Utilization of preoperative radiation therapy in the management of rectal cancer: A population-based analysis.

Abstract

Preoperative radiation therapy (RT) improves local control in resectable rectal cancer compared with postoperative RT or surgery alone. Although clinical practice guidelines exist, adherence to recommendations for preoperative RT is unclear. This population-based study examines preoperative RT utilization rates for rectal cancer patients in a Canadian province and investigates factors influencing its usage. Between 2004 and 2009, all stage II and III rectal cancer patients treated with definitive surgery were identified using the Manitoba Cancer Registry. Patients not receiving resection of the primary tumor, as determined by administrative procedure codes, were excluded. Factors potentially influencing preoperative RT utilization, including age, gender, stage, year of diagnosis, and geographic distance from RT facility, were analyzed using logistic regression analyses. Overall survival outcomes were also examined. The registry identified 776 patients meeting the study inclusion criteria. Preoperative RT utilization increased from 3% in 2004 to 41% in 2009. Postoperative RT utilization decreased from 48% to 17% during the same period. Rates of surgery alone remained stable at 40%-50%. Factors influencing preoperative RT utilization were younger age (P < .0001), stage III disease (P = .02), and later year of diagnosis (P < .0001). Elderly patients age 70 years and over were predominantly treated with surgery alone. Actuarial 5-year overall survival for patients receiving preoperative RT postoperative RT, and surgery alone were 80%, 73%, and 58%, respectively. Steadily increasing utilization of preoperative compared with postoperative RT is evident; however, rates of surgery alone remained unchanged. Strategies to improve preoperative RT utilization, particularly among elderly patients, are needed.