Radiotherapy Rates in the USA Decline for Pancreatic Adenocarcinoma

Pancreatic cancer patients in the USA are significantly less likely to receive radiation therapy now than they were 20 years ago

medwireNews: Research published in JAMA Surgery suggests that administration of radiotherapy for the treatment of locally unresectable pancreatic adenocarcinoma has decreased markedly in the USA over the past two decades.

“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”, speculate Jason Gold, from VA Boston Healthcare System in West Roxbury, Massachusetts, USA, and co-investigators.

Their analysis of Surveillance, Epidemiology, and End Results data of individuals with localised unresectable pancreatic cancer showed that external beam radiotherapy was used in 52% and 39% of patients from 1988 to 1992 and 2008 to 2010, respectively, a difference that was statistically significant.

Multivariate analysis showed significant geographical variation in the administration of radiotherapy, with the most frequent use noted in the Midwest, followed by the Northeast, Southeast and Pacific West regions of the country.

Patients who were 65 years of age and older were also significantly less likely to receive radiation compared with those younger than 65 years (odds ratio [OR]=0.56), as were African–American versus White patients (OR=0.80). Additionally the use of radiotherapy was significantly higher in married than in single individuals (OR=1.43) and in non-Hispanic compared with Hispanic patients (OR=1.31).

By contrast, gender and tumour characteristics, such as size, grade and lymph node involvement, were not associated with radiation use.

The researchers found a significant survival benefit of radiotherapy, with longer overall survival in the 4137 patients who received radiation than in the 5649 individuals who did not, at a median of 10 versus 6 months. But they caution that “selection bias cannot be excluded because data on patients’ comorbidities and use of chemotherapy were not available.”

They conclude: “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.”

Reference

Shapiro M, Rashid NU, Huang Q, et al. Radiation Therapy for Unresectable Pancreatic Adenocarcinoma: Population-Based Trends in Utilization and Survival Rates in the United States. JAMA Surg 2015; Online First 28 January. doi:10.1001/jamasurg.2014.1837

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