Reduced Use of Radiotherapy for Unresectable Pancreatic Adenocarcinoma in the United States
In a study reported in a research letter in JAMA Surgery, Shapiro et al found that use of radiotherapy in unresectable pancreas cancer has decreased over time and that disparities in use can be identified.
Decreasing Use
The study involved Surveillance, Epidemiology, and End Results (SEER) data on 9,786 patients diagnosed with localized unresectable pancreatic adenocarcinoma between 1988 and 2010.
Use of radiotherapy decreased significantly from 52% in 1988 to 1992 to 39% in 2008 to 2010 (odds ratio [OR] = 0.60, P = .001, on multivariate analysis).
Factors Associated With Use
On multivariate analysis, factors significantly associated with use of radiotherapy in addition to years of diagnosis consisted of age ≥ 65 (OR = 0.56, P < .001), married status (OR = 1.43, P < .001), African American vs white race (OR = 0.80, P < .01), non-Hispanic ethnicity (OR = 1.31, P < .01), Northeast (OR = 1.31, P < .001), Midwest (OR = 2.27, P < .001), and Southeast (OR = 1.19, P = .02) vs Pacific West geographic region. Sex, tumor size, and lymph node involvement were not independently associated with use of radiotherapy. Tumor grade data were missing for more than half of patients; it was significantly associated with use of radiotherapy on univariate analysis, but not when included in multivariate analysis
Use of radiotherapy was associated with significantly better overall survival independent of other clinicopathologic factors (median 10 vs 6 months, hazard ratio = 0.69, P < .001).
The investigators concluded: “The use of radiation is likely on the decline owing to the proven efficacy of chemotherapy for locally unresectable pancreatic cancer without convincing data showing an additive effect for radiotherapy. Despite the limitations in our survival analysis, there may be a cohort of patients with localized unresectable pancreatic cancer who could benefit from radiation, and this is worthy of further investigation. If radiotherapy is thought to be of benefit, efforts should be made to minimize disparities in its use.”
Jason S. Gold, MD, of VA Boston Healthcare System and Harvard Medical School, is the corresponding author for the JAMA Surgery article.
The study was supported by the Department of Veterans Affairs Office of Research and Development.
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