title: Accuracy of CT prediction of poor prognostic features in colonic cancer.
abstract: Whilst imaging of poor prognostic features in rectal cancers has assisted pre-operative treatment stratification, such features have yet to be evaluated in colonic cancers. This study aims to develop criteria for identifying poor prognostic features in colonic tumours and assess the accuracy of CT prediction against histopathology. Criteria were developed for predicting T-stage and N-stage, the presence of extramural vascular invasion and involvement of the retroperitoneal surgical margin (RSM). These criteria were tested on 33 patients with colonic cancer who underwent pre-operative high-resolution CT of their tumour. Two radiologists (Obs 1 and Obs 2) identified independently these poor prognostic features and the results were compared with the final histopathological results. Histological agreement and interobserver variation were calculated using the kappa test. Accuracy of CT prediction of tumour extension beyond muscularis propria was 82% (Obs 1) and 70% (Obs 2). Correct prediction of RSM involvement was 76% (95% confidence interval (CI): 57.8-88.9%) and 79% (95%CI: 61.1-91%) for Obs1 and Obs 2, respectively, with significant agreement between observers (kappa = 0.455, p = 0.050). Prognosis was correctly predicted using CT in 82% (95%CI: 61.5-81.2%) (Obs1) and 85% (95%CI: 68.1-94.9%) (Obs2) with moderate agreement (kappa = 0.459, kappa = 0.527, respectively) with histology. In conclusion, CT has potential as the imaging modality of choice in the pre-operative prediction of poor prognostic features in colonic cancers and could play a role in future treatment stratification.
authors.affiliation: Department of Colorectal Surgery, Mayday University Hospital, London Road, Croydon, CR7 7YE.
authors.forename: S
authors.initials: S
authors.lastname: Burton
authors.forename: G
authors.initials: G
authors.lastname: Brown
authors.forename: N
authors.initials: N
authors.lastname: Bees
authors.forename: A
authors.initials: A
authors.lastname: Norman
authors.forename: O
authors.initials: O
authors.lastname: Biedrzycki
authors.forename: A
authors.initials: A
authors.lastname: Arnaout
authors.forename: A M
authors.initials: AM
authors.lastname: Abulafi
authors.forename: R I
authors.initials: RI
authors.lastname: Swift
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels / Q000473:pathology; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000000981:diagnostic imaging; D009367:Neoplasm Staging; D015588:Observer Variation; D011379:Prognosis; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed