Sphincter preservation rates after radical resection for rectal cancer in the United States veteran population: opportunity for improvement in early disease.

BACKGROUND: Sphincter preservation (SP) is an important goal of rectal cancer surgery. We hypothesized that SP rates among veteran patients have increased and are comparable to national rates, and that a subset of patients with early disease still undergo non-SP procedures.
METHODS: Patients with nonmetastatic primary rectal adenocarcinoma who underwent curative-intent rectal resection were identified from the Veterans Affairs Central Cancer Registry (VACCR) database (1995-2010). SP trends over time were described and compared to the Surveillance, Epidemiology, and End-Results (SEER) population. Subset analysis was performed in patients with nonirradiated, pathologic stage 0-I rectal cancers, a population that may qualify for novel SP strategies.
RESULTS: Of 5,145 study patients, 3,509 (68 %) underwent SP surgery. The VACCR SP rate increased from 59.9 % in 1995-1999 to 79.3 % in 2005-2010, when it exceeded that of SEER (76.9 %, p = 0.023). On multivariate analysis, recent time period was independently associated with higher likelihood of SP (odds ratio [OR] 2.64, p < 0.001). Preoperative radiotherapy (OR 0.51, p < 0.001) and higher pathologic stage (OR 0.37, stage III, p < 0.001) were negative predictors. In patients with nonirradiated pathologic stage 0-I cancers, SP rates also increased, but 25 % of these patients underwent non-SP procedures. Within this subset, patients with clinical stage 0 and I disease still had significant rates of abdominoperineal resection (7.7 and 17.0 %, respectively).
CONCLUSIONS: SP rates among veterans have increased and surpass national rates. However, an unacceptable proportion of patients with stage 0-I rectal cancers still undergo non-SP procedures. Multimodal treatment with local excision may further improve SP rates in this subset of patients.