Intensity-modulated radiotherapy (IMRT) is significantly associated with lower all-cause, cardiac, and other-cause mortality rates in patients with esophageal cancer (EC), according to a study published online ahead of print in the journal Cancer.1
The researchers sought to clarify the clinical impact of IMRT, which has superior normal organ-sparing effect compared with 3-dimensional radiotherapy (3D), on survival and cardiopulmonary mortality in patients with EC.
For this study, 2553 patients older than 65 years with nonmetastatic EC diagnosed between 2002 and 2009 were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare and Texas Cancer Registry-Medicare databases. The patients were treated with either 3D (n=2240 patients) or IMRT (n=313 patients) within 6 months of diagnosis.
The 2 cohorts were well balanced with regard to various patient, tumor, and treatment characteristics, including geographic location (urban/metropolitan or rural areas); exceptions were marital status, year of diagnosis, and SEER region. IMRT use increased from 2.6% in 2002 to 30% in 2009, whereas the use of 3D decreased from 97.4% in 2002 to 70% in 2009.
Outcomes in the 2 cohorts were compared using inverse probability of treatment weighting adjustment. IMRT was not found to be associated with EC-specific mortality (HR, 0.93; 95% CI, 0.80-1.10) or pulmonary mortality (HR, 1.11; 95% CI, 0.37-3.36), but was significantly associated with lower all-cause mortality (HR, 0.83; 95% CI, 0.72-0.95), cardiac mortality (HR, 0.18; 95% CI, 0.06-0.54), and other-cause mortality (HR, 0.54; 95% CI, 0.35-0.84) on propensity score inverse probability of treatment weighting-adjusted multivariate analysis.
Similar associations were noted after adjusting for type of chemotherapy, physician experience, and sensitivity analysis removing hybrid radiation claims.
1. Lin SH, Zhang N, Godby J, et al. Radiation modality use and cardiopulmonary mortality risk in elderly patients with esophageal cancer [published online ahead of print December 30, 2015]. Cancer. doi:10.1002/cncr.29857.