Impact of 18F-FES PET/CT on Clinical Decisions in the Management of Recurrent or Metastatic Breast Cancer.

The clinical impact of 16α-18F-fluoro-17ß-estradiol (18F-FES) PET/CT on patient management has not been well investigated. The aim of this study was to assess the clinical impact of 18F-FES PET/CT on the management of patients with recurrent or metastatic breast cancer. Methods: Study subjects were identified retrospectively from a database of a prospective trial for postmarketing surveillance of 18F-FES between 2021 and 2023. Patients who were suspected or known to have recurrent or metastatic estrogen receptor-positive breast cancer based on a routine standard workup were included. Planned management before and actual management after 18F-FES PET/CT were assessed by 2 experienced medical oncologists via medical chart review. A 5-point questionnaire was provided to evaluate the value of 18F-FES PET/CT for management planning. The rate of intention-to-treat and interdisciplinary changes, and the impact of 18F-FES PET/CT according to PET/CT result or clinical indication, were examined. Results: Of the 344 included patients, 120 (35%) experienced a change in management after 18F-FES PET/CT. In 139 (40%) patients,18F-FES PET/CT supported the existing management decision without a change in management. Intention-to-treat and interdisciplinary changes accounted for 64% (77/120) and 68% (82/120) of all changes, respectively. A higher rate of change was observed when lesions were 18F-FES-negative (44% [36/81]) than 18F-FES-positive (30% [51/172]) or mixed 18F-FES-positive/negative (36% [33/91]). Regarding clinical indications, the highest rate of change was shown when evaluating the origins of metastasis of double primary cancers (64% [9/14]). Conclusion: 18F-FES PET/CT modified the management of recurrent or metastatic breast cancer, serving as an impactful imaging modality in clinical practice.

Long-term outcomes and risk profile of cT3N0 breast cancer treated with neoadjuvant chemotherapy and curative surgery.

INTRODUCTION: We evaluated the treatment outcomes and failure patterns in cT3N0 breast cancer patients classified for rigorous pretreatment evaluation and treated with neoadjuvant chemotherapy (NAC) and curative surgery. METHODS: We reviewed the records of 87 cT3N0 breast cancer patients who received NAC and curative surgery between 2000 and 2015. The clinical high-risk group was defined as having two or more risk factors: age < 40, histologic grade 3, lymphovascular invasion, hormone receptor negativity, and Ki-67 labeling index >20%. RESULTS: Of the patients, 84 (96.6%) and 79 (90.8%) were initially evaluated using magnetic resonance imaging and positron emission tomography/computed tomography. Most patients received anthracycline based NAC regimen (n = 69, 79.3%) and modified radical mastectomy (n = 61, 70.1%). During a 91.5-month median follow-up, ten patients experienced distant metastasis (DM) only, two had isolated local recurrence, one had local recurrence and DM, and another had local recurrence, regional recurrence, and DM. The 5-year rates of locoregional recurrence, DM, any recurrence (AR), and overall survival (OS) were 1.2%, 11.6%, 11.6%, and 90.8%, respectively. The risk group was an independent prognostic factor of recurrence, and the high-risk group had worse rates of DM (19.2% vs. 0%, P = 0.009), AR (19.2% vs. 0%, P = 0.016) and OS (82.8% vs. 100%, P = 0.001). CONCLUSION: Patients with cT3N0 breast cancer classified for rigorous pretreatment evaluation and treated with NAC and radical surgery had favourable oncological outcomes. A clinical risk group based on clinical and immunohistochemical risk factors was an excellent predictor of survival and recurrence.

Longitudinal dynamics of circulating tumor DNA for treatment monitoring in patients with breast cancer recurrence.

The prevalence and dynamics of circulating tumor DNA (ctDNA) in patients with breast cancer recurrence or de novo metastatic cancer were examined in a retrospective analysis of a prospective observational cohort. Twenty-three recurrent/metastatic breast cancer cases (8 locoregional, 15 distant metastasis) were enrolled, and sequential plasma samples were obtained. Anchor mutations were selected from the target sequencing of each patient's primary and/or metastatic tumor. An in-house developed assay (UHS assay) was employed for a tumor-informed ctDNA assay during treatment and follow-up. A median of three (range 1-5) anchor mutations per case were applied for ctDNA detection. ctDNA was detected in 14 (63.6%, 14/22) cases at the time of enrollment and 18 (78.5%, 18/23) cases during follow-up. More anchor mutations and higher tumor burden were significantly related to higher ctDNA positive rates (p-value 0.036, 0.043, respectively). The mean enriched variant allele frequency (eVAF) at each time point was significantly higher for stable or progressive disease responses (ANOVA test p-value < 0.001). Eight patients showed an increase in their ctDNA eVAF prior to clinical progression with a mean lead time of 6.2 months (range 1.5-11 months). ctDNA dynamics measured using personalized assay reflected the clinical course of breast cancer recurrence.

Evaluation of safety and operative time in tumescent-free robotic nipple-sparing mastectomy: a retrospective single-center cohort study.

Purpose: Tumescent in nipple-sparing mastectomy (NSM) has been reported to increase the risk of necrosis by impairing blood flow to the skin flap and nipple-areolar complex. At our institution, we introduced a tumescent-free robotic NSM using the da Vinci single-port system (Intuitive Surgical, Inc.). Methods: We conducted a retrospective analysis of patients who underwent tumescent-free robotic NSM between October 2020 and March 2023 at Asan Medical Center (Seoul, Korea). Clinicopathological characteristics, adverse events, and operative time were evaluated. Results: During the study period, 118 patients underwent tumescent-free robotic NSM. Thirty-one patients (26.3%) experienced an adverse event. Five patients (4.2%) were classified as grade III based on the Clavien-Dindo classification and required surgery. The mean total operative time was 467 minutes for autologous tissue reconstruction (n = 49) and 252 minutes for implants (n = 69). No correlation was found between the cumulative number of surgical cases and the breast operative time (P = 0.30, 0.52, 0.59 for surgeons A, B, C) for the 3 surgeons. However, a significant linear relationship (P < 0.001) was observed, with the operative time increasing by 13 minutes for every 100-g increase in specimen weight. Conclusion: Tumescent-free robotic NSM is a safe procedure with a feasible operative time and few adverse events.

Survival pattern in male breast cancer: distinct from female breast cancer.

Introduction: Male breast cancer (MBC) is a rare condition, and recent research has underscored notable distinctions between MBC and breast cancer in women. This study aimed to assess and contrast the long-term survival outcomes and disease patterns of MBC patients with those of their female counterparts. Methods: We analyzed data from 113,845 patients diagnosed with breast cancer who had undergone curative surgery from the Korean Breast Cancer Registry (KBCR) between January 1990 and August 2014 in Seoul, Korea. The five-year overall survival was analyzed according to clinicopathological characteristics. Results: Among 113,845 patients with breast cancer, 473 MBC cases were included. The median duration of follow-up was 72 months. The median age at diagnosis was 60 and 48 years for MBC and female breast cancer, respectively. Most male patients (92.6%) underwent total mastectomy, while 50.4% of female patients underwent breast-conserving surgery. Among MBC, 63.2% received chemotherapy, and 83.9% of hormone receptor-positive male patients received endocrine therapy. In survival analysis, MBC demonstrated distinct 5-year overall survival patterns compared with female breast cancer, according to age at diagnosis. In women with breast cancer, the younger age group (≤40 years) demonstrated worse 5-year overall survival than did the older age group (>40 years) (91.3% vs 92.7%, p <0.05). While in MBC, the younger age group (≤40 years) demonstrated better 5-year overall survival than did the older age group (>40 years) (97.4% vs 86.4%, p <0.05). Discussion: In conclusion within this extensive cohort, we have revealed unique survival patterns in MBC that diverge from those observed in women with breast cancer. This study enhances our comprehension of MBC prognosis and can potentially shed light on unresolved questions, paving the way for future research in the realm of MBC.

Association of residual ductal carcinoma in situ with breast cancer treatment outcomes after neoadjuvant chemotherapy according to hormone receptor status.

PURPOSE: This research aimed to clarify the impact of residual ductal carcinoma in situ(DCIS) in surgical specimens obtained after neoadjuvant chemotherapy(NAC) for breast cancer on the associated prognosis outcomes. METHODS: This retrospective study was performed on a cohort of 1,009 patients who achieved pCR following NAC for breast cancer and underwent subsequent breast surgery at a single institution between January 2008 and December 2019. Overall survival, local recurrence-free survival, distant metastasis-free survival, and disease-free survival of the residual and non-residual DCIS groups were the outcomes compared, with further subgroup analysis performed according to hormone receptor status. RESULTS: 260 individuals (25.8%) presented with residual DCIS. Based on a median follow-up of 54.0 months, no significant differences in outcomes were observed between the two groups. Patients with residual DCIS and hormone receptor-negative (HR-) breast cancer demonstrated a significant decrease in distant metastasis-free survival (p = 0.030) compared to those without residual DCIS. In the HR + cohort, no significant difference was observed between the two groups. Multivariate analysis of the HR- cohort demonstrated a significant association between residual DCIS and an elevated risk for distant recurrence (hazard ratio = 2.3, 95% confidence interval = 1.01-5.20, p = 0.047). CONCLUSIONS: Residual DCIS following NAC may impact breast cancer outcomes, particularly with respect to the occurrence of distant metastasis in HR- patients. Therefore, clinicians must vigilantly monitor patients with residual DCIS after NAC, and further research is needed to expand our understanding of the clinical implications of residual DCIS.

Characteristics and risk factors of axillary lymph node metastasis of microinvasive breast cancer.

PURPOSE: To select patients who would benefit most from sentinel lymph node biopsy (SLNB) by investigating the characteristics and risk factors of axillary lymph node metastasis (ALNM) in microinvasive breast cancer (MIBC). METHODS: This retrospective study included 1688 patients with MIBC who underwent breast surgery with axillary staging at the Asan Medical Center from 1995 to 2020. RESULTS: Most patients underwent SLNB alone (83.5%). Seventy (4.1%) patients were node-positive, and the majority had positive lymph nodes < 10 mm, with micro-metastases occurring frequently (n = 37; 55%). Node-positive patients underwent total mastectomy and axillary lymph node dissection (ALND) more than breast-conserving surgery (BCS) and SLNB compared with node-negative patients (p < 0.001). In the multivariate analysis, independent predictors of ALNM included young age [odds ratio (OR) 0.959; 95% confidence interval (CI) 0.927-0.993; p = 0.019], ALND (OR 11.486; 95% CI 5.767-22.877; p < 0.001), number of lymph nodes harvested (≥ 5) (OR 3.184; 95% CI 1.555-6.522; p < 0.001), lymphovascular invasion (OR 6.831; 95% CI 2.386-19.557; p < 0.001), presence of multiple microinvasion foci (OR 2.771; 95% CI 1.329-5.779; p = 0.007), prominent lymph nodes in preoperative imaging (OR 2.675; 95% CI 1.362-5.253; p = 0.004), and hormone receptor positivity (OR 2.491; 95% CI 1.230-5.046; p = 0.011). CONCLUSION: Low ALNM rate (4.1%) suggests that routine SLNB for patients with MIBC is unnecessary but can be valuable for patients with specific risk factors. Ongoing trials for omitting SLNB in early breast cancer, and further subanalyses focusing on rare populations with MIBC are necessary.

Implementation of BRCA Test among Young Breast Cancer Patients in South Korea: A Nationwide Cohort Study.

PURPOSE: This study aimed to investigate the frequency of BRCA testing and related factors among young breast cancer patients (age < 40 years) in South Korea. MATERIALS AND METHODS: We conducted a nationwide retrospective cohort study using data from the Health Insurance Review and Assessment claims. Newly diagnosed breast cancer patients younger than 40 were included. Annual BRCA testing ratios (number of BRCA test recipients/the number of patients undergoing breast cancer surgery in each year) were analyzed by region and health care delivery system. We investigated the location of breast cancer diagnosis and BRCA testing. RESULTS: From January 2010 to December 2020, there were 25,665 newly diagnosed young breast cancer patients, of whom 12,186 (47.5%) underwent BRCA testing. The BRCA testing ratios increased gradually from 0.084 (154/1,842) in 2010 to 0.961 (1,975/2,055) in 2020. Medical aid (vs. health insurance) and undergoing surgery in metropolitan cities or others (vs. Seoul), general hospitals, and clinics (vs. tertiary hospitals) were associated with a lower likelihood of BRCA testing. While 97.8% of the patients diagnosed in Seoul underwent BRCA testing in Seoul, 22.9% and 29.2% of patients who were diagnosed in metropolitan areas and other regions moved to Seoul and underwent BRCA testing, respectively. CONCLUSION: The frequency of BRCA testing has increased over time in South Korea, with Seoul showing a particularly high rate of testing. About one-quarter of patients diagnosed with breast cancer outside of Seoul moved to Seoul and underwent BRCA testing.

Comparison of long-term oncological outcomes after central lumpectomy versus nipple-sparing breast-conserving surgery for centrally located breast cancer: a propensity score-matched study.

PURPOSE: To compare the oncological safety of nipple-sparing breast-conserving surgery (BCS) versus central lumpectomy for centrally located breast cancer (CLBC). METHODS: Patients who underwent BCS for CLBC at Asan Medical Center from 2007 to 2018 were reviewed retrospectively. The oncological outcomes of nipple-sparing BCS (NS-BCS) and central lumpectomy were compared using univariate and multivariate Cox regression analyses and compared again after 1:1 propensity score matching (PSM). RESULTS: The study included 306 patients who underwent NS-BCS and 106 patients who underwent central lumpectomy (median follow-up: 111 months). On multivariate analysis, central lumpectomy had a lower risk of local recurrence compared to NS-BCS, albeit without statistical significance (HR 0.14, 95% CI 0.02-1.24; p = 0.077). There was no significant difference in the risk of death (HR 0.14, 95% CI 0.01-1.68, p = 0.12). After PSM, each group had 106 patients. The 5-year and 10-year local recurrence-free survival rates were 94.2% and 92.9% for NS-BCS, and 99.1% and 99.1% for central lumpectomy, respectively (p = 0.031). There were no significant differences in overall survival, regional recurrence-free survival, or distant recurrence-free survival. Fifteen patients (4.9%) who underwent NS-BCS had ipsilateral breast tumor recurrence (IBTR), of which 40% were in the nipple-areolar complex and previous surgical sites. One patient (0.9%) who underwent central lumpectomy experienced an IBTR in a different quadrant. CONCLUSION: NS-BCS showed more local recurrence than central lumpectomy. When deciding whether to spare the nipple during BCS in CLBC, patients should be sufficiently informed about the risk of IBTR.

Diagnostic yield of contrast-enhanced abdominal staging CT in patients with initially diagnosed breast cancer.

PURPOSE: To estimate the diagnostic yield (DY) of abdominal staging CT for detecting breast cancer liver metastasis (BCLM) in patients with initially diagnosed breast cancer and to determine the indications for abdominal staging CT. METHODS: Patients with newly diagnosed breast cancer who underwent abdominal CT as an initial staging work-up between January 2019 and December 2020 were retrospectively analyzed. DY was calculated and analyzed according to patient age, type of treatments, histologic type, histologic grade, lymphovascular invasion, Ki-67 status, hormone receptor status, subtype, and the American Joint Committee on Cancer anatomical staging. RESULTS: A total of 2056 patients (mean age, 51 ± 11 years) were included. The DY of abdominal staging CT for detecting BCLM was 1.1 % (22 of 2056). DY was significantly higher in stage III than in stage I or II cancers (3.9 % [18 of 467] vs. 0 % [0 of 412] or 0.4 % [4 of 1158], respectively, p < .001), and in human epidermal growth factor receptor-2 (HER2)-enriched cancers than in luminal or triple negative cancers (2.9 % [16 of 560] vs. 0.4 % [4 of 1090] or 0.5 % [2 of 406], respectively, p < .001). CONCLUSIONS: The DY of abdominal staging CT for detecting BCLM was low among all patients with initially diagnosed breast cancer. However, although abdominal staging CT for detecting BCLM is probably unnecessary in all patients, it can be clinically useful in patients with stage III or human epidermal growth factor receptor-2-enriched breast cancers.

Long-term outcome in patients with nodal-positive breast cancer treated with sentinel lymph node biopsy alone after neoadjuvant chemotherapy.

PURPOSE: Sentinel lymph node biopsy (SLNB) has yet to be accepted as the standard staging procedure in node positive (cN1) breast cancer patients who had clinical complete response in the axilla (cN0) following neoadjuvant chemotherapy (NAC), due to the presumed high false negative rate associated with SLNB in such scenario. This study aimed to determine whether there is a significant difference in the axillary recurrence rate (ARR) and long-term survival in this group of patients, receiving SLNB alone versus axillary lymph node dissection (ALND). METHODS: A retrospective cohort of cN1 patients who were rendered cN0 by NAC from January 2014 to December 2018 were identified from the Asan Medical Center database. Patients' characteristics and outcomes were collected and analyzed. RESULTS: 902 cN1 patients treated with NAC and turned cN0 were identified. 477 (52.9%) patients achieved complete pathological response in the axilla (ypN0). At a median follow up of 65 months, ARR was 3.2% in the SLNB only group and 1.8% in the ALND group (p = 0.398). DFS and OS were significantly worse in patients with ALND as compared to patients with SLNB only (p = 0.011 and 0.047, respectively). We noted more patients in the ALND group had T3-4 tumor. In the subgroup analysis, we showed that in the T1-2 subgroup (n = 377), there was no statistically significant difference in DFS and OS (p = 0.242 and 0.671, respectively) between SLNB only and ALND group. CONCLUSION: Our findings suggest that cN1 patients who were converted to ypN0 following NAC may be safely treated with SLNB only.

Age-Related Incidence and Peak Occurrence of Contralateral Breast Cancer.

Importance: Young patients with breast cancer have higher risk for developing contralateral breast cancer (CBC) and have epidemiologic characteristics different from those of older patients. Objective: To examine the incidence and peak occurrence of CBC according to age at primary breast cancer (PBC) surgery. Design, Setting, and Participants: This cohort study included patients who were diagnosed with and underwent surgery for unilateral nonmetastatic breast cancer at Asan Medical Center, Korea, between January 1, 1999, and December 31, 2013, with follow-up through December 31, 2018. Data were analyzed from December 1, 2021, through April 30, 2023. Patients were divided into 2 groups according to their age at surgery for PBC: younger (≤35 years) vs older (>35 years). Main Outcomes and Measures: The main outcomes were cumulative incidence and hazard rate of CBC in the entire study population and in subgroups divided by cancer subtype, categorized according to hormone receptor (HR) and ERBB2 status. Results: A total of 16 251 female patients with stage 0 to III breast cancer were analyzed; all patients were Korean. The mean (SD) age was 48.61 (10.06) years; 1318 patients (8.11%) were in the younger group, and 14 933 (91.89%) were in the older group. Median follow-up was 107 months (IQR, 79-145 months). Compared with the older group, the younger group had significantly higher incidence of CBC (10-year cumulative incidence, 7.1% vs 2.9%; P < .001) and higher risk (hazard ratio, 2.10; 95% CI, 1.62-2.74) of developing CBC. The hazard rate, which indicates risk for developing CBC at a certain time frame, differed according to the subtype of primary cancer. In patients with the HR+/ERBB2- subtype, the risk increased continuously in both age groups. In patients with the triple negative subtype, the risk increased until approximately 10 years and then decreased in both age groups. Meanwhile, in the HR-/ERBB2+ subtype, risk peaked earlier, especially in the younger group (1.7 years since first surgery in the younger group and 4.8 years in the older group). Conclusions and Relevance: In this cohort study, patients aged 35 years or younger with breast cancer had a higher risk of developing CBC than older patients. Moreover, young patients with the HR-/ERBB2+ subtype tended to have a shorter interval for developing CBC. These findings might be useful in guiding treatment decisions, such as contralateral prophylactic mastectomy.

Factors in Parenting Stress in Young Patients With Breast Cancer and Implications for Children's Emotional Development: The PSYCHE Study.

Importance: The number of patients with breast cancer who have children is substantial. However, the emotional burden of this disease and its implication for childhood development remain largely unknown. Objective: To investigate the clinical factors in parenting stress in mothers with breast cancer and the association of maternal depression and parenting stress with their children's emotional development. Design, Setting, and Participants: This cross-sectional study involved a survey of females with stage 0 to 3 breast cancer and was conducted from June 2020 to April 2021 in Seoul, South Korea. Participants were aged 20 to 45 years and completed the Center for Epidemiologic Studies Depression-Revised scale and basic questionnaires on demographic and clinical characteristics. Participants with children completed the Korean Parenting Stress Index Short Form (K-PSI-SF), Child Behavior Checklist, Junior Temperament and Character Inventory, and Children's Sleep Habits Questionnaire. Exposure: Having children in patients with breast cancer. Main Outcomes and Measures: Multivariable logistic and linear regression analyses were performed to investigate the association between maternal depression and parenting stress. Results: A total of 699 females (mean [SD] age, 39.6 [4.6] years) were included, of whom 499 had children (mean [SD] age of children, 8.0 [2.7] years). Depression was more common in patients with children (odds ratio [OR], 2.25; 95% CI, 1.01-5.05) and patients who had gonadotropin-releasing hormone treatment (OR, 1.68; 95% CI, 1.15-2.44). Disease duration was inversely associated with depression (OR, 0.85; 95% CI, 0.76-0.96). Cancer-related factors were not associated with the K-PSI-SF score. Having children aged 6 years or older (ß = 3.09; 95% CI, 0.19-5.99); being the sole primary caregiver (ß = -3.43; 95% CI, -5.87 to -0.99); and reporting certain temperament (eg, novelty seeking: ß = 0.58; 95% CI, 0.46-0.71), emotional problems (eg, anxious/depressed: ß = 8.09; 95% CI, 3.34-12.83), and sleeping pattern (eg, bedtime resistance: ß = 0.57; 95% CI, 0.15-0.99) subscale scores in their children were associated with parenting stress. Depression and parenting stress were correlated (ß = 0.56; 95% CI, 0.45-0.66; P < .001). The emotional challenges encountered by children of mothers with breast cancer were not significantly different from reference values. Conclusions and Relevance: This study found that in patients with breast cancer, child-related factors and depression were significantly associated with parenting stress, but breast cancer-related factors were not correlated. The findings suggest that mothers with breast cancer are susceptible to both depression and parenting stress and that tailored counseling and support are needed.

Survival After Development of Contralateral Breast Cancer in Korean Patients With Breast Cancer.

Importance: Contralateral breast cancer (CBC) is the most frequently diagnosed primary cancer in patients with breast cancer. Although many studies have reported survival after the development of CBC, results have been inconsistent. Objective: To investigate whether the development of CBC is associated with survival among patients with breast cancer. Design, Setting, and Participants: This cohort study was conducted at the Asan Medical Center, Korea, among patients who were diagnosed with primary unilateral, nonmetastatic, stage 0 to III breast cancer between 1999 and 2013 and followed up through 2018. The median (IQR) follow-up was 107 (75-143) months. Patients were categorized into CBC and no-CBC groups by whether they developed CBC during the follow-up period. Data were analyzed from November 2021 to March 2023. Exposure: Development of CBC. Main outcomes and measures: Survival rates of CBC and no-CBC groups were compared using a time-dependent Cox proportional hazard model in the entire study population and in subgroup analyses by interval of CBC development and subtype of the primary breast cancer. Results: Among 16 251 patients with breast cancer (all Asian, specifically Korean; mean [SD] age, 48.61 [10.06] years), 418 patients developed CBC. There was no significant difference in overall survival between CBC and no-CBC groups (hazard ratio, 1.166; 95% CI, 0.820-1.657). Patients who developed CBC within 1.5 years after the surgery of the primary breast cancer had a higher risk for overall death during the study period (hazard ratio, 2.014; 95% CI, 1.044-3.886), and those who developed CBC after 1.5 years showed no significant difference in survival compared with the no-CBC group. Patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (ERBB2, formerly HER2)-negative breast cancer had a higher risk for overall death in the CBC group (hazard ratio, 1.882; 95% CI, 1.143-3.098) compared with the no-CBC group. Conclusions and Relevance: This study found that development of CBC in patients with breast cancer was not associated with survival but that early development of CBC after diagnosis of the primary breast cancer or development of CBC in patients with HR-positive/ERBB2-negative breast cancer was associated with survival. These results may provide valuable information for patients seeking advice on opting for contralateral prophylactic mastectomy.

Waiting Time for Breast Cancer Treatment in Korea: A Nationwide Cohort Study.

PURPOSE: This study aimed to analyze the waiting time for initial treatment after breast cancer diagnosis and determine the factors influencing treatment delay in South Korea. METHODS: This nationwide retrospective cohort study was conducted using the Health Insurance Review and Assessment data. The participants were classified according to the regions where their biopsy and treatment were performed (Seoul-Seoul, Metro-Metro, Other-Other, Metro-Seoul, Other-Seoul). Waiting time was analyzed according to regional subgroup, year of diagnosis, and type of treatment. Multivariable logistic regression models were constructed to identify the factors associated with treatment delay (after 30 days of diagnosis). RESULTS: A total of 133,514 participants newly diagnosed between January 2010 and December 2017 were included in the study. The median waiting time for initial treatment in the total population increased from 8 days, in 2010, to 14 days, in 2017. In the Seoul-Seoul group, the waiting time increased from 10 days, in 2010, to 16 days, in 2017. Although the median waiting time was approximately 10 days in the Metro-Metro and Other-Other groups, it was 27 and 24 days, in the Metro-Seoul and Other-Seoul group, respectively, in 2017. The proportion of delayed upfront surgery by more than 30 days was higher in the Metro-Seoul (odds ratio [OR], 8.088; 95% confidence interval [CI], 7.357-8.893; p < 0.001) and Other-Seoul (OR, 6.210; 95% CI, 5.717-6.750; p < 0.001) groups than in the Metro-Metro (OR, 1.468; 95% CI, 1.352-1.594; p < 0.001) and Other-Other (reference) groups. Previous medical history and treatment at tertiary hospital were observed as factors related to delayed surgery. CONCLUSION: Waiting times for breast cancer surgery have increased across all regions of Korea, with those traveling to Seoul experiencing particularly long wait times.

Survey of clinicians on the use of adjuvant therapy for premenopausal women with breast cancer.

PURPOSE: Considering prognostic and anatomic stages in early-stage premenopausal patients with breast cancer, clinicians decide on performing the multigene assay, adjuvant chemotherapy, or ovarian function suppression (OFS). This decision is also based on genetic information related to hormone receptor-positive and human epidermal growth factor receptor 2 negative results. We aimed to determine the tendency to use adjuvant therapy in clinical practice. METHODS: From April to May 2022, clinicians of the Korean Breast Cancer Society responded to a web-based survey. The survey included 62 multiple-choice questions mainly on decision-making under different pathologic conditions. RESULTS: Among 92 responding clinicians, 91.3% were breast surgeons. For 35-year-old patients (pT2N0 and Ki-67 50% profile), 96.8% of clinicians selected chemotherapy, whereas 50.7% selected chemotherapy for patients with pT1N0, Ki-67 10%, and without Oncotype Dx (ODX). Only 35.6% selected chemotherapy for 47-year-old patients with the same profiles, while 84.3% and 49.1% chose chemotherapy with ODX recurrence score 21 and 16, respectively. More clinicians selected tamoxifen (TMX) plus OFS than aromatase inhibitor (AI) plus OFS for 5 years of endocrine therapy in patients with adjuvant chemotherapy regardless of genomic and clinical risks. However, for the same patients without adjuvant chemotherapy, more clinicians selected AI plus OFS. A longer duration of additional OFS and TMX was selected in patients with high clinical and genomic risks, and the duration of OFS was relatively shorter in older patients. CONCLUSION: The decision regarding adjuvant therapy should be made considering clinical and genomic risks and age, and clinicians should consult with patients about adverse effects and compliance.

The Impact of a Mobile Support Group on Distress and Physical Activity in Breast Cancer Survivors: Randomized, Parallel-Group, Open-Label, Controlled Trial.

BACKGROUND: While mobile health apps have demonstrated their potential in revolutionizing health behavior changes, the impact of a mobile community built on these apps on the level of physical activity and mental well-being in cancer survivors remains unexplored. OBJECTIVE: In this randomized controlled trial, we examine the effects of participation in a mobile health community specifically designed for breast cancer survivors on their physical activity levels and mental distress. METHODS: We performed a single-center, randomized, parallel-group, open-label, controlled trial. This trial enrolled women between 20 and 60 years of age with stage 0 to III breast cancer, an Eastern Cooperative Oncology Group performance status of 0, and the capability of using their own smartphone apps. From January 7, 2019, to April 17, 2020, a total of 2,616 patients were consecutively screened for eligibility after breast cancer surgery. Overall, 202 patients were enrolled in this trial, and 186 patients were randomly assigned (1:1) to either the intervention group (engagement in a mobile peer support community using an app for tracking steps; n=93) or the control group (using the app for step tracking only; n=93) with a block size of 10 without stratification. The mobile app provides a visual interface of daily step counts, while the community function also provides rankings among its members and regular notifications encouraging physical activity. The primary end point was the rate of moderate to severe distress for the 24-week study period, measured through an app-based survey using the Distress Thermometer. The secondary end point was the total weekly steps during the 24-week period. RESULTS: After excluding dropouts, 85 patients in the intervention group and 90 patients in the control group were included in the analysis. Multivariate analyses showed that patients in the intervention group had a significantly lower degree of moderate to severe distress (B=-0.558; odds ratio 0.572; P<.001) and a higher number of total weekly step counts (B=0.125; rate ratio 1.132; P<.001) during the 24-week period. CONCLUSIONS: Engagement in a mobile app-based patient community was effective in reducing mental distress and increasing physical activity in breast cancer survivors. TRIAL REGISTRATION: ClinicalTrials.gov NCT03783481; https://classic.clinicaltrials.gov/ct2/show/NCT03783481.

Survival outcomes of breast cancer patients with recurrence after surgery according to period and subtype.

PURPOSE: To analyze and compare the survival rates of recurrent breast cancer patients in Korea between two periods (period I: 2000-2007; period II: 2008-2013) and to identify the factors associated with outcomes and changes over time in the duration of survival after recurrence. METHODS: We retrospectively analyzed 2,407 patients who had recurrent breast cancer with treated between January 2000 and December 2013 and divided them into two periods according to the year of recurrence. We reviewed the age at diagnosis, clinical manifestations, pathology report, surgical methods, types of adjuvant treatment, type of recurrence, and follow-up period. RESULTS: The median follow-up was 30.6 months (range, 0-223.4) from the time of relapse, and the median survival time was 42.3 months. Survival after recurrence (SAR) significantly improved from 38.0 months in period I to 49.7 months in period II (p < 0.001). In the analysis performed according to the hormone receptor and HER2 status subtypes, all subtypes except the triple-negative subtype showed higher SAR in period II than period I. Age at diagnosis, tumor stage, and treatment after recurrence were significantly correlated with survival outcomes. CONCLUSION: The survival outcomes of Korean patients with breast cancer after the first recurrence have improved in Korea. Such improvements may be attributed to advances in treatment.

Clinical significance of microinvasive breast cancer across the different subtypes and human epidermal growth factor receptor 2 expression levels.

PURPOSE: The clinical behavior, prognosis, and management of microinvasive breast cancer (MiBC) is controversial. We aimed to clarify its significance across different subtypes and the role of human epidermal growth factor receptor 2 (HER2) expression in MiBC. METHODS: We analyzed 1530 patients with T1mi (tumor size ≤ 0.1 cm), node-negative breast cancer who underwent breast conserving surgery or total mastectomy between 2001 and 2020 at the Asan Medical Center (AMC). RESULTS: When divided into four subtypes, hormone receptor (HR)+/HER2-, HR+ /HER2+ , HR-/HER2+ , and HR-/HER2-, HR-/HER2+ had the highest prevalence rate of 38.5% in MiBC patients. In a median follow-up period of 74 months (0-271 months), 103 (6.7%) patients had recurrent tumor, and 95 (6.2%) had local recurrence. Disease-free survival (DFS) and local recurrence-free survival (LRFS) were worst in the HR-/HER2+ group. The five-year DFS for the HR-/HER2+ group was 92.2%, while it was 97.1% for the HR+/HER2- group (p = 0.024 The five-year LRFS for HER2- patients were better than that of HER2+ MiBC patients, which were 97.1 and 93.8%, respectively (p = 0.010). Univariate and multivariate Cox regression analyses showed that the HR-/HER2+ group had relatively higher risk of recurrence compared to the HR+/HER2- group (hazard ratio [HR] = 2.332, 95% confidence interval [CI] 1.412-3.852, p = 0.001 unadjusted; HR = 3.346, 95% CI 1.408-7.953, p = 0.006 adjusted). CONCLUSION: HER2 overexpression was significantly associated with adverse clinicopathologic parameters and increased local recurrence risk in MiBC. Therefore, more understanding of the clinical behavior of HER2 in MiBC will enable tailoring of adjuvant therapy for these patients.

Non-sentinel node metastasis prediction during surgery in breast cancer patients with one to three positive sentinel node(s) following neoadjuvant chemotherapy.

Our aim was to develop a tool to accurately predict the possibility of non-sentinel lymph node metastasis (NSLNM) during surgery so that a surgeon might decide the extent of further axillary lymph node dissection intraoperatively for patients with 1-3 positive sentinel lymph node(s) (SLN) after neoadjuvant chemotherapy. After retrospective analysis of Asan Medical Center (AMC) database, we included 558 patients' records who were treated between 2005 and 2019. 13 factors were assessed for their utility to predict NSLNM with chi-square and logistic regression with a bootstrapped, backward elimination method. Based on the result of the univariate analysis for statistical significance, number of positive SLN(s), number of frozen nodes, Progesterone Receptor (PR) positivity, clinical N stage were selected for the multivariate analysis and were utilized to generate a nomogram for prediction of residual nodal disease. The resulting nomogram was tested for validation by using a patient group of more recent, different time window at AMC. We designed a nomogram to be predictive of the NSLNM which consisted of 4 components: number of SLN(s), number of frozen nodes, PR positivity, and clinical N stage before neoadjuvant chemotherapy. The Area under the receiver operating characteristics curve (AUC) value of this formula was 0.709 (95% CI, 0.658-0.761) for development set and 0.715 (95% CI, 0.634-0.796) for validation set, respectively. This newly created AMC nomogram may provide a useful information to a surgeon for intraoperative guidance to decide the extent of further axillary surgery.