Trends in adjuvant therapy after breast-conserving surgery for ductal carcinoma in situ of breast: a retrospective cohort study using the National Breast Cancer Registry of Japan

Survival trends and patient characteristics between 2004 and 2016 for breast cancer in Japan based on the National Clinical Database-Breast Cancer Registry

This is a prognostic report by the Japanese Breast Cancer Society on breast cancer extracted from the National Clinical Database-Breast Cancer Registry of Japan. Here, we present a summary of 457,878 breast cancer cases registered between 2004 and 2016. The median follow-up duration was 5.6 years. The median age at the start of treatment was 59 years (5-95%: 38-82 years) and increased from 57 years between 2004 and 2008 to 60 years between 2013 and 2016. The proportion of patients with Stage 0-II disease increased from 74.5% to 78.3%. The number of cases with estrogen and progesterone receptor positivity increased from 74.8% to 77.9% and 60.5% to 68.1%, respectively. Regarding (neo-)adjuvant chemotherapy, the taxane (T) or taxane-cyclophosphamide (C) regimen increased by 2.4% to 8.2%, but the (fluorouracil (F)) adriamycin (A)-C-T/(F) epirubicin (E)C-T and (F)AC/(F)EC regimens decreased by 18.6% to 15.2% and 13.5% to 5.0%, respectively. Regarding (neo-)adjuvant anti-human epidermal growth factor-2 (HER2)-targeted therapy, the use of trastuzumab increased from 4.6% to 10.5%. The rate of sentinel lymph node biopsy increased from 37.1% to 60.7%, while that of axillary dissection decreased from 54.5% to 22.6%. Improvements in disease-free and overall survival were observed in patients with HER2-positive breast cancer, but there was no apparent trend in patients with hormone receptor-positive, HER2-negative, or triple-negative breast cancers.

2020 Annual Report of National Clinical Database-Breast Cancer Registry: 10-year mortality of elderly breast cancer patients in Japan

The Japanese Breast Cancer Society initiated the breast cancer registry in 1975, which transitioned to the National Clinical Database-Breast Cancer Registry in 2012. This annual report presents data from 2020 and analyzes the ten-year mortality rates for those aged 65 and older. We analyzed data from 93,784 breast cancer (BC) cases registered in 2020 and assessed 10-year mortality rates for 36,279 elderly patients diagnosed between 2008 and 2012. In 2020, 99.4% of BC cases were females with a median age of 61. Most (65%) were diagnosed at early stages (Stage 0 or I). Breast-conserving surgery rates varied with stages: 58.5% at cStage I, 30.8% at cStage II, and 13.1% at cStage III. Sentinel lymph node biopsy was done in 73.6% of cases, followed by radiotherapy in 70% of those post-conserving surgery and chemotherapy in 21.1% post-surgery. Pathology showed that 63.4% had tumors under 2.0 cm, 11.7% had pTis tumors, and 77.3% had no axillary lymph node metastasis. ER positivity was seen in 75.1%, HER2 in 14.3%, and 30% had a Ki67 positivity rate above 30%. Across all stages and subtypes, there was a trend where the 10-year mortality rates increased for individuals older than 65 years. In Stage I, many deaths were not directly linked to BC and, for those with HER2-type and triple-negative BC, breast cancer-related deaths increased with age. Within Stage II, patients older than 70 years with luminal-type BC often experienced deaths not directly linked to BC, whereas patients below 80 years with HER2-type and triple-negative BC, likely had breast cancer-related deaths. In Stage III, breast cancer-related deaths were more common, particularly in HER2 and triple-negative BC. Our prognostic analysis underscores distinct mortality patterns by stage, subtype, and age in elderly BC patients. It highlights the importance of personalized treatment strategies, considering subtype-specific aggressiveness, age-related factors, and comorbidities.

Annual report of the Japanese Breast Cancer Registry for 2019

This is an annual report by the Japanese Breast Cancer Society regarding the clinical data on breast cancer extracted from the National Clinical Database-Breast Cancer Registry (NCD-BCR) of Japan. Here, we present an updated summary of 98,300 breast cancer cases registered in 2019. The median age at cancer diagnosis was 61 years (interquartile range 49-72 years), and 30.6% of the breast cancer patients were premenopausal. Of the 93,840 patients without distant metastases, 14,118 (15.0%) and 42,047 (44.8%) were diagnosed with stage 0 and I disease, respectively. Breast-conserving surgery was performed in 42,080 (44.8%) patients. Regarding axillary procedures, 62,677 (66.8%) and 7371 (7.9%) patients underwent sentinel node biopsy and axillary node dissection after biopsy, respectively. Whole breast irradiation was administered to 29,795 (70.8%) of the 42,080 patients undergoing breast-conserving surgery. Chest wall irradiation was administered to 5524 (11.1%) of the 49,637 patients who underwent mastectomy. Of the 6912 clinically lymph node-negative patients who received preoperative therapy, 5250 (76.0%) and 427 (6.2%) underwent sentinel node biopsy and axillary node dissection after biopsy, respectively; however, 602 (8.7%) patients initially underwent axillary node dissection without biopsy.

Risk factors for arm lymphedema following breast cancer surgery: a Japanese nationwide database study of 84,022 patients

BACKGROUND

Although arm lymphedema is a well-known complication following breast cancer surgery, previous studies involving a small population showed inconsistent results regarding the risk. Therefore, we examined the risk factors using a Japanese nationwide database.

METHODS

Female patients who underwent breast cancer surgery from April, 2016, to March, 2020, were identified from a Japanese nationwide database. Multivariable survival analyses for 19 baseline factors (12 patient characteristics, four tumor characteristics, and three surgical procedures) were conducted to investigate risk factors associated with treatments for postoperative lymphedema (such as lymphatic bypass, compositive drainage therapy, hospitalization, and Kampo use) with a multilevel model to adjust for within-hospital clustering. We also conducted multivariable analysis for five postoperative factors (two local complications and three postoperative therapies) with adjustment for 19 baseline factors.

RESULTS

The study included 84,022 patients; 1547 (1.8%) received treatments for lymphedema during a median follow-up of 119 weeks (interquartile range, 59-187 weeks). Young age, obesity, smoking, collagen diseases, advanced cancer stage, total mastectomy, axillary dissection, postoperative bleeding, chemotherapy, and radiotherapy were identified as risk factors. Postoperative chemotherapy (hazard ratio, 3.78 [95% confidence interval, 3.35-4.26]) and axillary dissection (2.46 [1.95-3.11]) showed the highest odds ratio among the risk factors. The cumulative probabilities in high-risk patients reached approximately 3% at 1 year and 6% at 4 years after surgery.

CONCLUSIONS

This study identified several risk factors for postoperative lymphedema in breast cancer surgery. The treatment initiation increased markedly within the first year and gradually after 1 year post-surgery.