Subspecialization in Oncology Increasingly Utilized

MONDAY, Aug. 11, 2025 (HealthDay News) — Subspecialization in oncology is increasing, but varies widely across cancer types and regions, according to a study published online Aug. 12 in the Annals of Internal Medicine.

Rene Karadakic, Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues conducted a retrospective cohort study using Medicare claims data from 2007 to 2021 to quantify trends in oncologist subspecialized cancer care in the United States. Subspecialization was identified if oncologists managed more than 80 percent of chemotherapy episodes within a single cancer category.

The researchers found that from 2008 to 2020, there was an increase in the proportion of episodes managed by subspecialists, from 9 to 18 percent, among 18,633 oncologists and 9.25 million chemotherapy episodes. Across cancer types and regions, there was wide variation in utilization, with the highest levels seen in large metropolitan areas. Over time, differences by income widened: In 2020, 27.6 and 8.8 percent of episodes were managed by subspecialists in the highest-income and the lowest-income counties, respectively, despite higher cancer mortality in the latter.

“If patients of subspecialists receive more guideline-recommended care or have better outcomes, a critical question that requires further investigation, then targeted policies may be needed to address differences in utilization of subspecialized care,” the authors write.

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