Breast Cancer Surgery Practice Patterns in Hawai'i Compared to the Rest of the U.S

Women with early stage breast cancer have two therapeutic surgical options for local control: breast conserving surgery (BCS) or mastectomy. This study aimed to compare practice patterns for breast cancer surgery in Hawai'i (HI) and the rest of the United States (US). Retrospective data from the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) program were evaluated for women diagnosed with early stage primary breast cancer between 2004 and 2018. First course surgical treatment was compared between Hawai'i and the rest of the US and evaluated by stage, race/ethnicity, and age. A total of 1 160 914 female breast cancer patients with in situ, stage 1 or 2 disease were evaluated (HI 20 434 vs US SEER 1 140 480). The proportion of patients treated with BCS was higher among Hawai'i patients compared to the rest of the US (HI 56.3% vs. US 53.4%, P≤.001), regardless of stage. Hawai'i had significantly higher percentages of BCS compared to the rest of the US among Asian (HI 58.0% vs. US 49.7%, P<.001) and Native Hawaiian/Other Pacific Islander (HI 54.0% vs. US 51.3%, P=.008) women. The percentage of BCS was also significantly higher among both younger and older women in Hawai'i compared to those in the rest of the US (HI 49.8% vs. US 44.1%, P<.001; HI 8.0% vs. US 55.9%, P<.001). Between 2004 to 2018, there was a gradual reduction in BCS in younger women across the nation. Using a nationwide dataset, higher BCS percentages were seen in Hawai'i compared to the rest of the US with differences seen according to stage, race/ethnicity, and age.