Search

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., (© 2024. The Author(s).)

The Japanese Breast Cancer Society Clinical Practice Guidelines for Epidemiology and Prevention of Breast Cancer, 2022 Edition., (© 2023. The Author(s).)

Background: Programmed death-ligand 1 (PD-L1) plays important roles in the evasion of antitumor immunity. Because we observed the localization of PD-L1-positive (PD-L1 + ) cells in the marginal region of triple-negative breast cancer (TNBC) specimens, we hypothesized that the marginal microenvironment of TNBC would involve the induction of PD-L1 + cells., Methods: One hundred and one TNBC surgical specimens were examined. We performed immunohistochemical (IHC) studies of PD-L1, CD68, CD8, and pan-cytokeratin in these specimens. We analyzed the localization of IHC-positive cells and the distance between these cells by histological spatial analysis., Results: In 30.7% of TNBC specimens, PD-L1 + cells were located in the marginal region. Approximately three PD-L1 + cells accumulated around a single TNBC cell. Most PD-L1 + cells were located within 50 μm of TNBC cells. PD-L1 + cells were indicated to interact with TNBC cells in the marginal region. PD-L1 + CD68 + cells were located in the marginal region, while CD68 + macrophages (MΦs) were observed either in the marginal region or the core region. PD-L1 expression in MΦs was induced in the marginal region. The colocalization of CD8 + T cells in the marginal region indicates that PD-L1 expression in MΦs would be induced by interaction with CD8 + T cells. Because CD8 + T cells are positive for CCL2, CCL2 may induce PD-L1 expression in MΦs., Conclusion: At the marginal microenvironment of TNBC, PD-L1 expression would be induced in MΦs by interaction with CD8 + T cells through CCL2. The interaction between PD-L1 + MΦs and TNBC cells would facilitate the growth of TNBC under antitumor immunity. These interactions would be potential targets for restoring antitumor immunity and suppressing TNBC progression., (© 2023. The Author(s).)

Alcohol consumption is internationally recognized as one of the compelling risk factors for breast cancer, but it does not necessarily correlate with the prognosis of breast cancer patients. Alcohol consumption in breast cancer patients was addressed in the 2022 Breast Cancer Clinical Practice Guidelines. A systematic review and meta-analysis of epidemiological studies on alcohol consumption and breast cancer recurrence, breast cancer-related mortality, all-cause mortality, and cardiovascular disease mortality in breast cancer patients was performed. The PubMed, Cochrane Library, and Ichushi-Web databases were searched for relevant publications reporting cohort or case-control studies published until March 2021. A total of 33 studies (32 cohort studies and 1 case-control study) met the eligibility criteria; 4638 cases of recurrence, 12,209 cases of breast cancer-specific mortality, and 21,945 cases of all-cause mortality were observed. With regard to breast cancer recurrence, 7 studies assessed pre-diagnosis alcohol consumption (relative risk (RR) 1.02, 95% confidence interval (95% CI) 0.77-1.37, p = 0.88) and 3 studies assessed post-diagnosis alcohol consumption (RR 0.96, 95% CI 0.85-1.10, p = 0.57), and no significant increase or decrease in risk was observed. With regard to breast cancer-related mortality, 19 studies assessed pre-diagnosis alcohol consumption (RR 1.02, 95% CI 0.93-1.11, p = 0.69), 9 studies assessed post-diagnosis alcohol consumption (RR 0.96, 95% CI 0.77-1.19, p = 0.70), and no significant increase or decrease in risk was observed. With regard to all-cause mortality, 18 studies assessed pre-diagnosis alcohol consumption (RR 0.90, 95% CI 0.82-0.99, p = 0.02), 8 studies assessed post-diagnosis alcohol consumption (RR 0.88, 95% CI 0.74-1.02, p = 0.08), and pre-diagnosis alcohol consumption was associated with a significantly decreased risk. With regard to cardiovascular disease mortality and alcohol consumption, 2 studies assessed it, and the RRwas 0.47 (95% CI 0.28-0.79, p = 0.005), showing that alcohol consumption was associated with a significantly decreased risk. The limitations of this study are that drinking status was mainly based on a questionnaire survey, which is somewhat inaccurate and has many confounding factors, and the cut-off value for the maximum alcohol intake in many studies was low, and it is possible that the actual intake was only an appropriate amount. In many countries, a standard drinking amount is set, and wise decisions are required., (© 2023. The Author(s).)

Background: Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited., Methods: The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented., Results: In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, p trend  = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, p trend  = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, p trend  = 0.004)., Conclusion: The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.

Background: Computer-aided detection (CAD) increases breast cancer detection, but its cost-effectiveness is unknown for breast cancer screening in Japan. We aimed to determine whether screening mammography diagnosed by one physician using CAD is cost-effective when compared with the standard double reading by two physicians., Methods: We established our model with a decision tree and Markov model concept based on feasible screening and clinical pathways, combined with prognosis of the health state transition of breast cancer. Cost-effectiveness analysis between double reading by two readers and single reading with CAD by one reader was performed from a social perspective in terms of the expected cost, life expectancy and incremental cost-effectiveness ratio (ICER). The hypothetical population comprised 50-year-old female breast cancer screening examinees. Only direct medical costs related to breast cancer screening and treatment were considered. One simulation cycle was 2 years, and the annual discount rate was 3 %. Sensitivity analysis was performed to evaluate the robustness of the model and input data., Results: Single reading with CAD increased expected costs by 2,704 yen and extended life expectancy by 0.0087 years compared with double reading. The ICER was 310,805 yen per life year gained, which is below the threshold. Sensitivity analysis showed that the sensitivity and specificity of CAD and the number of breast cancer screening examinees greatly affected the results., Conclusions: Single reading using CAD in mammography screening is more cost-effective than double reading, although the results are highly sensitive to the sensitivity and specificity of CAD and the numbers of examinees.

Background: The effectiveness of screening mammography (MMG) has mainly been demonstrated by studies in western countries. This study was conducted to evaluate cumulative survival and the risk of breast cancer death among Japanese women aged 40-69 years with screening-detected and interval breast cancer divided into three groups: MMG with clinical breast examination (CBE), CBE alone, and self-detection., Methods: By matching a list of 126,537 women (358,242 person-screenings) who participated in the Miyagi Cancer Society Screening program between 1 April 1995 and 31 December 2002 with the Miyagi Prefectural Cancer Registry, 429 MMG with CBE, 522 CBE, and 3,047 self-detected cases were included in this study. Follow-up was performed until the date of death or 31 December 2007. Survival was estimated by the Kaplan-Meier method. The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for breast cancer death., Results: Five-year survival for women in the MMG with CBE, CBE, and self-detection groups was 96.8, 92.7, and 86.6 %, respectively. The HR (95 % CI) for breast cancer death was 2.38 (0.72-7.94) among CBE-screened and 4.44 (1.42-13.89) among self-detected cases for women aged 40-49 years, but was 3.00 (1.63-5.50) among CBE-screened and 4.51 (2.69-7.56) among self-detected cases for women aged 50-69 years relative to cases screened by use of MMG with CBE., Conclusions: In terms of the survival and risk of breast cancer death, MMG with CBE may be more effective than MMG alone or self-detection for Japanese women aged 40-69 years.

Background: The US Preventative Services Task Force assesses the efficacy of breast cancer screening by the sum of its benefits and harms, and recommends against routine screening mammography because of its relatively great harms for women aged 40-49 years. Assessment of the efficacy of screening mammography should take into consideration not only its benefits but also its harms, but data regarding those harms are lacking for Japanese women., Methods: In 2008 we collected screening mammography data from 144,848 participants from five Japanese prefectures by age bracket to assess the harms [false-positive results, performance of unnecessary additional imaging, fine-needle aspiration cytology (FNA), and biopsy and its procedures]., Results: The rate of cancer detected in women aged 40-49 years was 0.28%. The false-positive rate (9.6%) and rates of additional imaging by mammography (5.8%) and ultrasound (7.3%) were higher in women aged 40-49 years than in the other age brackets. The rates of FNA (1.6%) and biopsy (0.7%) were also highest in women aged 40-49 years. However, they seemed to be lower than the rates reported by the Breast Cancer Surveillance Consortium (BCSC) and other studies in the US., Conclusions: The results, although preliminary, indicate the possibility that the harms of screening mammography for Japanese women are less than those for American women.