691 Background: Neoadjuvant chemoradiation therapy (NACRT) is widely accepted as the standard of care for treatment of locally advanced rectal cancer in the United States. We sought to examine patterns of treatment for locally advanced rectal cancer in US over the past decade. Methods: Using the National Cancer Data Base (NCDB), we identified 66,197 patients diagnosed with stage II-III rectal adenocarcinoma and treated between 2004 and 2012. We described trends in receipt of treatment based on aggregated data for three time periods (2004-2006, 2007-2009, 2010-2012), using trend test. We analyzed 5-yr overall survival (OS) probabilities for 28,550 patients treated between 2004 and 2007. Results: Receipt of NACRT increased significantly over the past decade from 42.9% in 2004-2006 to 50.0% in 2007-2009, and then to 55.0% in 2010-2012 (p < 0.0001). In contrast, use of adjuvant chemoradiation (CRT) decreased steadily from 16.7% in 2004-2006 to 10.5% in 2007-2009, and then to 6.7% in 2010-2012 (p < 0.0001). Similarly, treatment with surgery alone decreased from 13.1% in 2004-2006 to 8.7% in 2010-2012 (p < 0.0001). Older age, presence of comorbidities, larger primary tumor size, lymph node involvement, non-Hispanic white ethnicity, lack of private insurance, and being treated at a non-high case volume facility were associated with a significantly lower chance of receiving NACRT in multivariable logistic regression analysis. 5-yr OS probabilities for patients treated with NACRT, surgery and adjuvant CRT, surgery alone, and definitive CRT were 72.4%, 70.9%, 44.9% and 48.8%, respectively. Conclusions: Utilization of NACRT prior to surgery in US patients diagnosed with locally advanced rectal cancer has substantially increased over the past decade. However, only about half of these patients currently receive the standard therapy as recommended by national guidelines, and there may be social and economic barriers to receiving the standard of care. Tri-modality therapy is associated with the best outcomes for these patients, and surgery alone or definitive chemo-radiation should only be reserved for patients unable to tolerate tri-modality therapy.
Adjuvant Radiation for Rectal Cancer: Do We Measure Up to the Standard of Care? An Epidemiologic Analysis of Trends Over 25 Years in the United States