The Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer, 2022 Edition: changes from the 2018 edition and general statements on breast cancer treatment.

The Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer, 2022 Edition was published in June 2022. The guidelines were prepared while conforming as much as possible to the "Minds Manual for Guideline Development 2020 ver. 3.0." edited by the Minds Manual Development Committee of the Japan Council for Quality Health Care in 2021. In addition, a survey of Japanese Breast Cancer Society members on the 2018 edition of the guidelines was conducted from February 19 to March 4, 2021. Based on the responses from over 600 members, original innovations were made to make the guidelines more user-friendly. The 2018 edition of the guidelines was developed to provide support tools for physicians and patients to utilize shared decision-making. The 2022 guidelines consist of two volumes: (1) an "Epidemiology and Diagnosis" section covering "Screening and Diagnosis", "Radiological diagnosis", and "Pathological diagnosis", and (2) a "Treatment" section covering "Surgical therapy", "Radiation therapy", and "Systemic therapy". We believe that this concise summary of the guidelines will be useful to physicians and researchers in Japan and overseas.

Correlation between postoperative treatment selection and prognosis determined using the Oncotype DX® test data: a retrospective multicenter study in Japan.

PURPOSE: Oncotype DX® is a frequently used multigene assay for hormone receptor-positive breast cancers. However, limited evidence is available regarding its application in Japan owing to the lack of insurance coverage. Therefore, we conducted this large-scale, retrospective study by collecting data from nine Japanese institutes and assessed postoperative treatment choice and prognosis by using Oncotype DX®. METHODS: Six hundred thirty-two patients who underwent breast surgery and whose recurrence score (RS) data were available were included. They were divided into RS 0-25 and RS ≥ 26 groups. The groups were compared in terms of clinicopathological factors, treatment options, and prognosis. RESULTS: After the median follow-up period of 10.1 years, the disease-free survival (DFS) rates were significantly better in the RS 0-25 group (p = 0.02). Per the recurrent event type, there was no significant intergroup difference in locoregional recurrence (p = 0.139). However, a trend toward better distant DFS was observed in the RS 0-25 group (p = 0.08). Overall survival was also significantly better in this group (p = 0.027). Considering chemotherapy use, DFS worsened among chemotherapy-treated patients with an RS of 0-25 and those with an RS ≥ 26 who did not receive chemotherapy (p < 0.001). Seven (1.35%) chemotherapy-treated patients with an RS of 0-25 showed disease recurrence. CONCLUSIONS: This study presents the largest database-derived prognostic data in Japanese patients, utilizing the Oncotype DX® treatment selection. Further studies are needed to determine the impact on treatment choice, considering the clinical risk, and the need for additional postoperative treatment.

The Japanese Breast Cancer Society Clinical Practice Guidelines for surgical treatment of breast cancer, 2022 edition.

The 2022 revision of the Japanese Breast Cancer Society (JBCS) Clinical Practice Guidelines for surgical treatment of breast cancer was updated following a systematic review of the literature using the Medical Information Network Distribution Service (MINDS) procedure, which focuses on the balance of benefits and harms for various clinical questions (CQs). Experts in surgery designated by the JBCS addressed five areas: breast surgery, axillary surgery, breast reconstruction, surgical treatment for recurrent and metastatic breast cancer, and other related topics. The revision of the guidelines encompassed 4 CQs, 7 background questions (BQs), and 14 future research questions (FRQs). A significant revision in the 2022 edition pertained to axillary management after neoadjuvant chemotherapy in CQ2. The primary aim of the 2022 JBCS Clinical Practice Guidelines is to provide evidence-based recommendations to empower patients and healthcare professionals in making informed decisions regarding surgical treatment for breast cancer.

Phase III study of long-term prognosis of estrogen receptor-positive early breast cancer treated with neoadjuvant endocrine therapy with/without adjuvant chemotherapy.

PURPOSE: Neoadjuvant endocrine therapy (NET) is a treatment option for estrogen receptor-positive (ER+) postmenopausal early breast cancer (EBC). This phase III trial evaluated the prognosis of EBC patients treated with/without chemotherapy (CT) following NET. METHODS: ER+/HER2-, T1c-2, and clinically node-negative EBC patients were enrolled in 2008-2013 and treated with endocrine therapy (ET) in weeks 24-28. All patients, excluding those with progressive disease (PD) during NET or ≥ 4 positive lymph nodes after surgery, were randomized to ET for 4.5-5 years with/without CT. The primary endpoint was disease-free survival (DFS). Secondary endpoints included distant DFS (DDFS), overall survival (OS), and DFS/DDFS/OS according to clinical response to NET. RESULTS: Of 904 patients, 669 were randomized to CT+ET (n = 333) or ET alone (n = 336). The median follow-up was 7.8 years. DFS (CT+ET, 47 events; ET alone, 70 events) and DDFS did not reach the planned numbers of events. Eight-year DFS/DDFS rates were 86%/93% and 83%/92%, respectively. DFS was significantly better in CT+ET than ET alone in subgroups aged < 60 years (P = 0.016), T2 (P = 0.013), or Ki67 > 20% (P = 0.026). Progesterone receptor and histological grade were predictive markers for clinical responses to NET. CONCLUSION: NET may be used as standard treatment for patients with ER+EBC. Although it is difficult to decide whether to administer adjuvant CT based solely on the effect of NET, the response to NET may help to inform this decision. TRIAL REGISTRATION: This study was registered at the UMIN Clinical Trials Registry under UMIN000001090 (registered 20 March 2008).

Childbirth after perioperative systemic therapy in patients with breast cancer: a retrospective single institutional study in Japan.

BACKGROUND: The number of breast cancer patients of childbearing age has been increasing. Therefore, we investigated the characteristics and the childbearing status of the patients who received systemic therapy for breast cancer during their childbearing age to better understand the clinical impact of childbirth. METHODS: Female patients with breast cancer younger than 40 years old who underwent surgery and received perioperative systemic therapy from 2007 to 2014 were included in this study. We compared the characteristics of patients with and without childbirth after treatment. RESULT: Of 590 patients, 26 delivered a child, and 355 did not bear a child during the median observation period of 8.1 years, whilst 209 had unknown childbirth data. The childbirth group had a lower mean age at surgery (32.2 vs. 35.1, P < 0.001). The proportion of patients who desired childbirth and used assisted reproductive technology was significantly higher in the childbirth group (65.4 vs. 23.9% and 45.2 vs. 5.1%, respectively, P < 0.001). The patients in the childbirth group had significantly less advanced disease (P = 0.002). In the childbirth group, the age at childbirth was significantly older in patients who received combined endocrine therapy and chemotherapy (40.8 years) than in patients who received either alone (endocrine therapy: 36.9 years, chemotherapy: 36.7 years, P = 0.04). However, survival was not different between those with and without childbirth. CONCLUSION: It is critical to recognize the desire for childbirth in patients with breast cancer who are receiving systemic therapy and to provide them with necessary fertility information before treatment to support their decision-making.

Clinical significance of the neutrophil-to-lymphocyte ratio in oligometastatic breast cancer.

PURPOSE: This study investigated the clinical impact of pretreatment neutrophil-to-lymphocyte ratio (NLR) on survival in patients with oligometastatic breast cancer. PATIENTS AND METHODS: We collected data from 397 patients who underwent primary breast surgery from 2004 to 2015 and developed recurrence during the follow-up. We reviewed the images and clinical information and defined OMD according to the European Society for Medical Oncology advanced breast cancer guidelines. The NLR was calculated using pretreatment data of primary breast cancer. The cutoff value of the NLR was determined by receiver operating characteristic curve with Youden Index. RESULTS: Among 397 patients, 131 had OMD at recurrence. The low-NLR group included patients of significantly older age at primary cancer than those in the high-NLR group. A low NLR indicated a better overall survival (p = 0.023) after adjusting for relevant factors, including estrogen receptor status, surgical resection of metastatic disease, metastatic organ number, disease-free interval, and liver metastasis than did the high-NLR group. We developed prognostic models for OMD using six independent prognostic factors, including the NLR. The number of factors was associated with overall survival; patients with all six favorable factors showed a good overall survival of 90.9% at 8 years and those with four or more factors showed 70.4%. CONCLUSIONS: The NLR was an independent prognostic factor for overall survival in OMD. The number of favorable prognostic factors was associated with overall survival. A prognostic model, including the NLR, will help identify patients with a favorable prognosis.

Characteristics, treatment trends, and long-term outcomes of Japanese patients with pregnancy-associated breast cancer (PABC).

PURPOSE: To clarify the characteristics, treatment trends, and long-term outcomes of patients with pregnancy-associated breast cancer (PABC). METHODS: PABC includes breast cancer diagnosed during pregnancy (PBC) and breast cancer diagnosed within 1 year after childbirth or during lactation (LBC). We compared clinical characteristics of 126 patients with LBC and 49 patients with PBC who underwent surgery at our hospital from 1946 to 2018. Survival was compared between patients with LBC and those with PBC in terms of breast cancer-specific disease-free survival (BC-DFS) and overall survival (OS). RESULTS: Patients with LBC were more likely to have family history, lymph node metastasis, lymphatic invasion, and to receive chemotherapy than patients with PBC. Patients with LBC showed poorer BS-DFS and OS than patients with PBC. Among patients with LBC, those treated after 2005 were older at surgery, had a smaller tumor size, received more systemic therapy, and had a more favorable prognosis than patients treated before 2004. Family history, breast cancer within 1 year after childbirth, and surgery before 2004 as well as cStage, lymph node metastasis, and lymphatic invasion were significantly associated with poor prognosis in patients with LBC. In the multivariate analysis for BC-DFS and OS among patients with PABC, LBC vs PBC did not remain as an independent prognostic factor while cStage remained. CONCLUSION: Patients with LBC had a poorer prognosis than those with PBC, most likely due to disease progression rather than biological characteristics. Early detection and optimization of systemic treatments are critical for improving the outcomes of patients with LBC.

Relation of Maximum Lifetime Body Mass Index with Age at Hemodialysis Initiation and Vascular Complications in Japan.

OBJECTIVE: The aim of this study was to investigate the association of the maximum lifetime body mass index (max BMI) with hemodialysis initiation and comorbidities in Japanese hemodialysis patients. METHODS: In a retrospective cross-sectional study on 724 hemodialysis patients, max BMI, age at hemodialysis initiation, and comorbidities including sleep apnea syndrome, cerebro-cardiovascular diseases, and proliferative diabetic retinopathy (PDR) were analyzed. Early hemodialysis initiation was defined as age <50 years. RESULT: Diabetes patients showed a higher max BMI and prevalence of atherosclerotic diseases than nondiabetes patients, despite almost the same age at hemodialysis initiation. Patients with early hemodialysis initiation showed higher male ratio, prevalence of PDR, and max BMI than those with later initiation, despite almost equal prevalence of diabetes. Receiver-operating characteristic curve analysis determined a max BMI of 28.4 kg/m2 as a reliable cutoff value for predicting early hemodialysis initiation, and this parameter was identified as an independent predictor of early hemodialysis initiation using bivariate logistic regression analysis. Vitrectomy for PDR also tended to contribute independently to early hemodialysis initiation. CONCLUSION: A high max BMI contributed to early hemodialysis initiation independent of diabetes. Furthermore, PDR was associated with a high max BMI and early hemodialysis initiation. These results suggest that weight reduction in young chronic kidney disease patients with obesity may prevent hemodialysis and blindness.

Assessment of axillary node status by ultrasound after neoadjuvant chemotherapy in patients with clinically node-positive breast cancer according to breast cancer subtype.

The use of sentinel node biopsy (SNB) following neoadjuvant chemotherapy (NAC) for patients with cN1 breast cancer is controversial. Improvements of negative predictive value (NPV) by axillary ultrasound (AUS), which corresponds to the accurate prediction rate of node-negative status after NAC, would lead to decreased FNR of SNB following NAC. In this study, we retrospectively investigated the accurate prediction rate of NPV by AUS after NAC in patients with cytologically node-positive breast cancer treated between January 2012 and December 2016. Of 279 eligible patients, the NPV was 49.2% in all patients, but varied significantly by tumor subtype (p < 0.001) and tumor response determined by magnetic resonance imaging (MRI) (p = 0.0003). Of the 23 patients with clinically node negative (ycN0) by AUS and clinical complete response in primary lesion by MRI, the NPV was 100% in patients with HR±/HER2+ or HR-/HER2- breast cancer. In conclusion, regarding FNR reduction post-NAC, it will be of clinical value to take tumor subtype and primary tumor response using MRI into account to identify patients for SNB after NAC.

Local management after neoadjuvant treatment for breast cancer.

Neoadjuvant chemotherapy (NAC) was originally used in patients with locally advanced breast cancer. Then, it is used in operable breast cancer to downstage the primary breast cancer and axillary lymph nodes metastasis, result in improving the cosmetic outcome and decreasing surgical morbidity. However, it is sometimes difficult to assess the extent of residual disease after NAC, as the NAC reduces the lesion and obscure the original images both breast and axilla. Thus, detailed assessment of primary breast cancer and axillary lymph nodes metastasis are required from the time of before NAC until the time of surgery. These assessments include the accurate location, the extent of intraductal component around primary tumor and the axillary nodal status. Multimodality imaging with intervention for cytopathology can help to delineate the size and location of breast cancer and lymph node metastasis and predict the residual tumor burden in primary breast cancer and involved axillary nodes. In the future, with development of new targeted therapy, technologies in medical imaging diagnosis and ongoing trial data will provide further individualized treatment option for patients with breast cancer. This article reviews the current evidence and management recommendations for optimal surgical treatment in this setting.

Usefulness of second-look ultrasonography using anatomical breast structures as indicators for magnetic resonance imaging-detected breast abnormalities.

BACKGROUND: Second-look ultrasonography (US) is commonly performed for breast lesions detected using magnetic resonance imaging (MRI), but the identification rate of these lesions remains low. We investigated if US methods using anatomical breast structures can improve the lesion identification rate of MR-detected lesions and evaluated the diagnostic performance of fine-needle aspiration cytology (FNAC) of the second-look US using the above-mentioned method. METHODS: We retrospectively assessed 235 breast lesions (hereinafter, "targets") subjected to second-look US following MRI between January 2013 and September 2015. US was employed using the conventional methods, and this assessment measured the positional relationships of lesions with regard to surrounding anatomical breast structures (glandular pattern, Cooper's ligaments, adipose morphology, and vascular routes). Associations were assessed among the following variables: the MRI findings, target size, identification rate, and main US indicators that led to identifying the target; FNAC results and MRI findings; MRI findings and histopathological findings; and FNAC results and histopathological findings. Moreover, the sensitivity and specificity of FNAC were determined. RESULTS: The identification rate was 99%. The main US indicators leading to identification were a glandular pattern (28-30% of lesions) and other breast structures (~ 25% of lesions). FNAC was performed for 232 targets with the following results: sensitivity of 85.7%, specificity of 91.6%, PPV of 94.1%, NPV of 92.9%, false-negative rate of 14.3%, false-positive rate of 2.1%, and accuracy of 89.7%. CONCLUSIONS: Second-look US using anatomical breast structures as indicators and US-guided FNAC are useful for refining the diagnosis of suspicious breast lesions detected using MRI.

The Japanese Breast Cancer Society clinical practice guidelines for surgical treatment of breast cancer, 2018 edition.

We have prepared the Japanese Breast Cancer Society clinical practice guidelines (CPGs) for surgical treatment of breast cancer, 2018 update after a systematic review (SR) of the literature based upon the Medical Information Network Distribution Service (Minds) procedure. The CPG committee for surgical treatment of breast cancer, composed of breast surgeons and plastic surgeons treating breast cancer, has developed the CPGs. Eight clinical questions (CQs) were selected and divided roughly into the following five categories: (1) breast surgery in initial therapy (CQs 1-3); (2) axillary surgery in initial therapy (CQs 4-5); (3) breast reconstruction in initial therapy (CQ 6); (4) surgical treatment for recurrent and metastatic breast cancer (CQs 7-8); and (5) others. Recommendations for these CQs were decided by the GRADE grid method. In addition, 4 outlines, 14 background questions (BQs), and 12 future research questions (FQs) were also selected. Statements for these BQs and FQs are provided. We developed the updated CPGs for surgical treatment of breast cancer, 2018, which include 8 CQs and recommendations. As a decision-making tool for the understanding and treatment of breast cancer, these guidelines will help surgical oncologists dealing with breast cancer, medical staff, and patients, along with their family members.

Altered lymphatic drainage patterns in re-operative sentinel lymph node biopsy for ipsilateral breast tumor recurrence.

BACKGROUND: This study aimed to evaluate the impact of previous local treatment on lymphatic drainage patterns in ipsilateral breast tumor recurrence (IBTR) based on our data on re-operative sentinel lymph node biopsy (re-SLNB) for IBTR. METHODS: Between April 2005 and December 2016, re-SLNB using lymphoscintigraphy with Tc-99 m phytate was performed in 136 patients with cN0 IBTR. Patients were categorized into two groups: the AX group included 55 patients with previous axillary lymph node dissection; the non-AX group included 69 patients with previous SLNB and 12 patients with no axillary surgery. The whole breast irradiation (RT) after initial surgery had performed in 17 patients in the AX group and 27 patients in the non-AX group. RESULTS: Lymphatic drainage was visualized in 80% of the AX group and 95% of the non-AX group (P < 0.01). The visualization rate of lymphatic drainage was associated with the number of removed lymph nodes in prior surgery. In the non-AX group, lymphatic drainage was visualized in 96% of patients without RT and 93% with RT. Lymphatic drainage was observed at the ipsilateral axilla in 98% of patients without RT and in 64% with RT (P < 0.0001). Aberrant drainage was significantly more common in patients with RT than without RT (60% vs. 19%, P < 0.001); it was observed mostly to the contralateral axilla (52% vs. 2%, P < 0.0001). In the AX group, patients with previous RT showed decreased lymphatic drainage to the ipsilateral axilla compared to those without RT (29% vs. 63%, P < 0.05) and increased aberrant drainage to the contralateral axilla (64% vs. 5%, P < 0.0001). CONCLUSION: Lymphatic drainage patterns altered in re-SLNB in patients with IBTR and previous ALND and RT were associated with alterations in lymphatic drainage patterns.

National trends of synchronous bilateral breast cancer incidence in the United States.

PURPOSE: Increase in breast cancer survivorship, advancements in diagnostic imaging and standardization of contralateral breast screening before breast cancer surgery have resulted in increased detection of contralateral breast cancer (CBC). The aim of this study was to assess national trends of synchronous bilateral breast cancer (sBBC) and metachronous bilateral breast cancer (mBBC) incidence in newly diagnosed breast cancer patients. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database (1973-2014) was used to identify 11,177 women diagnosed with CBC. CBC was classified as sBBC when primary breast cancer in both breasts is diagnosed in the same year, or as mBBC, when diagnosed more than one year from primary breast cancer. Temporal trends in sBBC incidence were then evaluated using the Cochran-Armitage test for trend. RESULTS: Of the 11,177 women diagnosed with CBC, 4228 (38%) had sBBC and 6949 (62%) had mBBC. The incidence of sBBC increased significantly from 1.4% in 1975 to 2.9% in 2014 (p < 0.001). sBBC was more likely to be diagnosed as early stage in recent years (78% in 1975 vs. 90% in 2014 [p < 0.001]), and 69% of patients were treated with mastectomy in 2014. CONCLUSION: The number of sBBC has increased, and contralateral tumors are more likely to be detected at an early stage with the first primary breast cancer. Despite the early stage findings, most were treated with mastectomy. Further studies are needed to define the best therapy for patients with contralateral disease and optimal surveillance and detection methods.

Survival Outcomes for Patients With Clinical Complete Response After Neoadjuvant Chemotherapy: Is Omitting Surgery an Option?

BACKGROUND: Surgery after neoadjuvant chemotherapy (NCT) is an accepted treatment approach for locally advanced and some early-stage breast cancers, even for patients with a clinical complete response (cCR) after NCT. This study sought to evaluate the survival outcomes for patients with cCR to NCT who did not undergo surgery. METHODS: The National Cancer Data Base (NCDB) was used to identify 93,417 women age 18 years or older with a diagnosis of invasive breast cancer who received NCT between 2010 and 2015. The study identified 350 women with cT1-4, N0-3, and M0 tumors who underwent NCT and did not have surgery. A matched surgical cohort was extracted from the NCDB, and overall survival (OS) was compared between the surgical and nonsurgical patients after NCT. RESULTS: Of the 350 NCT patients who did not undergo surgery, 45 (12.9%) had cCR, 51 (14.6%) had a partial response, 241 (68.9%) had a response but whether complete or partial was not recorded, and 13 (3.7%) had no response/progression. The 5-year OS was better in the cCR group than in the no-cCR group (96.8% vs 69.8%; p = 0.004). A 5-year OS analysis of the cCR patients without surgery (n = 45; median follow-up period, 37 months) compared with the patients with a pathologic complete response who underwent surgery (n = 3938; median follow-up period, 43 months) showed no statistically significant difference (96.8% vs 92.5%, respectively; p = 0.15). CONCLUSION: This retrospective cohort study demonstrated that active surveillance or de-escalation therapy may be an option for patients who achieve cCR. Prospective studies are underway to determine whether a subgroup of patients may forgo surgery in the setting of cCR after NCT.

Validation of the 21-gene test as a predictor of clinical response to neoadjuvant hormonal therapy for ER+, HER2-negative breast cancer: the TransNEOS study.

PURPOSE: The Recurrence Score test is validated to predict benefit of adjuvant chemotherapy. TransNEOS, a translational study of New Primary Endocrine-therapy Origination Study (NEOS), evaluated whether Recurrence Score results can predict clinical response to neoadjuvant letrozole. METHODS: NEOS is a phase 3 clinical trial of hormonal therapy ± adjuvant chemotherapy for postmenopausal patients with ER+, HER2-negative, clinically node-negative breast cancer, after six months of neoadjuvant letrozole and breast surgery. TransNEOS patients had tumors ≥ 2 cm and archived core-biopsy samples taken before neoadjuvant letrozole and subsequently sent for Recurrence Score testing. The primary endpoint was to evaluate clinical (complete or partial) response to neoadjuvant letrozole for RS < 18 versus RS ≥ 31. Secondary endpoints included evaluation of clinical response and rate of breast-conserving surgery (BCS) by continuous Recurrence Score result, ESR1 and PGR single-gene scores, and ER gene-group score. RESULTS: Of 295 TransNEOS patients (median age 63 years; median tumor size 25 mm; 66% grade 1), 53.2% had RS < 18, 28.5% had RS18-30, and 18.3% had RS ≥ 31. Clinical response rates were 54% (RS < 18), 42% (RS18-30), and 22% (RS ≥ 31). A higher proportion of patients with RS < 18 had clinical responses (p < 0.001 vs. RS ≥ 31). In multivariable analyses, continuous Recurrence Score result (p < 0.001), ESR1 score (p = 0.049), PGR score (p < 0.001), and ER gene-group score (p < 0.001) were associated with clinical response. Recurrence Score group was significantly associated with rate of BCS after neoadjuvant treatment (RS < 18 vs. RS ≥ 31, p = 0.010). CONCLUSION: The Recurrence Score test is validated to predict clinical response to neoadjuvant letrozole in postmenopausal patients with ER+, HER2-negative, clinically node-negative breast cancer.

Local Introgression of Mitochondrial DNA in Eight-Barbel Loaches of the Genus Lefua (Balitoridae, Cypriniformes).

The evolutionary history of eight-barbel loaches of the genus Lefua was investigated to resolve the faunal formation and evolutionary history of Japanese and East Asian freshwater fishes. In the present study, we found that seven Lefua specimens obtained from western Japan could not be assigned genetically to any population recognized so far, although they were morphologically and ecologically indistinguishable from Lefua sp 1. We tentatively designated the specimens as the Nihonkai population. Sequencing of the mitochondrial D-loop region showed that five specimens of the Nihonkai population were allied with the Kinki and Tokai populations of L. echigonia and other two with Lefua sp. 2, indicating a discrepancy between morphological-ecological and genetic traits. In order to determine whether the population experienced parallel evolution or introgression of mitochondrial DNA, we sequenced the nuclear ribosomal S7 subunit, and demonstrated that the Nihonkai population is included within Lefua sp. 1. These results indicate that the Nihonkai population can be identified as Lefua sp. 1, possessing introgressive mitochondrial DNA, and suggest that the evolutionary history and faunal formation of Japanese and East Asian freshwater fishes are more complicated than previously thought.