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.

Contribution of tumour and immune cells to PD-L1 expression as a predictive biomarker in metastatic triple-negative breast cancer: exploratory analysis from KEYNOTE-119.

The efficacy of pembrolizumab monotherapy versus chemotherapy increased with increasing programmed death ligand 1 (PD-L1) expression, as quantified by combined positive score (CPS; PD-L1 expression on both tumour cells and immune cells) in patients with previously treated metastatic triple-negative breast cancer (mTNBC) in the phase 3 KEYNOTE-119 study. This exploratory analysis was conducted to determine whether the expression of PD-L1 on tumour cells contributes to the predictive value of PD-L1 CPS in mTNBC. PD-L1 expression in tumour samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified using both CPS and tumour proportion score (TPS; PD-L1 expression on tumour cells alone). Calculated immune cell density (CID) was defined as CPS minus TPS. The ability of each scoring method (CPS, TPS, and CID) to predict clinical outcomes with pembrolizumab was evaluated. With pembrolizumab, the area under the receiver operating characteristic curve was 0.69 (95% CI = 0.58-0.80) for CPS, 0.55 (95% CI = 0.46-0.64) for TPS, and 0.67 (95% CI = 0.56-0.77) for CID. After correction for cutoff prevalence, CPS performed as well as, if not better than, CID with respect to predicting objective response rate, progression-free survival, and overall survival. Data from this exploratory analysis suggest that, although PD-L1 expression on immune cells alone is predictive of response to programmed death 1 blockade in mTNBC, adding tumour PD-L1 expression assessment (i.e. CPS, which combines immune cell and tumour cell PD-L1 expression) may improve prediction. PD-L1 CPS thus remains an effective and broadly applicable uniform scoring system for enriching response to programmed death 1 blockade with pembrolizumab in mTNBC as well as other tumour types.

Patient-Reported Outcomes in OlympiA: A Phase III, Randomized, Placebo-Controlled Trial of Adjuvant Olaparib in gBRCA1/2 Mutations and High-Risk Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer.

PURPOSE: The OlympiA randomized phase III trial compared 1 year of olaparib (OL) or placebo (PL) as adjuvant therapy in patients with germline BRCA1/2, high-risk human epidermal growth factor receptor 2-negative early breast cancer after completing (neo)adjuvant chemotherapy ([N]ACT), surgery, and radiotherapy. The patient-reported outcome primary hypothesis was that OL-treated patients may experience greater fatigue during treatment. METHODS: Data were collected before random assignment, and at 6, 12, 18, and 24 months. The primary end point was fatigue, measured with the Functional Assessment of Chronic Illness Therapy-Fatigue scale. Secondary end points, assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Core 30 item, included nausea and vomiting (NV), diarrhea, and multiple functional domains. Scores were compared between treatment groups using mixed model for repeated measures. Two-sided P values <.05 were statistically significant for the primary end point. All secondary end points were descriptive. RESULTS: One thousand five hundred and thirty-eight patients (NACT: 746, ACT: 792) contributed to the analysis. Fatigue severity was statistically significantly greater for OL versus PL, but not clinically meaningfully different by prespecified criteria (≥3 points) at 6 months (diff OL v PL: NACT: -1.3 [95% CI, -2.4 to -0.2]; P = .022; ACT: -1.3 [95% CI, -2.3 to -0.2]; P = .017) and 12 months (NACT: -1.6 [95% CI, -2.8 to -0.3]; P = .017; ACT: -1.3 [95% CI, -2.4 to -0.2]; P = .025). There were no significant differences in fatigue severity between treatment groups at 18 and 24 months. NV severity was worse in patients treated with OL compared with PL at 6 months (NACT: 6.0 [95% CI, 4.1 to 8.0]; ACT: 5.3 [95% CI, 3.4 to 7.2]) and 12 months (NACT: 6.4 [95% CI, 4.4 to 8.3]; ACT: 4.5 [95% CI, 2.8 to 6.1]). During treatment, there were some clinically meaningful differences between groups for other symptoms but not for function subscales or global health status. CONCLUSION: Treatment-emergent symptoms from OL were limited, generally resolving after treatment ended. OL- and PL-treated patients had similar functional scores, slowly improving during the 24 months after (N)ACT and there was no clinically meaningful persistence of fatigue severity in OL-treated patients.

A nationwide real-world study for evaluation of effectiveness and safety of T-DM1 in patients with HER2-positive metastatic breast cancer in Korea (KCSG BR19-15).

Purpose: This study aimed to investigate clinical practices and factors related to the outcomes of T-DM1 use in patients with HER2-positive metastatic breast cancer (mBC). Methods: We included patients with HER2-positive mBC who received T-DM1 as a palliative therapy between August 2017 and December 2018. The safety and outcomes of T-DM1, including overall response rate (ORR), progression-free survival (PFS), and overall survival (OS), were evaluated. A Cox proportional hazards model was used to estimate the hazard ratio and 95% confidence interval (CI) for mortality or progression to HER2-positive mBC. Results: In total, 824 patients were enrolled during the study period. The mean age of patients was 58 years, and 516 (62.6%) patients relapsed after curative treatment. Excluding a history of endocrine therapy, 341 (41.4%) patients previously received none or first-line chemotherapy, 179 (21.7%) received second-line therapy, and 303 (36.9%) received third-or later-line chemotherapy before T-DM1 therapy. During a median follow-up of 16.8 months, the ORR was 35%, the median PFS was 6.6 months, and the median OS was not reached. The clinical factors associated with the hazard of progression were age (<65 years), poor performance status (⩾2), advanced line of palliative chemotherapy (⩾2), prior pertuzumab use, and treatment duration of palliative trastuzumab (<10 months). Common grade 3-4 adverse events were thrombocytopenia (n = 107, 13.2%), neutropenia (n = 23, 2.8%), anemia (n = 21, 2.6%), and elevated liver enzyme (n = 20, 2.5%). Hypokalemia (⩽3.0 mmol/L) and any-grade bleeding events occurred in 25 (3.1%) and 94 (22.6%) patients, respectively. Conclusion: This is the first nationwide real-world study of T-DM1 use in patients with HER2-positive mBC in Korea. The effectiveness and toxicity profiles of T-DM1 in real-world practice were comparable to those in randomized trials. Moreover, patient factors and previous anti-HER2 therapy could predict the outcomes of T-DM1 therapy.

TROPION-Breast01: Datopotamab deruxtecan vs chemotherapy in pre-treated inoperable or metastatic HR+/HER2- breast cancer.

Improving the prognosis for patients with metastatic HR+/HER2- breast cancer remains an unmet need. Patients with tumors that have progressed on endocrine therapy and/or are not eligible for endocrine therapy had limited treatment options beyond chemotherapy. Antibody-drug conjugates are a novel and promising treatment class in this setting. Datopotamab deruxtecan (Dato-DXd) consists of a TROP2-directed humanized IgG1 monoclonal antibody attached via a serum-stable cleavable linker to a topoisomerase I inhibitor payload. TROPION-Breast01 is an ongoing phase III study that is evaluating the efficacy and safety of Dato-DXd compared with investigator's choice of standard-of-care chemotherapy in patients with inoperable or metastatic HR+/HER2- breast cancer who have received one or two prior lines of systemic chemotherapy in the inoperable or metastatic setting. Clinical Trial Registration: NCT05104866 (ClinicalTrials.gov).

Antibody-drug conjugates are a type of drug with two parts: an antibody that directs the drug to the cancer cells and a cancer-cell killing toxic payload. By binding to cancer cells before releasing the payload, treatment is directed to the site of action so there are fewer side effects in the rest of the body. Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugates made up of datopotamab (antibody) and DXd (payload) which are joined together via a stable linker. Datopotamab binds to a protein found on cancer cells called TROP2; it then goes inside and releases the DXd payload to kill the tumor cells. DXd may leak out to surrounding cancer cells and kill those as well. The TROPION-Breast01 study is comparing Dato-DXd with standard-of-care chemotherapy. Around 700 patients will take part, who have: Tumors that cannot be surgically removed. Tumors that are hormone receptor-positive and do not have HER2 overexpression. Had one or two lines of previous chemotherapy (after the tumor could not be surgically removed, or had spread). Had tumor growth despite hormonal therapy or are ineligible for hormonal therapy. Patients who meet the entry criteria will be randomly assigned to a treatment group in equal numbers to either Dato-DXd or an appropriate chemotherapy, out of four options chosen by the treating doctor. At the end of the study, researchers will look at whether the patients who receive Dato-DXd live longer without their breast cancer getting worse, compared with patients who receive chemotherapy. This study is also looking at how the treatment affects patients' quality of life.

Pemetrexed plus vinorelbine versus vinorelbine monotherapy in patients with metastatic breast cancer (KCSG-BR15-17): A randomized, open-label, multicenter, phase II trial.

INTRODUCTION: Metastatic breast cancer refractory to anthracycline and taxanes often shows rapid progression. The development of effective and tolerable combination regimens for these patients is needed. This phase II trial investigated the efficacy of pemetrexed plus vinorelbine in patients with metastatic breast cancer. METHODS: This randomized, open-label, phase II trial was conducted in 17 centers in Korea. Patients with advanced breast cancer who had previously been treated with anthracyclines and taxanes were randomly assigned in a 1:1 ratio to receive either vinorelbine or pemetrexed plus vinorelbine. Randomization was stratified by prior capecitabine treatment and hormone receptor status. The primary endpoint was investigator-assessed progression-free survival (PFS). Secondary endpoints included the objective response rate, overall survival, safety, and quality of life. RESULTS: Between March 2017 and August 2019, a total of 125 patients were enrolled. After a median follow-up duration of 14.1 months, 118 progression events and 88 death events had occurred. Sixty-two patients were assigned to the pemetrexed plus vinorelbine arm, and 63 were assigned to the vinorelbine arm. Pemetrexed plus vinorelbine significantly prolonged PFS compared to vinorelbine (5.7 vs. 1.5 months, p < 0.001). The combination arm had higher disease control rate (76.8% vs. 45.9%, p = 0.001) and a tendency toward longer overall survival (16.8 vs. 10.5 months, p = 0.102). Anemia was more frequent in the pemetrexed plus vinorelbine arm per cycle compared with vinorelbine (7.9% vs. 1.9%, p < 0.001), but there was no difference in the incidence of grade 3-4 neutropenia per cycle between the pemetrexed plus vinorelbine arm and the vinorelbine single arm (14.7% vs. 19.5%, p = 0.066). CONCLUSIONS: This phase II study showed that pemetrexed plus vinorelbine led to a longer PFS than vinorelbine. Adverse events of pemetrexed plus vinorelbine were generally manageable.

Impact of pembrolizumab versus chemotherapy on health-related quality of life in patients with metastatic triple-negative breast cancer: results from the phase 3 randomised KEYNOTE-119 study.

BACKGROUND: In KEYNOTE-119 (ClinicalTrials.gov, NCT02555657), overall survival (primary end-point) was similar between pembrolizumab and chemotherapy in patients with previously treated metastatic triple-negative breast cancer (TNBC), although the pembrolizumab treatment effect increased with tumour PD-L1 expression. We report results of prespecified health-related quality of life (HRQoL) analyses from KEYNOTE-119. METHODS: Eligible patients were randomised 1:1 to pembrolizumab 200 mg Q3W intravenously for up to 35 cycles or treatment of physician's choice per local/country guidelines. Prespecified exploratory end-points were the change from baseline in HRQoL (EORTC QLQ-C30, QLQ-BR23) and to characterise utilities (EQ-5D-3L). Time to deterioration (TTD) was the time from start of treatment to first onset of a ≥10-point worsening from baseline. RESULTS: HRQoL analyses included 187 patients with tumour PD-L1 combined positive score (CPS) ≥10. Changes from baseline at 6 weeks (primary analysis time point) were directionally better with pembrolizumab versus chemotherapy for QLQ-C30 GHS/QoL (between-group difference in least-squares mean scores of 4.21 [95% CI, -1.38 to 9.80]), QLQ-C30 functional scales (physical, role, cognitive, social), QLQ-C30 symptom scales/items (fatigue, nausea/vomiting, dyspnoea, appetite loss), and QLQ-BR23 symptom scales/items (systemic therapy side-effects, upset by hair loss). Median TTD was directionally longer for pembrolizumab versus chemotherapy for QLQ-C30 QHS/QoL (4.3 versus 1.7 months), QLQ-C30 nausea/vomiting (7.7 versus 4.8 months), and QLQ-BR23 systemic therapy side-effects (6.1 versus 3.4 months). Minimal treatment differences were observed for other HRQoL end-points. CONCLUSIONS: HRQoL results were consistent with clinical outcomes and appeared to be driven by results for patients with tumour PD-L1 CPS ≥10.

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.

Safety and Tolerability of a Novel Anti-HER2 Antibody-Drug Conjugate (PF-06804103) in Patients with HER2-Expressing Solid Tumors: A Phase 1 Dose-Escalation Study.

PF-06804103 is an anti-HER2 antibody-drug conjugate with auristatin payload. We evaluated its safety, tolerability, and antitumor activity in patients with advanced/unresectable or metastatic breast and gastric cancers. This multicenter, open-label, first-in-human, phase 1 study (NCT03284723) comprised dose escalation (P1) and dose expansion (P2). In P1, adults with HER2+ breast or gastric cancer received PF-06804103 0.15-5.0 mg/kg intravenously once/21 days (Q3W); in P2, patients with HER2+ or HER2-low (IHC 1+ or IHC 2+/ISH-) breast cancer received 3.0 or 4.0 mg/kg Q3W. The primary endpoints were dose-limiting toxicities (DLT) and safety (P1), and objective response rate (ORR) assessed using RECIST v1.1 (P2). Ninety-three patients enrolled in P1 (n = 47: HER2+ gastric cancer = 22, HER2+ breast cancer = 25) and P2 [n = 46: HER2+ breast cancer = 19, hormone receptor (HR)+ HER2-low breast cancer = 27] received PF-06804103. Four patients (3.0- and 4.0-mg/kg groups, n = 2 each) had DLTs (mostly Grade 3). Safety and efficacy results showed a dose-response relationship. Adverse events (AE) leading to treatment discontinuation (44/93, 47.3%) included neuropathy (11/93, 11.8%), skin toxicity (9/93, 9.7%), myalgia (5/93, 5.4%), keratitis (3/93, 3.2%), and arthralgia (2/93, 2.2%). Two (2/79, 2.5%) patients (P1, 4.0- and 5.0-mg/kg groups, n = 1 each) achieved complete response; 21 (21/79, 26.6%) achieved partial response. In P2, ORR was higher in HER2+ compared with HR+ HER2-low breast cancer [3.0 mg/kg: 16.7% (2/12) vs. 10.0% (1/10); 4.0 mg/kg: 47.4% (9/19) vs. 27.3% (3/11)]. PF-06804103 demonstrated antitumor activity; however, AEs led to discontinuation in 47.3% of patients. Safety and efficacy were dose-dependent.

Establishment of Patient-Derived Organoids Using Ascitic or Pleural Fluid from Cancer Patients.

PURPOSE: Patient-derived tumor cells can be a powerful resource for studying pathophysiological mechanisms and developing robust strategies for precision medicine. However, establishing organoids from patient-derived cells is challenging because of limited access to tissue specimens. Therefore, we aimed to establish organoids from malignant ascites and pleural effusions. MATERIALS AND METHODS: Ascitic or pleural fluid from pancreatic, gastric, and breast cancer patients was collected and concentrated to culture tumor cells ex vivo. Organoids were considered to be successfully cultured when maintained for five or more passages. Immunohistochemical staining was performed to compare the molecular features, and drug sensitivity was assayed to analyze the clinical responses of original patients. RESULTS: We collected 70 fluid samples from 58 patients (pancreatic cancer, n=39; gastric cancer, n=21; and breast cancer, n=10). The overall success rate was 40%; however, it differed with types of malignancy, with pancreatic, gastric, and breast cancers showing 48.7%, 33.3%, and 20%, respectively. Cytopathological results significantly differed between successful and failed cases (p=0.014). Immunohistochemical staining of breast cancer organoids showed molecular features identical to those of tumor tissues. In drug sensitivity assays, pancreatic cancer organoids recapitulated the clinical responses of the original patients. CONCLUSION: Tumor organoids established from malignant ascites or pleural effusion of pancreatic, gastric, and breast cancers reflect the molecular characteristics and drug sensitivity profiles. Our organoid platform could be used as a testbed for patients with pleural and peritoneal metastases to guide precision oncology and drug discovery.

Risk Factors for Palbociclib-Induced Early Developing Neutropenia in Patients with Hormone Receptor-Positive Metastatic Breast Cancer.

PURPOSE: This study aimed to determine the risk factors for palbociclib-induced grade 4 or grade 3 neutropenia (NP) requiring dose reduction or delayed treatment in patients with HR+/HER2-metastatic breast cancer in the first 3 cycles (early grade 3/4 NP) and whether the early developing grade 3/4 NP affects progression-free survival. METHODS: A retrospective study using electronic medical records was conducted on patients who received palbociclib for metastatic breast cancer between January 2018 and August 2022. The early grade 3/4 NP risk factors were evaluated with univariate and multivariable logistic regression analyses. In addition, the Kaplan-Meier method was used to estimate the median progression-free survival (PFS) to analyze the effect of early grade 3/4 NP on treatment. RESULTS: Out of the 264 patients included in this study, 173 (65.6%) experienced early grade 3/4 NP. A total of four models were applied for multivariable analysis to identify early grade 3/4 NP-developing factors. Low baseline ANC, WBC, PLT, and BSA were significant risk factors for early grade 3/4 NP; baseline ANC < 3700/mm3, WBC < 6.30 × 109/mm3, PLT < 230 × 109/mm3, and BSA < 1.58 m2 increased the risk by approximately 4.0-fold, 3.7-4.0-fold, 2.1-fold, and 2.0-fold, respectively. Early grade 3/4 NP did not affect PFS (p = 0.710), although patients with early grade 3/4 NP had more frequent dose reductions or treatment delays. CONCLUSIONS: Based on the results, low baseline ANC, WBC, PLT, and BSA were associated with early grade 3/4 NP. Patients with risk factors require careful monitoring, and this study is expected to help predict NP, which may appear in early treatment.

A Multicenter, Prospective, Observational Study to Evaluate Ethanol-Induced Symptoms in Patients Receiving Docetaxel Chemotherapy.

PURPOSE: Several previous studies and case reports have reported ethanol-induced symptoms in patients receiving anticancer drugs containing ethanol. Most docetaxel formulations contain ethanol as a solvent. However, there are insufficient data on ethanol-induced symptoms when docetaxel-containing ethanol is administered. The primary purpose of this study was to investigate the frequency and pattern of ethanol-induced symptoms during and after docetaxel administration. The secondary purpose was to explore the risk factors for ethanol-induced symptoms. MATERIALS AND METHODS: This was a prospective, multicenter, observational study. The participants filled out ethanol-induced symptom questionnaire on the day of chemotherapy and the following day. RESULTS: Data from 451 patients were analyzed. The overall occurrence rate of ethanol-induced symptoms was 44.3% (200/451 patients). The occurrence rate of facial flushing was highest at 19.7% (89/451 patients), followed by nausea in 18.2% (82/451 patients), and dizziness in 17.5% (79/451 patients). Although infrequent, unsteady walking and impaired balance occurred in 4.2% and 3.3% of patients, respectively. Female sex, presence of underlying disease, younger age, docetaxel dose, and docetaxel-containing ethanol amount were significantly associated with the occurrence of ethanol-induced symptoms. CONCLUSION: The occurrence of ethanol-induced symptoms was not low in patients receiving docetaxel-containing ethanol. Physicians need to pay more attention to the occurrence of ethanol-induced symptoms and prescribe ethanol-free or low-ethanol-containing formulations to high-risk patients.

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.

Eflapegrastim versus Pegfilgrastim for Chemotherapy-Induced Neutropenia in Korean and Asian Patients with Early Breast Cancer: Results from the Two Phase III ADVANCE and RECOVER Studies.

PURPOSE: We investigated the consistent efficacy and safety of eflapegrastim, a novel long-acting granulocyte-colony stimulating factor (G-CSF), in Koreans and Asians compared with the pooled population of two global phase 3 trials. Materials and Methods: Two phase 3 trials (ADVANCE and RECOVER) evaluated the efficacy and safety of fixed-dose eflapegrastim (13.2 mg/0.6 mL [3.6 mg G-CSF equivalent]) compared to pegfilgrastim (6 mg based on G-CSF) in breast cancer patients who received neoadjuvant or adjuvant docetaxel/cyclophosphamide. The primary objective was to demonstrate non-inferiority of eflapegrastim compared to pegfilgrastim in mean duration of severe neutropenia (DSN) in cycle 1, in Korean and Asian subpopulations. RESULTS: Among a total of 643 patients randomized to eflapegrastim (n=314) or pegfilgrastim (n=329), 54 Asians (29 to eflapegrastim and 25 to pegfilgrastim) including 28 Koreans (14 to both eflapegrastim and pegfilgrastim) were enrolled. The primary endpoint, DSN in cycle 1 in the eflapegrastim arm was non-inferior to the pegfilgrastim arm in Koreans and Asians. The DSN difference between the eflapegrastim and pegfilgrastim arms was consistent across populations: -0.120 days (95% confidence interval [CI], -0.227 to -0.016), -0.288 (95% CI, -0.714 to 0.143), and -0.267 (95% CI, -0.697 to 0.110) for pooled population, Koreans and Asians, respectively. There were few treatment-related adverse events that caused discontinuation of eflapegrastim (1.9%) or pegfilgrastim (1.5%) in total and no notable trends or differences across patient populations. CONCLUSION: This study may suggest that eflapegrastim showed non-inferior efficacy and similar safety compared to pegfilgrastim in Koreans and Asians, consistently with those of pooled population.

A Phase II Trial of S-1 and Oxaliplatin in Patients with Metastatic Breast Cancer Previously Treated with Anthracycline and Taxane (KCSG-BR07-03).

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.

Impacts of Subtype on Clinical Feature and Outcome of Male Breast Cancer: Multicenter Study in Korea (KCSG BR16-09).

PURPOSE: The treatment of male breast cancer (MBC) has been extrapolated from female breast cancer (FBC) because of its rarity despite their different clinicopathologic characteristics. We aimed to investigate the distribution of intrinsic subtypes based on immunohistochemistry, their clinical impact, and treatment pattern in clinical practice through a multicenter study in Korea. MATERIALS AND METHODS: We retrospectively analyzed clinical data of 248 MBC patients from 18 institutions across the country from January 1995 to July 2016. RESULTS: The median age of MBC patients was 63 years (range, 25 to 102 years). Among 148 intrinsic subtype classified patients, 61 (41.2%), 44 (29.7%), 29 (19.5%), and 14 (9.5%) were luminal A, luminal B, human epidermal growth factor receptor 2, and triple-negative breast cancer, respectively. Luminal A subtype showed trends for superior survival compared to other subtypes. Most hormone receptor-positive patients (166 patients, 82.6%) received adjuvant endocrine treatment. Five-year completion of adjuvant endocrine treatment was associated with superior disease-free survival (DFS) in patients classified with an intrinsic subtype (hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04 to 0.49; p=0.002) and in all patients (HR, 0.16; 95% CI, 0.05 to 0.54; p=0.003). CONCLUSION: Distribution of subtypes of MBC was similar to FBC and luminal type A was most common. Overall survival tended to be improved for luminal A subtype, although there was no statistical significance. Completion of adjuvant endocrine treatment was associated with prolonged DFS in intrinsic subtype classified patients. MBC patients tended to receive less treatment. MBC patients should receive standard treatment according to guidelines as FBC patients.

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.

Phase II study to investigate the efficacy of trastuzumab biosimilar (Herzuma®) plus treatment of physician's choice (TPC) in patients with heavily pretreated HER-2+ metastatic breast cancer (KCSG BR 18-14/KM10B).

We investigated the efficacy and safety of a trastuzumab biosimilar, Herzuma®, in combination with treatment of physician's choice (TPC) in patients with HER2+ metastatic breast cancer (MBC) who had failed at least two HER2 directed chemotherapies.

Response Rate and Safety of a Neoadjuvant Pertuzumab, Atezolizumab, Docetaxel, and Trastuzumab Regimen for Patients With ERBB2-Positive Stage II/III Breast Cancer: The Neo-PATH Phase 2 Nonrandomized Clinical Trial.

Importance: Addition of immune checkpoint inhibitors to anti-ERBB2 treatment has shown synergistic efficacy in preclinical studies and is thus worth investigating as a neoadjuvant treatment to maximize efficacy and to minimize toxic effects. Objective: To determine if neoadjuvant atezolizumab, docetaxel, trastuzumab, and pertuzumab therapy for ERBB2-positive early breast cancer warrants continuation to the next phase. Design, Setting, and Participants: This nonrandomized, open label, multicenter, phase 2 trial was conducted by the Korean Cancer Study Group and enrolled patients across 6 institutions in Korea from May 2019 to May 2020. Eligible patients were diagnosed with ERBB2-positive breast cancer (primary tumor size >2 cm or pathologically confirmed lymph node-positive cancer, without distant metastases) with a clinical stage of II or III. Interventions: Patients received 6 cycles of neoadjuvant pertuzumab (840 mg at first cycle, 420 mg during subsequent cycles), atezolizumab (1200 mg), docetaxel (75 mg/m2), and trastuzumab (600 mg via subcutaneous injection) every 3 weeks, followed by surgery. Patients with pathologic complete response (pCR) received 12 cycles of adjuvant atezolizumab, trastuzumab, and pertuzumab every 3 weeks after surgery. Patients without pCR were treated with 14 cycles of atezolizumab, 1200 mg, plus trastuzumab emtansine, 3.6 mg/kg, every 3 weeks. Main Outcomes and Measures: The primary end point was pCR rate, which was defined as the absence of invasive cancer cells in the primary tumor and regional lymph nodes (ypT0/isN0). Secondary end points included clinical objective response rate, 3-year event-free survival rate according to pCR achievement, disease-free survival, overall survival, toxic effects, and quality-of-life outcomes. Results: A total of 67 women (median [range] age, 52 [33-74] years) were enrolled. Hormone receptor expression was positive in 32 (48%) patients. Curative surgery was performed in 65 patients because 2 patients showed disease progression during neoadjuvant treatment and their tumors became unresectable. The overall pCR rate was 61% (41 of 67 patients). The pCR rate was higher in hormone receptor-negative disease vs hormone receptor-positive disease (27 of 35 [77%] patients vs 14 of 32 [44%] patients) and in programmed cell death 1-positive expression vs programmed cell death 1-negative expression (13 of 13 [100%] patients vs 28 of 53 [53%] patients). Grade 3 and 4 neutropenia and febrile neutropenia occurred in 8 (12%) patients and 5 (8%) patients, respectively. Grade 3 and 4 immune-related adverse events occurred in only 4 patients (grade 3 skin rash, encephalitis, hepatitis, and fever). No treatment-related death occurred during the neoadjuvant phase. Conclusions and Relevance: In this nonrandomized clinical trial, treatment with the neoadjuvant atezolizumab, docetaxel, trastuzumab, and pertuzumab regimen in patients with stage II or III ERBB2-positive breast cancer appears to have had an acceptable pCR rate and modest toxic effects. Further investigation of this immunotherapy combination in ERBB2-positive early breast cancer is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT03881878.

Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer.

BACKGROUND: Among breast cancers without human epidermal growth factor receptor 2 (HER2) amplification, overexpression, or both, a large proportion express low levels of HER2 that may be targetable. Currently available HER2-directed therapies have been ineffective in patients with these "HER2-low" cancers. METHODS: We conducted a phase 3 trial involving patients with HER2-low metastatic breast cancer who had received one or two previous lines of chemotherapy. (Low expression of HER2 was defined as a score of 1+ on immunohistochemical [IHC] analysis or as an IHC score of 2+ and negative results on in situ hybridization.) Patients were randomly assigned in a 2:1 ratio to receive trastuzumab deruxtecan or the physician's choice of chemotherapy. The primary end point was progression-free survival in the hormone receptor-positive cohort. The key secondary end points were progression-free survival among all patients and overall survival in the hormone receptor-positive cohort and among all patients. RESULTS: Of 557 patients who underwent randomization, 494 (88.7%) had hormone receptor-positive disease and 63 (11.3%) had hormone receptor-negative disease. In the hormone receptor-positive cohort, the median progression-free survival was 10.1 months in the trastuzumab deruxtecan group and 5.4 months in the physician's choice group (hazard ratio for disease progression or death, 0.51; P<0.001), and overall survival was 23.9 months and 17.5 months, respectively (hazard ratio for death, 0.64; P = 0.003). Among all patients, the median progression-free survival was 9.9 months in the trastuzumab deruxtecan group and 5.1 months in the physician's choice group (hazard ratio for disease progression or death, 0.50; P<0.001), and overall survival was 23.4 months and 16.8 months, respectively (hazard ratio for death, 0.64; P = 0.001). Adverse events of grade 3 or higher occurred in 52.6% of the patients who received trastuzumab deruxtecan and 67.4% of those who received the physician's choice of chemotherapy. Adjudicated, drug-related interstitial lung disease or pneumonitis occurred in 12.1% of the patients who received trastuzumab deruxtecan; 0.8% had grade 5 events. CONCLUSIONS: In this trial involving patients with HER2-low metastatic breast cancer, trastuzumab deruxtecan resulted in significantly longer progression-free and overall survival than the physician's choice of chemotherapy. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast04 ClinicalTrials.gov number, NCT03734029.).