At least $230 million was spent on cancer care delivered outside Hawaiʻi between 2021 and 2023, according to a new study led by researchers at the University of Hawaiʻi Cancer Center . Geographic isolation requires many Hawaiʻi patients to seek advanced cancer therapeutics and clinical trials on the mainland.
Researchers analyzed de-identified commercial insurance claims from the Hawaiʻi Medical Service Association (HMSA) for residents receiving cancer treatment. The data showed that patients with complex cancers, such as leukemia and brain tumors, were most likely to require out-of-state care, highlighting a need to expand local subspecialty capacity.
"Patients who must leave the islands for specialized cancer care bear enormous burdens: On top of medical bills, they may face travel expenses, time away from work, and the emotional challenge of receiving treatment far from home and the support of their loved ones. For some patients, the enormous cost of out-of-state treatment puts that care out of reach," said Hideko Yamauchi, director of clinical affairs at the UH Cancer Center, and the principal investigator for the study.
Analyzing data on why patients seek treatment out-of-state helps the center identify gaps in local services, allowing them to expand specialized care and keep patients closer to their support networks.
'Financial toxicity' places strain on patients
The study found that out-of-state cancer care expenditures totaled approximately $58 million in 2021, rose to $94 million in 2022, and reached nearly $79 million in 2023. Total spending exceeded $230 million during the three-year period.
Patients who must leave the islands for specialized cancer care bear enormous burdens.
—Hideko Yamauchi
Breast cancer accounted for the largest total amount spent on out-of-state care at $59.5 million, due to its high prevalence, researchers said. It was followed by leukemia ($46.4 million), lymphoma ($21.5 million), prostate cancer ($14.9 million), and pulmonary cancer ($14 million).
However, leukemia exhibited the highest proportion of out-of-state spending for treatment, at 39%, followed by lymphoma (29%), central nervous system tumors (27%), multiple myeloma (21%) and breast cancer (21%).
The study analyzed direct medical costs paid via HMSA, excluding out-of-pocket expenses like travel, lodging, and lost income—factors that exacerbate "financial toxicity" for patients.
"A concern raised by these findings is that the patients we can see in the data are only the ones who successfully traveled," Yamauchi said. "The patients we worry about are the ones we cannot see in this data—those who did not travel and faced barriers to accessing specialized care. Understanding that hidden burden is an important next step for research and policy."
Expansion of Hawaiʻi cancer care
Increased investment in high-demand specialty services, advanced diagnostics, and tele-oncology could reduce the need for travel.
"The UH Cancer Center deeply appreciates HMSA, a member of our Hawaiʻi Cancer Consortium , for collaborating on this crucial research. This study demonstrates why continuing to expand cancer care in Hawaiʻi is so important," said Naoto T. Ueno, director of the UH Cancer Center and study co-author.
Initiatives such as the Ho'ōla Early Phase Clinical Research Center (opening July 6) and the Ka ʻUmeke Lama program are now expanding local access to Phase I trials.
Co-authors also included Deborah Taira, professor, Daniel K. Inouye College of Pharmacy, UH Hilo; Mark M. Mugiishi, chief executive officer, HMSA; and Jeffrey Tom, clinical systems director for corporate strategy, HMSA.
