Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45–65 Gy in 15–30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan–Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00–3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57–14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45–65 Gy in 15–30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan–Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00–3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57–14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45–65 Gy in 15–30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan–Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00–3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57–14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45–65 Gy in 15–30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan–Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00–3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57–14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). Materials and Methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45–65 Gy in 15–30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan–Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00–3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57–14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. Conclusion In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: Risk factors predicting distant metastasis (DM) in extrahepatic bile duct cancer (EHBDC) patients treated with curative resection were investigated. Materials and Methods: Medical records of 1,418 EHBDC patients undergoing curative resection between Jan 2000 and Dec 2015 from 14 institutions were reviewed. After resection, 924 patients (67.6%) were surveilled without adjuvant therapy, 297 (21.7%) were treated with concurrent chemoradiotherapy (CCRT) and 148 (10.8%) with CCRT followed by chemotherapy. To exclude the treatment effect from innate confounders, patients not treated with adjuvant therapy were evaluated. Results: After a median follow-up of 36.7 months (range, 2.7 to 213.2 months), the 5-year distant metastasis-free survival (DMFS) rate was 57.7%. On multivariate analysis, perihilar or diffuse tumor (hazard ratio [HR], 1.391; p=0.004), poorly differentiated histology (HR, 2.014; p < 0.001), presence of perineural invasion (HR, 1.768; p < 0.001), positive nodal metastasis (HR, 2.670; p < 0.001) and preoperative carbohydrate antigen (CA) 19-9 ≥ 37 U/mL (HR, 1.353; p < 0.001) were significantly associated with inferior DMFS. The DMFS rates significantly differed according to the number of these risk factors. For validation, patients who underwent adjuvant therapy were evaluated. In patients with ≥ 3 factors, additional chemotherapy after CCRT resulted in a superior DMFS compared with CCRT alone (5-year rate, 47.6% vs. 27.7%; p=0.001), but the benefit of additional chemotherapy was not observed in patients with 0-2 risk factors. Conclusion Tumor location, histologic differentiation, perineural invasion, lymph node metastasis, and preoperative CA 19-9 level predicted DM risk in resected EHBDC. These risk factors might help identifying a subset of patients who could benefit from additional chemotherapy after resection.

Purpose: This single-arm phase II trial investigate the efficacy and safety of S-1 plus oxaliplatin (SOX) in patients with metastatic breast cancer. Materials and Methods: Patients with metastatic breast cancer previously treated with anthracyclines and taxanes were enrolled. Patients received S-1 (40-60 mg depending on patient’s body surface area, twice a day, day 1-14) and oxaliplatin (130 mg/m2, day 1) in 3 weeks cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumor 1.1. Secondary endpoints included time-to-progression (TTP), duration-of-response (DoR), overall survival (OS), and adverse events. Results: A total of 87 patients were enrolled from 11 institutions in Korea. Hormone receptor was positive in 54 (62.1%) patients and six (6.9%) had human epidermal growth factor receptor 2–positive disease. Forty-eight patients (85.1%) had visceral metastasis and 74 (55.2%) had more than three sites of metastases. The ORR of SOX regimen was 38.5% (95% confidence interval [CI], 26.9 to 50.0) with a median TTP of 6.0 months (95% CI, 5.1 to 6.9). Median DoR and OS were 10.3 months (95% CI, 5.5 to 15.1) and 19.4 (95% CI, not estimated) months, respectively. Grade 3 or 4 neutropenia was reported in 28 patients (32.1%) and thrombocytopenia was observed in 23 patients (26.6%). Conclusion This phase II study showed that SOX regimen is a reasonable option in metastatic breast cancer previously treated with anthracyclines and taxanes.

Purpose: Cancer antigen 15-3 (CA15-3) is a serum tumor marker for breast cancer (BC) extensively used in clinical practice. CA15-3 is non-invasive, easily available, and a costeffective tumor marker for immediate diagnosis, monitoring and prediction of BC recurrence. We hypothesized that an elevation of CA15-3 may have prognostic impact in patients with early BC with normal serum CA15-3 level. Methods: This was a retrospective cohort study, which included patients with BC who received curative surgery at a comprehensive single institution between 2000 and 2016.CA15-3 levels from 0 to 30 U/mL were considered normal, and patients who had CA15-3 > 30 U/mL, were excluded from the study. Results: The mean age of study participants (n = 11,452) was 49.3 years. The proportion of participants with elevated CA15-3 ≥ 1 standard deviation (SD) compared with the previous examination during follow-up was 23.3% (n = 2,666). During the follow-up (median followup 5.8 years), 790 patients experienced recurrence. The fully-adjusted hazard ratio (HR) for recurrence comparing participants with stable CA15-3 level to subjects with elevated CA15-3 level was 1.76 (95% confidence interval [CI], 1.52–2.03). In addition, if the CA15-3was elevated ≥ 1 SD, the risk was much higher (HR, 6.87; 95% CI, 5.81–8.11) than in patients without elevated CA15-3 ≥ 1 SD. In sensitivity analysis, the recurrence risk was consistently higher in participants with elevated CA15-3 levels than in participants without elevated CA15-3 levels. The association between elevated CA15-3 levels and incidence of recurrence was observed in all subtypes and the association was stronger in patients with N+ than in patients with N0 stage (p-value for interaction < 0.01). Conclusion The results of the present study demonstrated that elevation of CA15-3 in patients with early BC and initial normal serum CA15-3 levels has a prognostic impact.

Purpose: Data on subsequent arm lymphedema (SAL) after salvage treatment for locoregional recurrence (LRR) of breast cancer are limited. We conducted a study to evaluate the risk of SAL in patients with LRR. Methods: We reviewed the data of patients with breast cancer who had LRR and were initially diagnosed between January 2003 and December 2017. Among the 214 patients who received curative salvage treatment, most had local (n = 125, 57.9%), followed by regional (n = 73, 34.1%), and locoregional (n = 16, 7.9%) recurrences. A competing risk analysis considering the factors of death and a second LRR were performed to exclude potential malignant lymphedema. We used the Fine-Gray subdistribution hazards model to estimate the hazard ratio (HR) for comparing the risk of SAL. Results: With a median follow-up duration of 41.4 months (interquartile range, 25.6–65.1), 51 patients (23.8%) experienced SAL with a median interval of 9.9 months after treatment.The two-year cumulative incidence of SAL was 12.7%. Among the 18 patients with initial lymphedema, nine (50.0%) developed SAL. Multivariate analysis revealed that a history of lymphedema (HR, 4.61; p < 0.001) and taxane-based salvage chemotherapy (HR, 2.38; p = 0.009) were significantly associated with SAL development. Conclusion Salvage treatment for LRR-induced SAL was performed in 24% of the patients.A history of initial lymphedema and salvage taxane-based chemotherapy increases the risk of developing SAL. Therefore, close surveillance for the incidence of SAL is required in patients opting for salvage treatment for LRR.

Purpose: Trastuzumab has markedly improved the survival outcomes of patients with human epidermal growth factor receptor 2 (HER2)–positive breast cancer, and dual blockade of HER2 using trastuzumab and pertuzumab in combination with taxanes (THP) has become a standard of care for HER2-positive metastatic breast cancer (MBC) worldwide since the CLEOPATRA trial. We assessed the outcomes of THP as a first-line treatment for Korean HER2-positive MBC patients in the real-world setting. Materials and Methods: Between August 2008 and October 2020, we identified 228 HER2-positive MBC patients who received THP as a first-line palliative chemotherapy. We analyzed survival outcomes, efficacy, and adverse events of THP retrospectively. Results: After a median follow-up duration of 28.7 months, median overall survival and progression-free survival were 58.3 months (95% confidence interval [CI], 36.6 to 80.0) and 19.1 months (95% CI, 16.2 to 21.9), respectively. Better survival outcomes were observed in patient who received docetaxel for more than six cycles. Patients exposed to anti-HER2 directed therapies in a perioperative setting had poor survival outcomes. The overall response rate was 86.8% with a complete response (CR) rate of 17.7%. Among responders, 16.7% of patients sustained THP over 35 months and showed better survivals and higher CR rates. Adverse events were comparable to those reported in previous studies. Conclusion In a real-world context, clinical outcomes of Korean HER2-positive MBC patients treated with THP were similar to those of patients in the CLEOPATRA trial. Much longer follow-up results would be warranted.