• Ulrik Wallin, David Rothenberger, Ann Lowry, Russell Luepker, and Anders Mellgren.
• Division of Colon and Rectal Surgery, Department of Surgery, University of Minnesota, Minneapolis, Minnesota 52242, USA. ulrik-wallin@uiowa.edu
• Dis. Colon Rectum. 2013 Jul 1;56(7):859-68.

BackgroundPreoperative chemoradiation therapy in patients with rectal cancer results in pathologic complete response in approximately 10% to 30% of patients. Accurate predictive factors for obtaining pathologic complete response would likely influence the selection of patients best treated by chemoradiation therapy as the primary treatment without radical surgery.ObjectiveThe aim of this study was to evaluate the impact of tumor size, stage, location, circumferential extent, patient characteristics, and pretreatment CEA levels on the development of pathologic complete response after chemoradiation therapy.DesignThis study is a retrospective review.Settings And PatientsFive hundred thirty patients treated with preoperative chemoradiation therapy and radical surgery for rectal adenocarcinoma between 1998 and 2011 were identified. A total of 469 patients remained after excluding patients with a history of pelvic radiation (n = 2), previous transanal endoscopic microsurgery or polypectomy of the primary lesion (n = 15), concurrent malignant tumor (n = 14), and no information about pre- or posttreatment T stage in the chart (n = 30). Preoperative CEA levels were available for 267 patients (57%).InterventionsPreoperative chemoradiation therapy and total mesorectal excision were performed in patients with rectal cancer.Main OutcomeThe primary outcome measured was pathologic complete response.Results: Ninety-six patients (20%) were found to have a pathologic complete response in the operative specimen. Low pretreatment CEA (3.4 vs 9.6 ng/mL; p = 0.008) and smaller mean tumor size (4.2 vs 4.7 cm; p = 0.02) were significantly associated with pathologic complete response. Low CEA levels and interruption in chemoradiation therapy were significant predictors of pathologic complete response in the multivariate analysis. When stratifying for smoking status, low CEA level was significantly associated with pathologic complete response only in the group of nonsmokers (p = 0.02).LimitationsThis study was limited by its retrospective design, missing CEA values, and lack of tumor regression grade assessment.ConclusionsWe demonstrated an association between low pretreatment CEA levels, interruption in chemoradiation therapy, and pathologic complete response in patients treated with neoadjuvant chemoradiation therapy for locally advanced rectal cancer. The predictive value of CEA in smokers can be limited, and further studies are needed to evaluate the impact of smoking on the predictive value of CEA levels for pathologic complete response in rectal cancer.

38 keywords...

hide…