Clinicopathological characteristics, practical treatments, prognosis, and clinical issues of older breast cancer patients in Japan.

Background: Minimal data are available to support the clinical management of older breast cancer patients. Consequently, the standard of care remains unclear. Our aim was to clarify the clinicopathological characteristics, practical treatments, and prognosis of older Japanese breast cancer patients and discuss clinical issues.
Methods: We reviewed 132,240 cases, diagnosed between 2004 and 2011, from the Japanese Breast Cancer Registry. Focusing on older patients, we compared data among three age groups: 75 years and over (n = 27,385), 65-74 years (n = 43,839), and 55-64 years (n = 61,016).
Results: Data revealed the proportions of mucinous and apocrine carcinoma were higher in older patients, and they more frequently had clinical stage II and III cancer. Their ER-positive rates were higher, in contrast to the lower HER2-positive, breast-conserving surgery (BCS), post-BCS irradiation, and adjuvant chemotherapy rates. Almost half of the older patients who underwent chemotherapy received CMF or oral 5FU, during hormone therapy, Tamoxifen was administered more frequently. The overall survival rate decreased with age, but the breast cancer-specific survival (BCSS) at 5 years remained similar. The rate of other cause of death in the oldest group was about a half, and more than double that in those aged 55-64 years.
Conclusions: We showed clinical data of older breast cancer patients in Japan. Their disease was more advanced at the time of diagnosis, post-BCS irradiation and primary systemic chemotherapy were omitted more frequently, and overall, BCSS was similar among age categories, although the rate of other causes of death was higher.