Clinical Application of Multimodal Sentinel Lymph Node Mapping Method in Patients with Breast Cancer Undergoing Neoadjuvant Chemotherapy: An Interim Analysis.

BACKGROUND: After neoadjuvant chemotherapy (NAC), the SLN identification rate is lower and has a higher false-negative rate than that at upfront surgery. This clinical trial aimed to confirm the effectiveness of sentinel lymph node (SLN) surgery by determining the lymph node identification rate using multimodal SLN marker methods in patients with advanced breast cancer undergoing NAC. PATIENTS AND METHODS: This clinical study is a prospective single-center randomized controlled trial involving patients with breast cancer receiving NAC. Patients are randomized (1:1:1) into arm A that involves the use of radioisotope (RI) plus indocyanine green fluorescence (ICG-F); arm B, RI plus vital dye; and, arm C, ICG-F plus vital dye. A total of 348 patients are needed. An interim analysis was performed on 50% of the patients enrolled. The primary outcome of this trial was the SLN identification rate. RESULTS: Among the 164 total patients (median age 51 years), T2 and N1 were the most common clinical stages. The identification rate of SLN was 95% in arm A, 92% in arm B, and 79% in arm C. To assess superior efficacy, the one-sided endpoint was set at α < 0.0056. Arms A and C showed a difference of 0.1597 in the detection rate (p = 0.0055). CONCLUSIONS: The use of ICG-F plus vital dye for SLNB was the least effective. The results show that the choice of tracer should be radioisotope in combination with one of the other tracers to have the highest SLN identification rate when SLNB cannot be implemented conventionally due to the circumstances of each institution.

Surveillance for Distant Metastasis in Breast Cancer Patients Who Underwent Contemporary Management: A Report from the Korean Breast Cancer Society Survivor Research Group.

BACKGROUND: Current guidelines recommend against the use of routine imaging tests to detect distant metastasis in asymptomatic breast cancer patients. However, recent advancements in effective therapeutics and diagnostic accuracy have raised the need to reassess the clinical efficacy of intensive metastasis surveillance. We report the results of a multicenter retrospective study to investigate the association between intensive imaging studies and survival outcomes. PATIENTS AND METHODS: We retrospectively reviewed the data of 4130 patients who underwent surgery from 11 hospitals in Korea between January 2010 and December 2011. Patients were divided into two groups on the basis of the intensity of metastasis imaging studies during their disease-free period. The types and intervals of the imaging studies were based on each physician's decisions. RESULTS: High-intensive screening showed a shorter distant metastasis-free survival [p < 0.001, hazard ratio (HR) 1.62; 95% confidence interval (CI) 1.29-2.04], especially for patients in whom bone or lung was the first site of metastasis. With a median follow-up period of 110.0 months, the 5-year breast cancer-specific survival (BCSS) rate was 96.5%. The high-intensity screening group showed significantly poorer BCSS compared with the low-intensity screening group (p < 0.001, HR 3.13; 95% CI 2.32-4.21). However, both multivariable analysis and propensity score matching analysis showed no significant association between the screening intensity and BCSS. CONCLUSIONS: Frequent imaging studies to detect distant metastasis were associated with earlier detection of distant metastasis, especially for lung and bone metastasis. However, intensive surveillance showed no apparent association with BCSS despite the use of currently available treatments.

Analysis of the tumor characteristics in young age breast cancer patients using collaborative stage data of the Korea Central Cancer Registry.

PURPOSE: This study aimed to evaluate tumor characteristics in young age (20-39 years old) breast cancer (YABC) patients in Korea. MATERIALS AND METHODS: We identified 10,897 breast cancer patients from 2010 to 2015. The data were collected through 10% systematic sampling of the Korea National Cancer Incidence Database (KNCI DB). Tumor size, lymph node status, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status were collected according to the Collaborative Stage version 2 (CSv2) Data Collection System. RESULTS: Of the 10,897 patients, 1245 (11.4%) were YABC patients. They were found to have larger tumors (T2: 41.6% in 20-39 age group vs 36.4% in 40-49 age group vs 36.5% in 50-59 age group vs 38.4% in ≥ 60 age group; T3: 10.1% vs 7.3% vs 6.5% vs 6.2%, P < .0001), greater rates of lymph node involvement (41.2% vs 32.7% vs 35.7% vs 32.5%, P < .0001), higher tumor grade (High grade: 26.8% vs 19.4% vs 23.5% vs 22.1%, P < .0001), and a larger proportion of triple-negative subtype (18.2% vs 11.0% vs 12.2% vs 13.5%, P < .0001). Compared to the 40-49 age group, breast cancer-related survival (BCRS) rates were worse (91.74% vs 95.04%, P < .0001), and the characteristics of YABC patients were associated with higher risk of death from breast cancer. CONCLUSION: YABC patients have more aggressive tumor characteristics and worse survival rates. Therefore, we need to identify high-risk groups among YABC patients and support active surveillance in them. These findings from a national cohort provide important information for establishing a national cancer care strategy to manage YABC patients.

Optimal treatment of breast cancer in women older than 75 years: a Korea Breast Cancer Registry analysis.

PURPOSE: The aim of this study was to investigate the therapeutic efficacy of adjuvant modalities for elderly Asian breast cancer patients using population-based data from the Korean Breast Cancer Registry database. METHODS: We identified 53,582 patients who underwent curative surgery between January 2005 and December 2010. The primary end point was the comparison of overall survival between the administration or omission of adjuvant treatment modalities, including endocrine treatment, radiation therapy, and chemotherapy, in the elderly group (older than 75 years) compared with the control group (younger than 75 years). RESULTS: Of the 53,582 patients analyzed, the total number of elderly patients was 901 (1.7%), and the number of control patients was 52,681 (98.3%). Although elderly patients were found to have larger tumor sizes (p = 0.024) and higher pathological stages (p < 0.001) than the control group, elderly patients were less likely to undergo adjuvant treatment compared to the control group. However, use of endocrine treatment in elderly patients with HR-positive breast cancer is associated with improved overall survival (OS) (adjusted OR 0.417; 95% confidence interval [CI] 0.240-0.726; p = 0.002). Furthermore, chemotherapy was associated with a significant improvement in OS in patients with stage II and III breast cancer (adjusted OR 0.657; 95% CI 0.462-0.934; p = 0.019). CONCLUSION: Endocrine treatment and chemotherapy for elderly patients are associated with improved OS. Therefore, personalized decision-making based on the potential survival benefit of adjuvant treatment modalities should be made with the careful counseling of all elderly patients with breast cancer.

Retrospectively validating the results of the ACOSOG Z0011 trial in a large Asian Z0011-eligible cohort.

PURPOSE: The Z0011 trial demonstrated that axillary dissection (ALND) could be omitted during breast-conserving therapy for cT1-2N0 breast cancers with 1-2 metastatic SLNs. However, that result has not been validated in a larger cohort and the significance of the small number of SLNs remains unclear. This study aimed to validate the Z0011 results within an Asian Z0011-eligible cohort and determine whether the number of sentinel lymph nodes (SLNs) influenced the Z0011-based outcomes. METHODS: Data from Asian patients who fulfilled the Z0011 criteria were collected from five hospitals. Disease recurrence (DR) was compared between patients who underwent ALND or SLN dissection (SLND) alone. Propensity-score matching was performed to reduce the effects of potential selection biases. RESULTS: During 2010-2016, 1750 Asian patients had 1-2 SLN metastases and fulfilled the Z0011 criteria. These patients included 707 cases treated using SLND alone (40%) and 967 patients with ≤ 2 SLNs (55%). Ninety-five patients (5.4%) experienced DR at a median interval of 50 months, although the rates of DR were similar in the ALND and SLND groups. The adjusted hazard ratios for DR after ALND omission were 0.95 (95% CI 0.55-1.64) among the entire cohort and 0.83 (95% CI 0.34-2.03) among patients with ≤ 2 SLNs. CONCLUSIONS: In this Asian Z0011-eligible cohort, ALND omission did not increase risk of DR, even among patients with ≤ 2 SLNs. Therefore, the Z0011 strategy might be safely applied in Asia, and a small number of SLNs did not significantly influence this strategy.

The Sentinel Lymph Node Biopsy Using Indocyanine Green Fluorescence Plus Radioisotope Method Compared With the Radioisotope-Only Method for Breast Cancer Patients After Neoadjuvant Chemotherapy: A Prospective, Randomized, Open-Label, Single-Center Phase 2 Trial.

BACKGROUND: This study aimed to compare the sentinel lymph node (SLN) identification rates for breast cancer patients after neoadjuvant chemotherapy (NAC) between the dual method (DM) of indocyanine green fluorescence (ICG-F) plus a radioisotope (RI) and RI alone. METHODS: This randomized study enrolled 130 patients who received NAC for breast cancer and 122 patients who received SLN biopsy (SLNB) using either DM (n = 58) or RI only (n = 64). The study compared the identification rate, number of SLNs, and detection time of SLNB. RESULTS: Among the 122 patients, 113 (92.6%) were clinically node-positive before NAC. The SLN identification rate was 98.3% in the DM group and 93.8% in the RI group (p = 0.14). The DM group and the RI group were similar in the average number of SLNs (2.2 ± 1.13 vs. 1.9 ± 1.33; p = 0.26) and the time to detection of the first SLN (8.7 ± 4.98 vs. 8.3 ± 4.31 min; p = 0.30). In the DM group, transcutaneous lymphatic drainage was visualized by fluorescence imaging for 65.5% (38 of 58) of the patients. The SLN identification rate was 94.7% using ICG-F and 93% using RI (p = 0.79). During and after the operation, no complications, including allergic reactions or skin necrosis, occurred. CONCLUSIONS: This study is the first randomized trial to use ICG-F for SLNB in breast cancer patients after NAC. The DM including ICG-F could be a feasible and safe method for SLNB in initially node-positive breast cancer patients with NAC.

Use of adjuvant chemotherapy in hormone receptor-positive breast cancer patients with or without the 21-gene expression assay.

PURPOSE: We assessed the use of chemotherapy in breast cancer patients to investigate the factors that changed trends in chemotherapy following the adoption of the 21-gene expression assay in tumor genomic profiling. METHODS: Our study used 2033 patients from the National Cancer Center in Korea diagnosed with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (tumor size of 0.5 cm or larger and 0-3 node metastases) from 2010 to 2015. We analyzed use of the 21-gene expression assay, changes in frequency of adjuvant chemotherapy use, and clinicopathological factors related to adjuvant chemotherapy to assess the impact of the 21-gene expression assay. RESULTS: Adjuvant chemotherapy use declined from 33.33% (2011) to 13.59% (2015) [relative risk (RR), 0.71; 95% CI 0.56-0.89; ptrend = 0.004] in patients with 21-gene expression assay data. Among patients without assay data, adjuvant chemotherapy use decreased from 76.79 to 40.17% between 2010 and 2015 (RR 0.87; 95% CI 0.84-0.91; ptrend < 0.001), especially for patients with node-negative/micrometastasis (RR 0.85; 95% CI 0.81-0.89; ptrend < 0.001). The frequency of adjuvant chemotherapy was significantly decreased after introduction of the 21-gene expression assay (p < 0.001). Tumor size (p < 0.001), progesterone receptor (PgR) status (p = 0.001), and proliferation index (Ki-67) levels (p < 0.001) were important factors for chemotherapy decision-making in node-negative/micrometastasis patients who did not undergo the assay. CONCLUSIONS: For HR-positive, HER2-negative breast cancer patients with 0-1 node metastases, chemotherapy use declined significantly after the adoption of the 21-gene assay. PgR status and Ki-67 were useful for chemotherapy decision-making in cases without the 21-gene assay.

Clinical Features of Li-Fraumeni Syndrome in Korea.

PURPOSE: Li-Fraumeni syndrome (LFS) is a hereditary disorder caused by germline mutation in TP53. Owing to the rarity of LFS, data on its clinical features are limited. This study aimed to evaluate the clinical characteristics and prognosis of Korean patients with LFS. MATERIALS AND METHODS: Patients who underwent genetic counseling and confirmed with germline TP53 mutation in the National Cancer Center in Korea between 2011 and 2022 were retrospectively reviewed. Data on family history with pedigree, types of mutation, clinical features, and prognosis were collected. RESULTS: Fourteen patients with LFS were included in this study. The median age at diagnosis of the first tumor was 32 years. Missense and nonsense mutations were observed in 13 and one patients, respectively. The repeated mutations were p.Arg273His, p.Ala138Val, and pPro190Leu. The sister with breast cancer harbored the same mutation of p.Ala138Val. Seven patients had multiple primary cancers. Breast cancer was most frequently observed, and other types of tumor included sarcoma, thyroid cancer, pancreatic cancer, brain tumor, adrenocortical carcinoma, ovarian cancer, endometrial cancer, colon cancer, vaginal cancer, skin cancer, and leukemia. The median follow-up period was 51.5 months. Two and four patients showed local recurrence and distant metastasis, respectively. Two patients died of leukemia and pancreatic cancer 3 and 23 months after diagnosis, respectively. CONCLUSION: This study provides information on different characteristics of patients with LFS, including types of mutation, types of cancer, and prognostic outcomes. For more appropriate management of these patients, proper genetic screening and multidisciplinary discussion are required.

Questionnaire study of application about sentinel lymph node biopsy surgery in locally advanced breast cancer patients who received neoadjuvant chemotherapy.

Background: Nodal staging from sentinel lymph node (SLN) biopsy has become the standard procedure for early-stage breast cancer patients. SLN biopsy implementation after chemotherapy has previously been evaluated. This questionnaire study aimed to investigate the current trend of SLN biopsy after neoadjuvant chemotherapy (NAC) for locally advanced breast cancer. Methods and materials: We conducted a web-based survey among breast surgeons who are members of the Korean Breast Cancer Society. The survey comprised 14 questions about axillary surgery after NAC. Results: Of 135 respondents, 48.1% used a combined method of dye and radioactive isotope (RI). In the absence of SLN metastasis, 67.7% would perform only SLN biopsy, while 3% would perform ALN dissection. In case of SLN metastasis, the proportions of surgeons who would proceed with ALN dissection were 60.2% and 67.2% for less than two and more than three positive SLNs, respectively. Conclusion: The present study confirmed the increasing tendency to adopt SLN biopsy for axillary staging in patients who achieved complete response with initial nodal metastasis. It could be expected that the mapping methods for patients receiving NAC have become diverse, including RI, vital dye, and indocyanine green fluorescence. The implementation of SLN biopsy after NAC will grow in the coming years due to an increasing demand of minimally invasive surgery.

Androgen Receptor as a Predictive Marker for Pathologic Complete Response in Hormone Receptor-Positive and HER-2-Negative Breast Cancer with Neoadjuvant Chemotherapy.

PURPOSE: This study investigated pathological complete response (pCR) according to androgen receptor (AR) in breast cancer patients undergoing neoadjuvant chemotherapy and estimated the relationship between AR expression and clinicopathological factors. Materials and Methods: We identified 624 breast cancer patients who underwent surgery after neoadjuvant chemotherapy at the National Cancer Center in Goyang, Korea from April 2016 to October 2019. We retrospectively collected the clinicopathologic information and AR expression results and analyzed the data according to cancer stage, hormonal receptor (HR) status, human epidermal growth factor receptor 2 (HER2) status, tumor subtype, and pCR. RESULTS: Among the 624 breast cancer patients, 529 (84.8%) were AR-positive (AR+) patients and 95 (15.2%) were AR-negative (AR-) patients. AR+ patients showed more estrogen receptor (ER) positivity, progesterone receptor (PR) positivity, HER2-positivity, and HR-positive and HER2-negative (HR+/HER2-) subtype. The rate of pCR was 31.4% (196/624). AR- patients had a significantly higher rate of pCR than AR+ patients (AR- 43.2% vs. AR+ 29.3%, p=0.007). The tumor factors associated with pCR were early stage, histologic grade 3, ER-negative, PR-negative, AR-negative, HER2-positive, and high Ki-67 values. In univariable analysis, AR+ significantly decreased the state of pCR (odds ratio, 0.546; 95% confidence interval, 0.349 to 0.853; p=0.008). According to tumor subtype, AR- tumor showed higher pCR rate in HR+/HER2- subtype (AR- 28.6% vs. AR+ 7.3%, p=0.022). CONCLUSION: AR expression is predominant in the HR+/HER2- subtype. AR- is significantly associated with the pCR rate in breast cancer patients, especially within HR+/HER2- subtype. When determining neoadjuvant chemotherapy for the HR+/HER2- subtype, AR expression can be considered as a pCR predictive marker.

Progranulin and Breast Cancer Mortality: 13-Year Follow-Up of a Cohort Study.

Background: We have reported that serum progranulin (PGRN) levels are clinically significant in predicting recurrence in patients with HR-positive breast cancer. The aim of the present study was to examine whether PGRN levels might be associated with breast cancer mortality. Methods: This was a cohort study of 695 newly diagnosed breast cancer patients who underwent curative surgery between 2001 and 2004. The relationship between breast cancer mortality and pre-operative serum PGRN levels in these patients with a median follow-up of 12.7 years was evaluated until May 2020. Results: A total of 118 (17%) deaths were identified in the cohort. According to the HR status, (10, 15, and 20)-year overall survival (OS) rates were (91.4, 81.1, and 75.9) % for HR-positive patients, and (76.5, 74.2, and 69.8) % for HR-negative patients, respectively (p = 0.003). Higher levels of PGRN were significantly associated with poor OS in the HR-positive group (p for trend = 0.001). In particular, hazard ratios for PGRN quartiles suggested a dose-response relationship, with the highest quartile having the worst OS in the HR-positive group (highest vs lowest: 15-year OS, (68.3 vs 90.0) %; 20-year OS, (62.3 vs 84.8) %, even after adjusting for age, tumor stage, and metabolic confounders. Conclusion: Pre-operative serum PGRN levels had clinical significance for predicting cancer mortality in breast cancer patients independent of tumor stage and metabolic parameters, especially in HR-positive tumors.

Clinicopathological Factors Associated with Oncotype DX Risk Group in Patients with ER+/HER2- Breast Cancer.

Oncotype DX (ODX), a 21-gene assay, predicts the recurrence risk in early breast cancer; however, it has high costs and long testing times. We aimed to identify clinicopathological factors that can predict the ODX risk group and serve as alternatives to the ODX test. This retrospective study included 547 estrogen receptor-positive, human epidermal growth factor receptor 2-negative, and lymph node-negative breast cancer patients who underwent ODX testing. Based on the recurrence scores, three ODX risk categories (low: 0-15, intermediate: 16-25, and high: 26-100) were established in patients aged ≤50 years (n = 379), whereas two ODX risk categories (low: 0-25 and high: 26-100) were established in patients aged >50 years (n = 168). Factors selected for analysis included body mass index, menopausal status, type of surgery, and pathological and immunohistochemical features. The ODX risk groups showed significant association with histologic grade (p = 0.0002), progesterone receptor expression (p < 0.0001), Ki-67 (p < 0.0001), and p53 expression (p = 0.023) in patients aged ≤50 years. In patients aged >50 years, tumor size (p = 0.022), Ki-67 (p = 0.001), and p53 expression (p = 0.001) were significantly associated with the risk group. Certain clinicopathological factors can predict the ODX risk group and enable decision-making on adjuvant chemotherapy; these factors differ according to age.

Multidisciplinary Shared Decision Making for Fertility Preservation in Young Women With Breast Cancer.

PURPOSE: Fertility preservation (FP) is an important issue for young survivors of breast cancer. Although international guidelines recommend pre-treatment fertility counseling for women with breast cancer, there is no standardized protocol or referral system for FP in South Korea. There are also barriers to discussing FP that make patient-centered decision making difficult. This study aimed to develop a shared decision making program for FP and compare the rates of FP procedures between the usual care and shared decision making groups. We hypothesized that multidisciplinary shared decision making for FP would increase the rate of FP procedures and patient satisfaction. METHODS: The multidisciplinary shared decision making for FP in young women with breast cancer (MYBC) is a multicenter, clustered, stepped-wedge, randomized trial. A total of 1100 patients with breast cancer, aged 19-40 years, from nine hospitals in South Korea, will be enrolled. They will be randomized at the institutional level and assigned to usual care and shared decision making groups. Four institutions, each of which can recruit more than 200 patients, will each become a cluster, whereas five institutions, each of which can recruit more than 50 patients, will become one cluster, for a total of five clusters. The shared decision making groups will receive multidisciplinary programs for FP developed by the investigator. The primary outcome is the rate of FP procedures; secondary outcomes include fertility results, satisfaction, and quality of life. Outcomes will be measured at enrollment, treatment initiation, and the 1-, 3-, and 5-year follow-ups after starting breast cancer treatment. DISCUSSION: A multidisciplinary shared decision making program for FP is expected to increase fertility rates and satisfaction among young patients with breast cancer. This study will provide the evidence to implement a multidisciplinary system for patients with breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05139641. Registered on December 1, 2021.

Differences in Willingness to Undergo BRCA1/2 Testing and Risk Reducing Surgery among the General Public, Cancer Patients, and Healthcare Professionals: A Large Population-Based Survey.

We aimed to understand the decision-making process related to the willingness to undergo BRCA1/2 genetic testing, risk-reducing salpingo-oophorectomy (RRSO), or risk-reducing mastectomy (RRM) among the general public, cancer patients, and healthcare professionals in South Korea. In total, 3444 individuals (1496 from the general public, 1500 cancer patients, 108 clinicians, and 340 researchers) completed a survey addressing genetic testing and related risk management options in a hypothetical scenario. Differences in intent and associated factors for undergoing the above procedures or sharing test results were analyzed. Overall, 67% of participants were willing to undergo BRCA1/2 testing, with proportions of the general public (58%), cancer patients (70%), clinicians (88%), and researchers (90%). The willingness to undergo RRSO was highest among clinicians (58%), followed by among patients (38%), the general public (33%), and researchers (32%) (p < 0.001). Gender, age, education level, and household income were associated with willingness to undergo genetic testing, RRM, and RRSO (p < 0.05). The intent for undergo genetic testing, RRM, and RRSO were affected by many factors. Finally, 69% of the general public intended to share information with family, while this percentage was 92%, 91%, and 94% for patients, clinicians, and researchers, respectively (p < 0.05). These results highlight the requirement for developing targeted educational materials and counseling strategies for facilitating informed decision making.

Surgical outcomes of localization using indocyanine green fluorescence in breast conserving surgery: a prospective study.

We investigated localization and safe resection margins for breast cancer patients undergoing breast conserving surgery (BCS) using ultrasound-guided indocyanine green fluorescence (ICG-F) marking. From April 2016 to March 2019, we prospectively enrolled 114 patients who underwent BCS using US-guided ICG-F marking and we compared these results with 300 patients who underwent BCS using US-guided skin marking from January 2012 to December 2016. Clinical features, identification rates, status of resection margins, and re-operation rates were analyzed. The ICG-F identification rate was 100% (114/114). The mean approach time for resection of the lesion ICG-F using group was about 13 min. The positive rate of frozen resection margins was 10.5% using ICG-F and 25.0% using sono-guided skin marking (p < 0.01). The rate of additional intraoperative resection was significantly lower in the ICG-F marking group compared to that in the sono-guided skin marking group (8.8% vs. 23.3%, p < 0.01). The rate of final positive resection margins was 3.5% in the ICG-F using group and 14.7% in the sono-guided skin marking group (p < 0.01). The rate of re-operation was 4.4% in the ICG-F using group and 4% in the sono-guided group (p = 0.79). At follow-up after the operation using ICG-F, no complications occurred. Using ICG-F during BCS could be a safe, sophisticated method for localization.

Clinical Effectiveness of Hypofractionated Proton Beam Therapy for Liver Metastasis From Breast Cancer.

BACKGROUND: Few studies of proton beam therapy (PBT) for patients with liver metastasis from breast cancer (LMBC) are available to date. The aim of the present study was to evaluate the clinical effectiveness of PBT for patients with LMBC. MATERIAL AND METHODS: Seventeen patients with LMBC treated with PBT were included in this study. The median prescribed dose of PBT was 66 GyE (range, 60-80) in 10 fractions, 5 times a week. In patients with LMBC receiving PBT, freedom from local progression (FFLP), progression-free survival (PFS), and overall survival (OS) rates were assessed. RESULTS: The median follow-up time was 34.2 months (range, 11.5-56.1). The median FFLP time was not yet reached, and the 3-year FFLP rates were 94.1% (95% confidence interval [CI], 82.9-105.3). The median times of PFS and OS were 7.9 months (95% CI, 5.3-10.5) and 39.3 months (95% CI, 33.2-51.9), respectively, and the 3-year PFS and OS rates were 19.6% (95% CI, -1.8-41.0) and 71.7% (95% CI, 46.8-96.6), respectively. Grade 3 or higher adverse events were not observed. CONCLUSION: PBT for patients with LMBC showed promising FFLP and OS with safe toxicity profiles. These findings suggest that PBT can be considered a local treatment option in patients with LMBC.

Criteria for identifying residual tumours after neoadjuvant chemotherapy of breast cancers: a magnetic resonance imaging study.

We investigated magnetic resonance imaging (MRI) criteria identifying residual tumours in patients with triple-negative and human epidermal growth factor receptor type 2-positive (HER2+) breast cancer following neoadjuvant chemotherapy. Retrospectively, 290 patients were included who had undergone neoadjuvant chemotherapy and definitive surgery. Clinicopathological features, as well as lesion size and lesion-to-background parenchymal signal enhancement ratio (SER) in early- and late-phase MRIs, were analysed. Receiver operating characteristic (ROC) analyses evaluated diagnostic performances. Maximal MRI values showing over 90% sensitivity and negative predictive value (NPV) were set as cut-off points. Identified MRI criteria were prospectively applied to 13 patients with hormone receptor-negative (HR-) tumours. The lesion size in HR-HER2-tumours had the highest area under the ROC curve value (0.92), whereas this parameter in HR + HER2 + tumours was generally low (≤ 0.75). For HR-tumours, both sensitivity and NPV exceeded the 90% threshold for early size > 0.2 cm (HR-HER2-) or > 0.1 cm (HR-HER2 +), late size > 0.4 cm, and early SER > 1.3. In the prospective pilot cohort, the criteria size and early SER did not find false negative cases, but one case was false negative with late SER. Distinguishing residual tumours based on MRI is feasible in selected triple-negative and HER2 + breast cancer patients.

ELOVL2: a novel tumor suppressor attenuating tamoxifen resistance in breast cancer.

Epigenetic events have successfully explained the cause of various cancer types, but little is known about tamoxifen resistance (TamR) that induces cancer recurrence. In this study, via genome-wide methylation analysis in MCF-7/TamR cells we show that elongation of very-long chain fatty acid protein 2 (ELOVL2) was hypermethylated and downregulated in the samples from TamR breast cancer patients (n = 28) compared with those from Tam-sensitive (TamS) patients (n = 33) (P < 0.001). Strikingly, in addition to having tumor suppressor activity, ELOVL2 was shown to recover Tam sensitivity up to 70% in the MCF-7/TamR cells and in a xenograft mouse model. A group of genes in the AKT and ERa signaling pathways, e.g., THEM4, which play crucial roles in drug resistance, were found to be regulated by ELOVL2. This study implies that the deregulation of a gene in fatty acid metabolism can lead to drug resistance, giving insight into the development of a new therapeutic strategy for drug-resistant breast cancer.