Patterns of Care Study for Breast-conserving Therapy: Comparison of Process Survey in Japan and the US

Purpose/Objective: The Patterns of Care Study was originally developed in the United States and has been used to assess the evaluation and treatment patterns of malignancies. The Japan Patterns of Care Study (JPCS) Group started the first national survey in 1998 and has carried out two national surveys to date. Breast-conserving therapy (BCT) for breast cancer was introduced to Japan in the late eighties although it was started in the early seventies in North America and Europe. This study investigate problems associated with the process of care for patients undergoing BCT in Japan compared with those in the United States. Materials/Methods: The JPCS survey on the process of BCT collected data on 746 patients who were treated between 1999 and 2001 from 76 institutions by two-stage cluster sampling. Similarly, the survey of the Patterns of Care Study of the United States (USPCS) collected 353 patients who underwent BCT between 1998 and 1999. The data included patient characteristics, clinical and pathologic factors, regimen of systemic therapy, and surgical and radiotherapy (RT) details. Results: The median age of the JPCS patients was 52 years and that of the USPCS patients was 57 years. In JPCS, 57.1% of patients were initially diagnosed by fine needle aspiration compared with 12.7% in USPCS. However, core needle biopsy and excisional biopsy were performed for 37.1% and 47.3% of USPCS patients, respectively compared with 9.1% and 17.1% in Japan. Quadrantectomy was performed for 57.0% of the patients and partial mastectomy or wide excision for 37.5% in JPCS. USPCS shows that partial mastectomy or wide excision was performed for 48.4% of patients and excisional biopsy for 27.5%.The assessment of estrogen and progesterone receptor was commonly demonstrated with 78.0% and 75.2% in JPCS, although the rate was lower than that of USPCS with 82.2% and 81.0%, respectively. In JPCS, 90.9% of the patients underwent axillary dissection and 12.1% of patients underwent sentinel lymph node biopsy, as compared to 83.0% and 21.0% in USPCS, respectively. The total dose to the breast ranged from 37.8Gy to 60.0Gy (median 50Gy) in JPCS, and from 18.0GY to 60.5Gy (median 50Gy) in USPCS. Only 26.2 % of patients in JPCS received boost, while 85.6% of patients in USPCS received boost. Tamoxifen was administered to 68.8% of JPCS patients and 55.8% of USPCS patients. The use of chemotherapy including oral administration of 5-FU or its derivatives in JPCS was similar to that of USPCS (35.0% and 36.0%, respectively), even though oral administration of 5-FU or its derivatives is very common in Japan. Conclusions: There was a younger distribution in JPCS compared with the patients in USPCS. The process from diagnosis to surgery for primary tumor differed between JPCS and USPCS. The type of breast surgery was extensive and the use of axillary dissection was common in JPCS compared with USPCS. Concerns with radiation therapy, boost irradiation was less common in JPCS than USPCS, although the total breast dose did not differ markedly.

SSK25-05

Patterns of Care Study for Breast-conserving Therapy: Comparison of Process Survey in Japan and the US