this choice. Our findings suggest the need for an optimized decision-making to spare unnecessary mastectomies.

Background: The benefit of adjuvant regional nodal irradiation including the chest wall after mastectomy (CWI+RNI) and with whole breast irradiation (WBI+RNI) after breast conserving surgery (BCS) is well established in pts with pathologically positive axillary nodes (pN+). Pts who present with axillary node involvement (cN+), receive neoadjuvant chemotherapy (NC), and are found to be pathologically node-negative at surgery (ypN0), have lower loco-regional recurrence (LRR) rates compared to those who remain pathologically node-positive (ypN+). This phase III, randomized trial aimed to evaluate whether CWI+RNI after mastectomy or addition of RNI to WBI after BCS significantly improves invasive breast cancer recurrence-free interval (IBC-RFI) in cN+ pts found to be ypN0 after NC. Methods: Eligible pts had clinical cT1-3, N1, M0 invasive breast cancer (biopsy-proven N+ by FNA/core needle bx), completed ≥8 wks of NC (and anti-HER2 therapy if HER2+), and were ypN0 after mastectomy or BCS and sentinel node biopsy (SLNB, ≥2 nodes), axillary lymph node dissection (ALND), or both. Pts were randomized to “No RNI” (i.e., observation after mastectomy or WBI after BCS) vs. “RNI” (i.e., CWI+RNI after mastectomy or WBI+RNI after BCS). Primary endpoint was IBC-RFI. Secondary endpoints reported here: LRR-free interval (LRRFI), distant recurrence-free interval (DRFI), disease-free survival (DFS), and overall survival (OS). Study was designed to have 80% power to detect 35% reduction in annual rate of IBC-RFI for an absolute risk reduction of 4.6% (5-yr cumulative rate). Per protocol, final analysis was to occur after 172 events or 10 yrs after study initiation.Here we report the time-driven analysis prespecified in the protocol. Results: From 9/13-12/20, 1,641 pts were enrolled; 1,556 pts were available for primary event analysis; median f/u time 59.5 mos (IQR 40.7-74.1). Pt/tumor characteristics were well balanced between groups. Median age 52 yrs (range 21-84); 31% non-white; 21% cT1, 60% cT2, 19% cT3; 23% triple-negative, 21% HR+/HER2-, 56% HER2+; 58% BCS; 55% SLNB, 45% ALND+/-SLNB; and 78% had breast pathologic complete response. At the time of the analysis, 109 IBC-RFI events (63% of the planned 172) were confirmed (“No RNI”: 59, “RNI”: 50). There was no statistically significant difference between groups for IBC-RFI (HR=0.88, 95%CI 0.60-1.29; p=0.51), 5-yr point estimates: 91.8% for “No RNI” and 92.7% for “RNI.” There were no statistically significant differences between the treatment groups for secondary endpoints. There were no study-related deaths and no unexpected toxicities.Grade 4 toxicity was rare (0.1% with “No RNI”, 0.5% with “RNI”); 6.5% of pts developed grade 3 toxicity in “No RNI” and 10% in “RNI” group. Most common grade 3 toxicity was radiation dermatitis (3.3% in “No RNI,” 5.7% in “RNI”). Conclusion: In pts who present with biopsy-proven axillary node involvement and convert their axillary nodes to ypN0 after NC, CWI+RNI after mastectomy, or WBI+RNI after BCS, did not significantly improve IBC-RFI, LRRFI, DRFI, DFS, or OS. These findings suggest that downstaging involved axillary nodes with NC can result in optimization of adjuvant radiotherapy without adversely affecting oncologic outcomes. Follow-up of pts for long-term outcomes continues. NCT01872975 *EPM and JW are co-first authors. Table 1 Citation Format: Eleftherios Mamounas, Hanna Bandos, Julia White, Thomas Julian, Atif Khan, Simona Shaitelman, Mylin Torres, Frank Vicini, Patricia Ganz, Susan McCloskey, Nilendu Gupta, X. Allen Li, Peter Lucas, Nadeem Abu-Rustum, Saumil Gandhi, Rahul Tendulkar, Robert Coleman, Keiichi Fujiwara, Samantha Seaward, William Irvin, Kristin Higgins, Robert Mutter, Jean-Francois Boileau, Andrew Muskovitz, Reshma Jagsi, Anna Weiss, Curran Walter Jr., Norman Wolmark. Loco-Regional Irradiation in Patients with Biopsy-proven Axillary Node Involvement at Presentation Who Become Pathologically Node-negative After Neoadjuvant Chemotherapy: Primary Outcomes of NRG Oncology/NSABP B-51/RTOG 1304 [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS02-07.

Resection margins and local recurrences in breast cancer: Comparison between conventional and oncoplastic breast conserving surgery

Impact of Sociodemographic Factors on Management of Breast Cancer: Results of QRRO Survey

In Regard to Moran et al

Primary adenoid cystic carcinomas (ACCs) of central trachea-bronchi system are rare and heterogeneous tumors. Definitive radiotherapy (RT) is the recommended treatment in surgically unresectable or incomplete resection or in the presence of severe comorbidities. To evaluate the clinical features and outcomes of patients with ACC of trachea-bronchi treated with radiotherapy. Retrospective medical records review was done in all patients with histologically confirmed ACC of trachea-bronchi between January 2010 and December 2019. Patient disease and treatment characteristics and toxicity data were analyzed. Overall survival (OS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were computed using Kaplan-Meier method (log-rank test). Nineteen patients (10 women and 9 men) were included in this analysis with median age of 40 years (range, 14-70). Of these patients, 63.2% (n = 12) presented in stage IV disease. Twelve and three patients received definitive (median dose 67.8 Gy) and adjuvant (median dose 50 Gy) RT, respectively. The median follow-up was 42.5 months (range, 4-120); 15 patients were alive and 4 were dead at that time. Local recurrence or progression was observed in 52.6% and distant metastasis found in 47.3% of patients. The 5-year OS, LRFS, and DMFS for all patients were 81.2%, 52.8%, and 39.6%, respectively. Baseline lymph node involvement showed significant impact on OS (56.3% vs 100%, p = 0.011). Among patients receiving definitive RT, patients with higher RT dose (⩾66 Gy) had significantly better survival outcomes (5-year LRFS: 75% vs 16.7%, p = 0.013). Definitive RT is an exemplary treatment for unresectable disease. Higher dose is recommended to improve long-term outcomes.

Objective To analyze the 10-year survival outcome and failure patterns for patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT), aiming to provide reference for optimized treatment for NPC. Methods Clinical data of 866 patients with NPC receiving IMRT from January 2001 to December 2008 were retrospectively analyzed. Survival analysis was performed using the Kaplan-Meier estimator. Univariate analysis was carried out by log-rank test and multivariate analysis was performed using Cox proportional hazards model. Results The median follow-up time was 132 months. The 10-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), progression-free survival (PFS) and disease specific survival (DSS) were 92.0%, 83.4%, 75.7% and 78.6%, respectively. A total of 210 patients died including 124 patients (59.0%) from distant metastasis, which was the primary cause of death, and 47(22.3%) from local regional recurrence. Independent negative factors of DSS included age>50 years (P=0.00), LDH≥245 IU/L (P=0.00), Hb 20 cm3(P=0.00). The 10-year LRFS, DMFS and DSS of stage Ⅱ NPC patients did not significantly differ after IMRT alone and chemoradiotherapy (P=0.83, 0.22, 0.23). For patients with stage Ⅲ NPC, the 10-year LRFS and DSS in the chemoradiotherapy arm were significantly higher than those in the IMRT alone (P=0.01, 0.01), whereas no statistical significance was observed in the DMFS between two groups (P=0.14). The overall survival of stage Ⅳa+ Ⅳb NPC patients is relatively poor. Conclusions IMRT can improve the long-term survival of NPC patients. Distant metastasis is the primary failure pattern. Patients with stage Ⅰ-Ⅱ NPC can obtain satisfactory survival outcomes after IMRT alone. The addition of chemotherapy can further enhance the LRFS and DSS of stage Ⅲ NPC patients. However, the optimal therapeutic strategy remains to be urgently investigated for stage Ⅳa+ Ⅳb NPC patients. Key words: Nasopharyngeal neoplasms/intensity-modulated radiotherapy; Failure pattern; Prognosis

Background Molecular subtypes of breast cancer are one of the key factors to predict clinical outcomes in women with breast cancer. Some specific subtypes like triple-negative breast cancer (TNBC) show more aggressive behaviors and worse clinical outcomes than luminal A subtype, thus there are conflicting data regarding optimum local surgical strategy for TNBC. We evaluate the clinical outcomes of women who underwent breast-conserving therapy (BCT) compared to those underwent mastectomy regarding to breast cancer subtypes using a large single center cohort. Methods A total of 5353 women who underwent BCT or mastectomy due to primary breast cancer from 1990 to 2010 were retrospectively reviewed. Cases with initial distant metastases or those with neoadjuvant chemotherapy were excluded. Clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) were analyzed using the Chi-square test, Kaplan-Meier survival analysis, and log-rank test. Cox proportional hazard models were used for multivariate analyses. In order to explore the role of BCT in TNBC, we performed sub-group analysis using patients with TNBC in the cohort. Results BCT was performed in 1866 cases and mastectomy in 3487 cases. The mastectomy group had higher T stage (T2-3: 53.5% vs. 26.5%, p&amp;lt;0.001), higher N stage (N2-3 17.1% vs. 5.1%, p&amp;lt;0.001), and more HER2 over-expression (11.6% vs. 8.3% p&amp;lt;0.001) than the BCT group had. The BCT group consisted of more Luminal A and TNBC subtypes than the mastectomy group. (Luminal A 56.2% vs 41.6%, TNBC 19.9% vs 12.7%, all p&amp;lt;0.001) The 5-year RFS rates of the BCT group in luminal A, B, and TNBC were better than those in the mastectomy group (Luminal A 93.7% vs 89.4%, p&amp;lt;0.001, Luminal B 94.9% vs. 86.3%, p=0.01, and TNBC 92.9% vs 79.8%, p&amp;lt;0.001). However, the 5-year RFS of HER2-enriched subtype was not significantly different according to the operation type (p=0.85). The BCT group in luminal A and TNBC showed better OS than the mastectomy group (Luminal A, p=0.002, TNBC, p&amp;lt;0.001), however, the difference of OS between the BCT and mastectomy groups in luminal B and HER2-enriched subtypes was not significant (p&amp;gt;0.05). In multivariate analyses, T and N stage, breast cancer subtypes, histologic grade, and the status of adjuvant chemotherapy were independent prognostic factors for RFS and OS (all p&amp;lt;0.05). However, The statistical significance of RFS and OS of local therapy, BCT vs. Mastectomy, according to breast cancer subtypes in the univariate analyses disappeared in multivariate analyses (HR for RFS=0.90, 95%CI=0.70-1.16, HR for OS=0.83, 95%CI=0.614-1.122). In the sub-group analysis, BCT showed comparable outcomes compared to mastectomy in patients with TNBC in multivariate analyses. (HR for RFS=0.89, 95%CI=0.38-2.06, HR for OS=1.007, 95%CI=0.987-1.028) Conclusions Clinical outcomes were not affected by surgical approaches regarding to breast cancer subtypes. BCT is an acceptable surgical approach regardless of breast cancer subtype, and even in selective patients with TNBC. Citation Format: Sanghwa Kim, Hyung Seok Park, Jee Ye Kim, Jegyu Ryu, Seho Park, Seung Il Kim. Implication of breast-conserving therapy in the subtype era of breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-13-09.

An increasing number of patients with breast cancer receiving neoadjuvant chemotherapy (NACT) undergo immediate breast reconstruction (IBR) with nipple-sparing mastectomy (NSM) or skin-sparing mastectomy (SSM) as surgical treatment. However, the oncologic efficacy and safety of this treatment sequencing strategy is unclear. To compare the long-term oncologic outcomes of IBR with NSM/SSM and conventional mastectomy (CM) alone for breast cancer in the NACT setting. A retrospective, propensity score-matched case-control study was conducted at Asan Medical Center, Seoul, Korea. A total of 1266 patients with breast cancer who underwent NACT followed by mastectomy with or without breast reconstruction between January 1, 2010, and November 30, 2016, were included. Data analysis was performed from July 1, 2019, to January 24, 2020. After propensity score matching, 323 patients who underwent IBR with NSM/SSM and 323 who underwent CM alone were selected for comparison of long-term oncologic outcomes. The 5-year local recurrence-free survival, disease-free survival, distant metastasis-free survival, and overall survival rates were calculated using the Kaplan-Meier method and compared using log-rank tests. Hazard ratios (HRs) and 95% CIs were estimated using the Cox proportional hazards regression model. After matching, the median follow-up periods were 67 (range, 17-125) months for the IBR group and 68 (range, 17-126) months for the CM-alone group. Median age of the women in the IBR group was 42 (range, 23-72) years; median age of those in the CM-alone group was 46 (range, 30-75) years. No significant differences were observed between the IBR and CM-alone groups in local recurrence (3.7% vs 3.4%; P = .83), regional recurrence (7.1% vs 5.3%; P = .33), or distant metastasis (17.3% vs 18.6%; P = .68) rates. There was also no significant difference between the IBR and CM-alone groups in 5-year local recurrence-free survival (95.6% vs 96.7%; HR, 1.124; 95% CI, 0.495-2.549; P = .78), disease-free survival (76.5% vs 79.9%; HR, 1.089; 95% CI, 0.790-1.500; P = .60), distant metastasis-free survival (82.5% vs 82.5%; HR, 0.941; 95% CI, 0.654-1.355; P = .74), or overall survival (92.0% vs 89.3%; HR, 0.847; 95% CI, 0.530-1.353; P = .49) rates. The long-term oncologic outcomes of IBR with NSM/SSM for breast cancer in this study appeared to be comparable to those of CM alone after NACT, suggesting the feasibility of IBR with NSM/SSM in the NACT setting.