Japanese women have lower recurrence of breast cancer

May 1 2005

Early-stage breast cancer patients of Japanese descent that are treated with a lumpectomy and radiation therapy are more likely to be cured of their cancer than women of other ancestries, according to a new study published in the May 2005 issue of the International Journal of Radiation Oncology-Biology-Physics, the official journal of ASTRO, the American Society for Therapeutic Radiology and Oncology.

The study, conducted on 896 patients treated at Kuakini Medical Center in Honolulu from 1990 to 2001, found that only six women (.67 percent) experienced a local recurrence of their breast cancer in the first six years after treatment. The patients in the study all had Tis, T1 or T2 tumors, considered early stage, with no spread to other organs or distant sites in the body. Seventy-four percent of the patients in this study were of Japanese heritage.

This figure is remarkable considering the local recurrence rates for women of all ethnicities with breast cancer published from academic centers all over the world range from two to 16 percent. Overall, the Kuakini Medical Center's survival data were superior to the National Cancer Data Base.

"This low rate of local relapse is extraordinary and unmatched by the published data results generally cited in the literature," said Mark Kanemori, M.D., lead author of the study and a radiation oncologist at Kuakini Medical Center. "This study suggests that there are biological factors that may be related to ethnicity. Hopefully, this will spark interest in the academic community to further research in this area. Identifying predictive factors of cancer biology may lead to improvements in our ability to properly select appropriate cancer treatments for our patients."