Study reveals disparities in subspecialized cancer care and its impact on patient outcomes

Subspecialization within oncology is on the rise, but its adoption varies significantly across cancer types and regions, according to a new study published in the Annals of Internal Medicine. The research highlights how differences in access to subspecialized cancer care could affect patient outcomes, especially in areas with lower income.

Led by Dr. Rene Karadakic of the Harvard T.H. Chan School of Public Health, the study analyzed Medicare claims data from 2007 to 2021, examining trends in how oncologists provide care for cancer patients. The researchers defined "subspecialization" as oncologists who managed more than 80% of chemotherapy episodes within a single cancer type.

From 2008 to 2020, the proportion of chemotherapy episodes managed by subspecialists more than doubled, from 9% to 18%. This growth reflects the increasing trend of oncologists specializing in particular cancer types. However, the study also found that subspecialization is not evenly distributed across the United States.

The highest levels were seen in large metropolitan areas, while rural and lower-income regions had notably fewer subspecialized providers. In fact, the gap by income has grown over time.

By 2020, 27.6% of chemotherapy episodes in the highest-income counties were managed by subspecialists, compared to just 8.8% in the lowest-income counties, despite the fact that cancer mortality is often higher in these underserved areas.

“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.

The findings underscore a growing challenge in cancer care: as subspecialization increases, so does the disparity in access to it, particularly among vulnerable populations. The study suggests that further research is needed to explore whether subspecialized care leads to improved outcomes for patients, and if so, how policies can be implemented to reduce disparities in care across different income groups and regions.