Impact of HIV status on prognosis of malignancies among people living with HIV in Japan.

BACKGROUND: Antiretroviral therapy has reduced the incidence and mortality of AIDS-defining malignancies (ADM); however, non-AIDS-defining malignancies (NADM) are a major cause of death among people living with HIV (PLWH) today. Though current guidelines suggest that PLWH should receive the same treatment as the general population, there are limited studies focused on how HIV status affects the prognosis of cancers. The present study aimed to investigate the characteristics and prognosis of malignant diseases among PLWH in Japan. METHODS: Patients with HIV diagnosed with malignant diseases at our institution between 2011 and 2021 were retrospectively reviewed. RESULTS: There were 205 patients who were diagnosed with malignancies. Of these, 87 (42.4%) were diagnosed with ADM and 118 (57.6%) were diagnosed with NADM. Among 69 patients who received chemotherapy for ADM, 24 (34.8%) developed AIDS-defining opportunistic infections during treatment. In contrast, only one (1.8%) of the 56 patients administered chemotherapy for NADM developed AIDS-defining opportunistic infections. Complications of opportunistic infections at diagnosis of malignancies, low CD4+ T-cell count, positive HIV RNA, and nonadministration of antiretroviral therapy were associated with 5-year overall survival among patients with malignant lymphomas. However, the variables associated with HIV did not affect NADM prognosis. CONCLUSIONS: In this analysis, HIV status had a small impact on the prognosis of malignant diseases in PLWH. Few patients with NADM developed AIDS-defining opportunistic infections after receiving chemotherapy.

Diagnostic delays in breast cancer among young women: An emphasis on healthcare providers.

Despite advances in breast cancer care, breast cancer in young women (BCYW) faces unique challenges, diagnostic delays, and limited awareness in many countries. Here, we discuss the challenges and consequences associated with the delayed diagnosis of BCYW. The consequences of delayed diagnosis in young women - which generally varies among developed, developing, or underdeveloped countries - are severe due to a faster breast tumor growth rate than tumors in older women, also contributing to advanced cancer stages and poorer outcomes. Though there are many underlying reasons for diagnostic delays due to age, the article delves explicitly deep into the diagnostic delay of BCYW, focusing on healthcare providers, potential contributing factors, its consequences, and the urgent need to start minimizing such incidences. The article suggests several strategies to address these issues, including increasing awareness, developing educational programs for healthcare providers to identify signs and symptoms in young women, developing clear diagnostic guidelines, and improving screening strategies.

Reliability and validity of the Japanese version of the Chemotherapy-induced Alopecia Distress Scale.

BACKGROUND: The Chemotherapy-induced Alopecia Distress Scale (CADS) is a patient-reported outcome measure for assessing distress associated with Chemotherapy-induced alopecia (CIA). This study aimed to confirm the psychometric validity of the Japanese version of the CADS (CADS-J). METHODS: A total of 132 patients with breast cancer who developed CIA were asked to complete the CADS-J twice at 2 week intervals to confirm test-retest reliability. The body image domain of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ) breast cancer-specific module, the self-esteem scale from the Rosenberg Self-Esteem Scale, and the emotional domain of the EORTC QLQ Core 30 were used to confirm the convergent validity of the CADS-J. The overall quality of life and physical domains of the EORTC QLQ Core 30 were used to confirm the discriminant validity of the CADS-J. RESULTS: In total, 125 participants provided valid responses. The mean age was 52.2 years. The overall Cronbach's alpha for the CADS-J was 0.903. The intraclass correlation coefficients of the first and second responses were r = 0.874, r = 0.952, r = 0.911, and r = 0.959 for the physical domain, emotional domain, activity domain, and relationship domain, respectively. In terms of convergent validity, the total CADS-J score was moderately correlated with body image (r = - 0.63), self-esteem (r = - 0.48), and the emotional domain (r = - 0.61). Regarding discriminant validity, the total CADS-J score was weakly correlated with the overall quality of life (r = - 0.34) and physical domain (r = - 0.24). CONCLUSIONS: The CADS-J is psychometrically reliable and valid for evaluating the distress caused by CIA. It is expected to be used in daily practice and as an endpoint in various studies.

Severe cytopenia during adjuvant chemotherapy for early breast cancer in a patient with idiopathic CD4+ lymphocytopenia.

Idiopathic CD4+ lymphocytopenia (ICL) is a rare immunodeficiency disorder characterized by decreased CD4+ T-cell counts in the absence of human immunodeficiency virus (HIV) infection. Similar to HIV infection, ICL is commonly associated with acquired immunodeficiency syndrome-defining cancers, such as Kaposi sarcoma, non-Hodgkin lymphoma and cervical cancer; however, the presentation of breast cancer in a patient with ICL is rare. The current study presented the clinical course of a patient with early breast cancer and ICL. Following surgery, the patient underwent adjuvant chemotherapy comprising doxorubicin plus cyclophosphamide, followed by paclitaxel. The patient's immunodeficiency status required the prophylactic administration of clarithromycin, trimethoprim-sulfamethoxazole and valganciclovir. Throughout the course of chemotherapy, the patient experienced severe complications of febrile neutropenia, anemia, neutropenia and thrombocytopenia, and was eventually forced to discontinue anticancer chemotherapy, as the relative dose intensity (RDI) could not be maintained. Similar hematological complications and reduced RDI, leading to worse outcomes, are also common in patients with HIV infection receiving chemotherapy, suggesting that CD4+ T cell-deficient patients are prone to developing cytopenia during chemotherapy. The present study demonstrates the importance of further data accumulation in patients with ICL with cancer and the development of a methodology for maintaining the RDI.

Cancer incidence and type of treatment hospital among children, adolescents, and young adults in Japan, 2016-2018.

Cancer in children, adolescents, and young adults (AYAs) although rare, is the leading disease-specific cause of death in Japan. This study aims to investigate cancer incidence and type of treatment hospital among children and AYAs in Japan. Cancer incidence data (2016-2018) for those aged 0-39 years were obtained from the Japanese population-based National Cancer Registry. Cancer types were classified according to the 2017 update of the International Classification of Childhood Cancer (Third Edition), and AYA Site Recode 2020 Revision. Cases were also categorized into three groups: those treated at core hospitals for pediatric cancer treatment (pediatric cancer hospitals [PCHs]), those treated at designated cancer care hospitals, and those treated at nondesignated hospitals. The age-standardized incidence rate was 166.6 (per million-person years) for children (age 0-14 years) and 579.0 for AYAs (age 15-39 years) (including all cancers and benign or uncertain-behavior central nervous system [CNS] tumors). The type of cancer varied with age: hematological malignancies, blastomas, and CNS tumors were common in children under 10 years, malignant bone tumors and soft tissue sarcomas were relatively common in teenagers, and in young adults over 20 years, carcinomas in thyroid, testis, gastrointestinal, female cervix, and breast were common. The proportion of cases treated at PCHs ranged from 20% to 30% for children, 10% or less for AYAs, and differed according to age group and cancer type. Based on this information, the optimal system of cancer care should be discussed.

Effect of a web-based fertility preservation training program for medical professionals in Japan.

BACKGROUND: Our web-based training program called "Educating Medical Professionals about Reproductive Issues in Cancer Healthcare" aims to help healthcare professionals communicate promptly with patients and survivors who are adolescents and young adults, with information pertinent to reproductive health issues such as the risk of infertility and fertility preservation. METHODS: The study participants were professional healthcare providers, including physicians, nurses, pharmacists, social workers, midwives, psychologists, laboratory technicians, genetic counselors, and dieticians. Pre- and post- and 3-month follow-up tests consisting of 41 questions were administered to measure changes in knowledge and confidence. The participants also received a follow-up survey that covered confidence, communication techniques, and practice habits. A total of 820 healthcare providers participated in this program. RESULTS: The mean total score from the pre-test to the post-test grew significantly (p < 0.01), and participants' self-confidence increased. In addition, there was a change in the behavior of healthcare providers, who began asking about patients' marital status and parity. CONCLUSION: Our web-based fertility preservation training program improved knowledge and self-confidence regarding fertility preservation issues among healthcare providers caring for adolescents and young adult cancer patients and survivors.

Interrupting Endocrine Therapy to Attempt Pregnancy after Breast Cancer.

BACKGROUND: Prospective data on the risk of recurrence among women with hormone receptor-positive early breast cancer who temporarily discontinue endocrine therapy to attempt pregnancy are lacking. METHODS: We conducted a single-group trial in which we evaluated the temporary interruption of adjuvant endocrine therapy to attempt pregnancy in young women with previous breast cancer. Eligible women were 42 years of age or younger; had had stage I, II, or III disease; had received adjuvant endocrine therapy for 18 to 30 months; and desired pregnancy. The primary end point was the number of breast cancer events (defined as local, regional, or distant recurrence of invasive breast cancer or new contralateral invasive breast cancer) during follow-up. The primary analysis was planned to be performed after 1600 patient-years of follow-up. The prespecified safety threshold was the occurrence of 46 breast cancer events during this period. Breast cancer outcomes in this treatment-interruption group were compared with those in an external control cohort consisting of women who would have met the entry criteria for the current trial. RESULTS: Among 516 women, the median age was 37 years, the median time from breast cancer diagnosis to enrollment was 29 months, and 93.4% had stage I or II disease. Among 497 women who were followed for pregnancy status, 368 (74.0%) had at least one pregnancy and 317 (63.8%) had at least one live birth. In total, 365 babies were born. At 1638 patient-years of follow-up (median follow-up, 41 months), 44 patients had a breast cancer event, a result that did not exceed the safety threshold. The 3-year incidence of breast cancer events was 8.9% (95% confidence interval [CI], 6.3 to 11.6) in the treatment-interruption group and 9.2% (95% CI, 7.6 to 10.8) in the control cohort. CONCLUSIONS: Among select women with previous hormone receptor-positive early breast cancer, temporary interruption of endocrine therapy to attempt pregnancy did not confer a greater short-term risk of breast cancer events, including distant recurrence, than that in the external control cohort. Further follow-up is critical to inform longer-term safety. (Funded by ETOP IBCSG Partners Foundation and others; POSITIVE ClinicalTrials.gov number, NCT02308085.).

Distress and impacts on daily life from appearance changes due to cancer treatment: A survey of 1,034 patients in Japan.

This study aimed to clarify the psychosocial difficulties and impacts that cancer patients face from appearance changes, in order to develop a patient support program. An online survey was administered to patients registered with an online survey company who met the eligibility criteria. The study population was randomly selected from gender and cancer types to create a sample that reflected the proportion of cancer incidence rates in Japan as much as possible. Out of a total of 1034 respondents, 601patients (58.1%) experienced appearance change. Symptoms that were reported to have a high distress level and prevalence rate, and that widely required provision of information were such as alopecia (22.2%), edema (19.8%) and eczema (17.8%). Distress levels and personal assistance requirements were high particularly for patients who experienced stoma placement and mastectomy. More than 40% of patients who experienced appearance change had quit or were absent from work or school, and reported that their social activities were negatively affected by the visually notable changes in their appearance. Concerns about "receiving pity from others" or about "the exposure of cancer" due to their appearance change also led patients to reduce outings (ß = 0.32 and ß = 0.31 respectively, p < 0.001) and social interactions with others (ß = 0.34 and ß = 0.36 respectively, p < 0.001) and increased the discord in human relationships (ß = 0.21 and ß = 0.19 respectively, p < 0.001). Results from this study indicate the areas in which more support is required from healthcare professionals, as well as the need for interventions for patient cognition to avoid maladaptive behaviors in cancer patients who experience appearance changes.

Efficacy and safety results by menopausal status in monarchE: adjuvant abemaciclib combined with endocrine therapy in patients with HR+, HER2-, node-positive, high-risk early breast cancer.

Background: Abemaciclib is the first and only cyclin-dependent kinases 4 and 6 inhibitor approved for adjuvant treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), node-positive, and high-risk early breast cancer (EBC), with indications varying by geography. Premenopausal patients with HR+, HER2- tumors may have different tumor biology and treatment response compared to postmenopausal patients. Objectives: We describe the efficacy and safety of abemaciclib plus endocrine therapy (ET) for the large subgroup of premenopausal patients with HR+, HER2- EBC in monarchE. Design: Randomized patients (1:1) received adjuvant ET with or without abemaciclib for 2 years plus at least 3 additional years of ET as clinically indicated. Methods: Patients were stratified by menopausal status (premenopausal versus postmenopausal) at diagnosis. Standard ET (tamoxifen or aromatase inhibitor) with or without gonadotropin-releasing hormone agonist was determined by physician's choice. Invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) by menopausal status were assessed at data cutoff on 1 April 2021 (median follow-up of 27 months). Results: Among randomized patients, 2451 (43.5%) were premenopausal and 3181 (56.4%) were postmenopausal. The choice of ET for premenopausal patients varied considerably between countries. Treatment benefit was consistent across menopausal status, with a numerically greater effect size in premenopausal patients. For premenopausal patients, abemaciclib with ET resulted in a 42.2% and 40.3% reduction in the risk of developing IDFS and DRFS events, respectively. Absolute improvement at 3 years was 5.7% for IDFS and 4.4% for DRFS rates. Safety profile for premenopausal patients was consistent with the overall safety population. Conclusion: Abemaciclib with ET demonstrated clinically meaningful treatment benefit for IDFS and DRFS versus ET alone regardless of menopausal status and first ET, with a numerically greater benefit in the premenopausal compared to the postmenopausal population. Safety data in premenopausal patients are consistent with the overall safety profile of abemaciclib.

Abemaciclib plus endocrine therapy for hormone receptor-positive, HER2-negative, node-positive, high-risk early breast cancer (monarchE): results from a preplanned interim analysis of a randomised, open-label, phase 3 trial.

BACKGROUND: Adjuvant abemaciclib plus endocrine therapy previously showed a significant improvement in invasive disease-free survival and distant relapse-free survival in hormone receptor-positive, human epidermal growth factor receptor 2 (HER2; also known as ERBB2)-negative, node-positive, high-risk, early breast cancer. Here, we report updated results from an interim analysis to assess overall survival as well as invasive disease-free survival and distant relapse-free survival with additional follow-up. METHODS: In monarchE, an open-label, randomised, phase 3 trial, adult patients (aged ≥18 years) who had hormone receptor-positive, HER2-negative, node-positive, early breast cancer at a high risk of recurrence with an Eastern Cooperative Oncology Group performance status of 0 or 1 were recruited from 603 sites including hospitals and academic and community centres in 38 countries. Patients were randomly assigned (1:1) by means of an interactive web-based response system (block size of 4), stratified by previous chemotherapy, menopausal status, and region, to receive standard-of-care endocrine therapy of physician's choice for up to 10 years with or without abemaciclib 150 mg orally twice a day for 2 years (treatment period). All therapies were administered in an open-label manner without masking. High-risk disease was defined as either four or more positive axillary lymph nodes, or between one and three positive axillary lymph nodes and either grade 3 disease or tumour size of 5 cm or larger (cohort 1). A smaller group of patients were enrolled with between one and three positive axillary lymph nodes and Ki-67 of at least 20% as an additional risk feature (cohort 2). This was a prespecified overall survival interim analysis planned to occur 2 years after the primary outcome analysis for invasive disease-free survival. Efficacy was assessed in the intention-to-treat population. Safety was assessed in all treated patients. The study is registered with ClinicalTrials.gov, NCT03155997, and is ongoing. FINDINGS: Between July 17, 2017, and Aug 12, 2019, 5637 patients were randomly assigned (5601 [99·4%] were women and 36 [0·6%] were men). 2808 were assigned to receive abemaciclib plus endocrine therapy and 2829 were assigned to receive endocrine therapy alone. At a median follow-up of 42 months (IQR 37-47), median invasive disease-free survival was not reached in either group and the invasive disease-free survival benefit previously reported was sustained: HR 0·664 (95% CI 0·578-0·762, nominal p<0·0001). At 4 years, the absolute difference in invasive disease-free survival between the groups was 6·4% (85·8% [95% CI 84·2-87·3] in the abemaciclib plus endocrine therapy group vs 79·4% [77·5-81·1] in the endocrine therapy alone group). 157 (5·6%) of 2808 patients in the abemaciclib plus endocrine therapy group died compared with 173 (6·1%) of 2829 patients in the endocrine therapy alone group (HR 0·929, 95% CI 0·748-1·153; p=0·50). The most common grade 3-4 adverse events were neutropenia (in 548 [19·6%] of 2791 patients receiving abemaciclib plus endocrine therapy vs 24 [0·9%] of 2800 patients in the endocrine therapy alone group), leukopenia (318 [11·4%] vs 11 [0·4%]), and diarrhoea (218 [7·8%] vs six [0·2%]). Serious adverse events occurred in 433 (15·5%) of 2791 patients receiving abemaciclib plus endocrine therapy versus 256 (9·1%) of 2800 receiving endocrine therapy. There were two treatment-related deaths in the abemaciclib plus endocrine therapy group (diarrhoea and pneumonitis) and none in the endocrine therapy alone group. INTERPRETATION: Adjuvant abemaciclib reduces the risk of recurrence. The benefit is sustained beyond the completion of treatment with an absolute increase at 4 years, further supporting the use of abemaciclib in patients with high-risk hormone receptor-positive, HER2-negative early breast cancer. Further follow-up is needed to establish whether overall survival can be improved with abemaciclib plus endocrine therapy in these patients. FUNDING: Eli Lilly.

Current Status and Issues of the Japan Oncofertility Registry.

Purpose: Fertility preservation (FP) is becoming increasingly common among child, adolescent, and young-adult (CAYA) patients with cancer. However, Japan has long lacked definite estimates of utilization rates for FP services among CAYA patients with cancer, and little is known about disease/FP outcomes among users. Therefore, the Japan Society for Fertility Preservation (JSFP) launched the Japan Oncofertility Registry (JOFR) in 2018 and started the online registration of information regarding primary disease, FP, and data on prognosis and pregnancy outcomes. This study reports the analytical results of FP data registered in the JOFR as of 2021. Methods: Data about patients' primary disease(s), treatment courses, cancer and pregnancy outcomes, and specific procedures were extracted from the JOFR and analyzed. Results: In 2021, 1244 patients received counseling or treatment related to FP (540 males, 704 females). While the numbers of males in each age group were approximately equal, most females were aged between 31 and 40 years. In total, 490 male and 540 female patients underwent FP procedures. Leukemia, testicular cancer, and malignant lymphoma accounted for the majority of male cases seeking treatment, whereas breast cancer was the primary disease in two-thirds of the females. Since 1999, 395 patients have accumulatively experienced subsequent pregnancy. Conclusions: As of January 2022, >7000 cases from >100 fertility facilities have been registered in the JOFR. In the future, maintaining JOFR to disseminate information on cancer prognoses, pregnancy rates, and other oncofertility outcomes is expected to drive further expansion of oncofertility services in Japan.

Development of an educational program for healthcare professionals who provide appearance care for patients with cancer: Feasibility study of an e-learning program.

This study aimed to evaluate the feasibility and utility of an e-learning training program to improve healthcare professionals' knowledge about providing appearance care to patients with cancer. Healthcare professionals who provide appearance support were invited to participate voluntarily and complete a survey before and after the program. Participation request letters were distributed to 133 individuals, including 75 from four facilities invited via professional connections, and agreed to participate in the study and 58 participated in the National Cancer Center's appearance care training and indicated an interest in participating in the study. The 100 participants (75.2%) included 96 females, with an average age of 40.5 years. The participants reported high levels of satisfaction with the program, where more than 90% responded "satisfied" or "somewhat satisfied" and eager to use the content they learned in the program when they returned to their workplaces. However, the participants identified several barriers to applying their newly acquired knowledge including lack of knowledge (about 80%). Participant knowledge scores about appearance support were significantly higher after program participation. The survey results indicated the high feasibility of the e-learning program through improved knowledge about appearance care and high satisfaction with the program. The program needs further improvements for its practical utility.

Response to lenvatinib and pembrolizumab combination therapy in pembrolizumab-pretreated relapsed endometrial cancer.

Uterine endometrial cancer is one of the most common gynecological malignancies worldwide. With relatively few options for late-line therapies for advanced or relapsed endometrial cancer, the use of pretreated therapies may broaden the choice of treatments. Here, we report a case of recurrent microsatellite instability-high endometrial cancer that acquired resistance to pembrolizumab but favorably responded to the lenvatinib and pembrolizumab combination therapy. Lenvatinib combined with pembrolizumab may be effective against endometrial cancer resistant to pembrolizumab monotherapy, encouraging its use regardless of prior administration of immune checkpoint inhibitors. Further investigation on the lenvatinib and pembrolizumab combination therapy and the mechanism underlying its anticancer effect may provide new insights into cancer immunotherapy and tumor microenvironments.

Cardiotoxicity of adjuvant chemotherapy with trastuzumab: a Japanese claim-based data analysis.

OBJECTIVE: Adjuvant chemotherapy with trastuzumab improves the postoperative life expectancy of women with early-stage breast cancer. Although trastuzumab is reportedly cardiotoxic, quantification based on real-world evidence is lacking. Therefore, in this study, we aimed to analyse trastuzumab cardiotoxicity using a nationwide claim-based database. METHODS: In this retrospective study, we used data from a nationwide claims database (Japan Medical Data Center, Tokyo, Japan) under the universal healthcare system. Women with breast cancer who underwent initial surgery were included. Patients with recurrent or advanced-stage breast cancer, with a history of heart failure, receiving neoadjuvant chemotherapy or a preoperative history of less than 6 months were excluded. Propensity score (PS) was calculated using logistic regression based on age, cardiovascular risk factors, radiotherapy and concomitant anthracyclines (AC). RESULTS: We identified 12 060 eligible patients (mean age 50.8±8.56 years) between January 2010 and December 2019. After 1:2 PS matching (trastuzumab users, TZ, n=1005; non-users, NT, n=2010), Cox proportional hazards model analysis showed that the rate of heart failure development within 18 months postoperative was significantly higher in the TZ group than in the NT group (adjusted HR 2.28, 95% CI 1.38 to 3.77). Baseline cardiac evaluation in the combined AC/TZ cases was 27.2% preoperative, 66.0% pre-AC and 86.6% pre-TZ, respectively. CONCLUSION: Trastuzumab cardiotoxicity remained relevant in the claim-based analysis adjusted for AC effects. Further collaborative studies in cardio-oncology with real-world data are warranted to improve the rate of baseline cardiovascular risk assessment in patients with cancer scheduled for cardiotoxic cancer treatment.

Treatment With Adjuvant Abemaciclib Plus Endocrine Therapy in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy: A Prespecified Analysis of the monarchE Randomized Clinical Trial.

Importance: Patients selected to receive neoadjuvant chemotherapy (NAC) are usually those at higher risk of relapse, and there is a need to find better therapeutic options for these patients. Objective: To determine the efficacy and safety outcomes for patients with hormone receptor (HR)-positive, ERBB2 (formerly HER2)-, high-risk early breast cancer enrolled in the randomized clinical trial monarchE who received NAC. Design, Setting, and Participants: The monarchE randomized clinical trial was a multicenter, phase 3, open-label study that evaluated adjuvant treatment with abemaciclib plus endocrine therapy (ET) compared with ET alone in patients with HR+, ERBB2-, and node-positive early breast cancer who were at high risk of recurrence. Patients were recruited between July 2017 and August 2019 from 603 sites in 38 countries. This subgroup analysis was performed with primary outcome data, with a cutoff date of July 8, 2020. Intervention: Enrolled patients were randomized (1:1) to receive standard of care ET for at least 5 years with or without treatment with abemaciclib (150 mg, twice daily) for 2 years (treatment period) or until criteria were met for discontinuation. Main Outcomes and Measures: Prior chemotherapy (NAC vs adjuvant vs none) was a stratification factor in monarchE, and and a prespecified exploratory analysis included outcomes in patients who received NAC. The data presented in this article are from the primary outcome analysis (395 invasive disease-free survival [IDFS] events; cutoff date, July 8, 2020; median follow-up 19 months [IQR, 15.6-23.9 months]). Invasive disease-free survival (the primary end point of monarchE) and distant relapse-free survival (DRFS) were evaluated using the Cox proportional hazard model and Kaplan-Meier method. Results: Of the 5637 patients (mean [SD] age, 49.9 [10.6] years; 2046 women [99.5%]; 462 Asian [22.8%], 54 Black [2.7%], and 1473 White participants [70.8%]) enrolled in monarchE, 2056 (37%) received treatment with NAC. In this subgroup, treatment with abemaciclib and ET demonstrated clinically meaningful benefit in IDFS (hazard ratio, 0.61; 95% CI, 0.47-0.80) and DRFS (hazard ratio, 0.61; 95% CI, 0.46-0.81), which corresponded with an absolute improvement of 6.6% in 2-year IDFS rates and 6.7% in 2-year DRFS rates. A consistent treatment benefit was observed across subgroups of pathological breast tumor size or number of positive lymph nodes at surgery. Conclusions and Relevance: In the randomized clinical trial monarchE, treatment with adjuvant abemaciclib combined with ET demonstrated a clinically meaningful improvement in IDFS and DRFS for patients with HR+, ERBB2-, node-positive, high-risk early breast cancer who received NAC before trial enrollment. Trial Registration: ClinicalTrials.gov Identifier: NCT03155997.