Skip to content

Shepherd Research Lab

    Breast Cancer Risk Assessment in Hawaiʻi and the USAPI

    About The Study

    This study is funded by the U54 Grant #5U54CA143727: University of Guam/University of Hawaii Cancer Center Partnership under Dr. Neal Palafox. Since 2003, the University of Hawaiʻi Cancer Center (UH Cancer Center) and the University of Guam (UOG) have worked in partnership to explore the reasons behind significant cancer health disparities among Pacific Islanders in Hawaiʻi, Guam and the neighboring U.S. Associated Pacific Islands (USAPI). The University of Guam/University of Hawaiʻi Cancer Center Partnership is one of only 14 Partnerships to Advance Cancer Health Equity (PACHE), a program of the NCI that supports cancer research capacity building at minority-serving institutions and collaborative research addressing cancer health disparities and their impact on underserved and socio-economically disadvantaged populations. The UOG/UH Cancer Center Partnership is the only PACHE serving Pacific Islanders (PI), with an emphasis on Micronesians. The partnership addresses cancer health disparities through research, training, and community outreach.


    Despite recent advances in early detection and treatment, breast cancer remains the second leading cause of cancer-related deaths among women in Hawaii and the USAPI. Efforts to curb this advanced cancer rate have yet to show success even after the implementation of the Breast and Cervical Cancer Early Detection Program (BCCEDP) partially due to either lack of access to mammography screening or low screening participation rates. It would be naive to think that rectifying one problem associated with high advanced-stage rates would bring Hawaii and the USAPI to the rates found in the continental US. However, identifying the women at the highest risk may allow for focusing limited resources on their prevention and early cancer detection.

    Although cumulative incidence rates are well studied in Pacific populations, breast health questions needed to populate existing models are not standardized throughout Hawaii and the USAPI, and the risk models that are available are not well calibrated in the unique race/ethnicities of the Pacific. Risk models either don’t include race/ethnicity (Tyrer-Cuzick version 8, TCv8), are poorly calibrated since they either don’t include breast density (NCI Breast Cancer Risk Assessment Tool, BCRAT), or don’t disaggregate ethnicity into Native Hawaiian/Pacific Islander (NHPI) and Asian subgroups. Previous efforts, such as the Breast Cancer Risk Model Project (BRISK) provide insight to risk factors in Guam and Saipan but were limited in scope with 104 cases and 185 controls. Recent unpublished data from the Breast Cancer Surveillance Consortium (BCSC) investigators showed that 11% or less of the Filipina, Chinese and Japanese women diagnosed with invasive cancer were defined by the BCSC version 2 (BCSCv2) model (12) to be high-risk compared to 46% of the White women with invasive cancer. Thus, even with the previous efforts, the accurate risk of invasive cancer and advanced cancer in individual women of Hawaii and the USAPI cannot be calculated.

    Goals & Aims

    Our long-term goal is to develop accurate and validated breast cancer risk biomarkers that can contribute to reducing advanced breast cancer rates, with an expected decrease in breast cancer mortality, by better identification of women that would benefit from either mammographic or ultrasound breast screening, and risk reduction strategies including diet, exercise, and medication. The Hawaii Pacific Islands Mammography Registry (HIPIMR) is currently active only in Oahu, Hawaii. The HIPIMR is a resource to identify and validate novel image and clinical biomarkers for the diverse ethnic groups of the Pacific region including Native Hawaiians, Chamorro, Japanese, Filipino, Chinese, and other ethnic groups. This proposal is to extend the HIPIMR to Guam as well as the rest of the USAPI. This unique resource will allow us to follow these women for years through multiple screening exams, identify those at high risk of breast cancer, and develop risk-reducing strategies. Our central hypothesis is that the prevalence and importance of breast cancer risk factors and image factors are different in the diverse populations found in Hawaii and the USAPI compared to non-Hispanic White, non-Hispanic Black, and Hispanic women. Our specific aims are the following:

    Aim 1: Explore the mechanisms and structure needed to curate unique clinical risk factors (age, BMI, family history, biopsy status, parity, first live birth age, HT use, menarche/menopause age) and clinical breast density in women undergoing breast cancer screening in Hawaii and Guam. Sub-hypothesis: The distribution of risk factors varies by region, race, and ethnicity in women with and without breast cancer.

    Aim 2: Identify the unique breast density and imaging characteristics of women undergoing screening mammography in Hawaii and Guam. Sub-hypothesis: Breast density is uniquely associated with clinical risk factors, region, and race/ethnicity for women in Hawaii and the USAPI compared to non-Hispanic White women.

    Aim 3. Identify the trends in the prevalence of high breast cancer risk in AANHPI groups of women with and without breast cancer using established models compared to white women. Sub-hypothesis: The accuracy of current risk models are poor in AANHPI groups compared to white women.

    Exploratory: Identify the opportunities and challenges of extending the HIPIMR to the USAPI.


    John Shepherd, PhD


    UH Cancer Center

    JaeYong Choi

    ESI Co-Investigator

    University of Guam

    Brenda Hernandez


    Hawaiʻi Tumor Registry

    Grazyna Badowski


    University of Guam

    Lee Buenconsejo-Lum




    National Cancer Institute
    Through the UH Cancer Center/University of Guam U54 competitive renewal grant