Quantified pathologic response assessed as residual tumor burden is a predictor of recurrence-free survival in patients with rectal cancer who undergo resection after neoadjuvant chemoradiotherapy

BACKGROUND The current study was conducted to determine whether quantified pathologic response assessed as a percentage of residual tumor cells is predictive of recurrence-free survival (RFS) in patients with rectal cancer. METHODS The authors studied 251 patients with rectal adenocarcinoma who were treated with neoadjuvant chemoradiation and radical resection. Quantified pathologic response was defined as an estimated percentage of residual cancer cells in relation to the tumor bed: complete, no residual cancer cells; near-complete, ≤ 5% residual cancer cells; major, > 5%, and