The high and heterogeneous burden of breast cancer in Hawaii: A unique multiethnic U.S. Population.

BACKGROUND: While breast cancer incidence and mortality rates differ across racial/ethnic populations in the U.S., little is known about Asian and Pacific Island subpopulations. Hawaii is one of the most racially/ethnically diverse states in the U.S. Overall, Hawaii ranks 5th highest for breast cancer incidence in the nation (2010-2014) and rates have increased in recent years despite a stable national trend. In contrast, for breast cancer mortality, Hawaii has the 3rd lowest rate in the nation, with rates demonstrating a steady decline for nearly 3 decades.
METHODS: We examined incidence and mortality trends from 1984-2013 across the five major racial/ethnic populations of Hawaii (Native Hawaiian, White, Japanese, Chinese, and Filipino) using Hawaii's Surveillance, Epidemiology, and End Results (SEER) registry data.
RESULTS: With the exception of Chinese, all groups experienced increasing incidence over the thirty year period. While Japanese experienced the most pronounced recent increase, with incidence now exceeding that of Whites, their mortality rates have remained low for decades. Native Hawaiians have consistently had the highest incidence and mortality rates in the state. The incidence rates of hormone receptor (HR)-positive breast cancer were higher among Japanese and Native Hawaiians as compared to Whites. Relative to Whites, Native Hawaiians also had a higher incidence rate of the HER2-positive subtype and, Japanese, of the triple-negative (HR-/HER2-) subtype of breast cancer.
CONCLUSIONS: Studies such as this underscore the importance of considering the heterogeneity in breast cancer rates and subtypes across the different racial/ethnic populations.