The Emerging Non-operative Management of Non-metastatic Rectal Cancer: A Population Analysis

Recent studies have piloted a nonoperative approach in patients with a complete clinical response to neoadjuvant chemoradiation for non-metastatic rectal cancer. This study evaluated these outcomes in the Surveillance, Epidemiology, and End Results (SEER) database.

Using SEER database 8.1.5, we identified patients diagnosed with stage II-III rectal adenocarcinoma between 2004-2011, treated with radiation alone (RT), RT then surgery (RT-S), or surgery then RT (S-RT). Utilization patterns were investigated for all three groups and evaluated using the Chi-squared test. A secondary analysis was limited to current approaches (RT or RT-S). Overall survival (OS) was compared using the log-rank test. Predictors for nonoperative management were compared by multivariable analyses.

From 2004 to 2011, utilization of RT increased from 4% to 8%, RT-S from 57% to 75%, and S-RT decreased from 39% to 18% (p<0.001). In the secondary analysis, predictors for nonoperative management were lower T-stage and N-stage tumors, non-White race, and male sex. With 5,909 evaluable patients at a median follow-up of 35 months, the 5-year OS in the RT group was 56% vs. 80% in the RT-S group (log-rank p<0.001).

Nonoperative management of rectal cancer is increasing despite an apparent detriment in OS compared to a combined modality approach, that may reflect a selection bias in the SEER database.