Remarkable advances in treatments for cancer over the past 2 decades are enabling increased personalized care for patients with the disease. However, the growing complexity of treatment methods, including targeted therapy, immunotherapy, and advanced oral therapy, make it challenging for medical oncologists to stay current on treatment options across a wide variety of cancer types. The result is that subspecialization in medical oncology, in which oncologists focus on a narrow set of cancer types, is growing.
A retrospective cohort study examining trends in oncologist subspecialization and the differences in utilization of subspecialized cancer care in the United States has found that while subspecialization in oncology is increasing, it is unevenly distributed, with growing differences in utilization between high- and low-income areas and regions in the United States, despite higher cancer mortality rates in low-income areas. These differences in utilization could reflect systematic barriers to care. The study by Karadakic et al was published in Annals of Internal Medicine.
Study Methodology
Researchers used data from Medicare Part B and Part D from 2007 to 2021 for their analysis. They examined trends in subspecialization among 18,633 medical oncologists. The study population included fee-for-service Medicare beneficiaries diagnosed with cancer—including breast, gastrointestinal, gynecologic, head and neck, hematologic, prostate/genitourinary, dermatologic, thoracic, among other cancer types—who initiated chemotherapy between 2008 and 2020. Chemotherapy episodes were defined using methods from the Oncology Care Model. Subspecialization was identified based on whether oncologists managed more than 80% of chemotherapy episodes within a single cancer category. Outcomes included the annual share of oncologists classified as subspecialists, and the share of chemotherapy episodes managed by these oncologists, stratified by cancer type, geography, and socioeconomic characteristics.
Results
The researchers found that among the 18,633 oncologists and 9.25 million chemotherapy episodes recorded, the proportion of episodes managed by subspecialists increased from 9% in 2008 to 18% in 2020. Utilization varied widely across cancer types and regions, with the highest levels observed in large metropolitan areas. Differences by income widened over time—for example, in 2020, 27.6% of episodes in the highest-income counties were managed by subspecialists, compared with only 8.8% in the lowest-income counties, despite higher cancer mortality rates in the latter.
“Subspecialization in oncology is increasing, but is unevenly distributed, with growing differences in utilization across income groups and regions. …Strategies to improve resource allocation, support the accessibility of subspecialties in underserved areas, and enhance care coordination between general oncologists and subspecialists could help bridge the existing gaps,” concluded the study authors.
Michael L. Barnett, MD, MS, Professor of Health Services, Policy & Practice, Brown School of Public Health, is the corresponding author of this study.
Disclosure: Funding for this study was provided by the National Institute on Aging. The study authors’ conflict of interest disclosures can be found at www.acpjournals.org.
