title: Time to loco-regional recurrence after resection of Dukes' B and C colorectal cancer with or without adjuvant postoperative radiotherapy. A multivariate regression analysis.
abstract: Factors influencing time to loco-regional recurrence were identified in a multivariate regression analysis of data from a series of 468 radically operated patients (260 Dukes' B and 208 Dukes' C) with carcinoma of the rectum and the rectosigmoid. A number of clinical and pathological characteristics were prospectively collected and recorded. In addition, carcinoembryonic antigen (CEA) was measured within 1 week before surgery. The endpoint used was recurrence below the level of the umbilicus. All patients were followed for at least 5 years or until time of death. The two Dukes' stages B and C were analysed in two separate analyses using the Cox proportional hazards model. In patients with Dukes' B tumours, an increased risk of loco-regional recurrence was associated with perineural invasion, tumour located less than 10 cm from the anal verge, patient aged above 70 years, and small tumour size. In patients with Dukes' C tumours, the necessity to resect neighbour organs, perineural and venous invasion, tumour located less than 10 cm from the anal verge, and large tumour size were all associated with a poor loco-regional outcome. Postoperative radiotherapy was not a significant prognosticator for loco-regional control. An update of the 5-year results of the randomised study of post-operative radiotherapy (50 Gy with 2 Gy per fraction in an overall treatment time of 7 weeks) showed no survival benefit from adjuvant radiotherapy in either Dukes' category and no statistically significant improvement in the 5-year loco-regional control rate. However, when the comparison was restricted to a group of high-risk patients there was a statistically significant benefit from radiotherapy with respect to loco-regional control (P = 0.03) but not with respect to survival (P = 0.23). The potential advantage, in terms of the required number of patients, of restricting clinical trials of intensified loco-regional therapies to the high-risk patients, is illustrated.
authors.affiliation: Danish Cancer Society, Department of Experimental Clinical Oncology, Aarhus C.
authors.forename: S M
authors.initials: SM
authors.lastname: Bentzen
authors.forename: I
authors.initials: I
authors.lastname: Balslev
authors.forename: M
authors.initials: M
authors.lastname: Pedersen
authors.forename: P S
authors.initials: PS
authors.lastname: Teglbjaerg
authors.forename: F
authors.initials: F
authors.lastname: Hanberg-Sørensen
authors.forename: J
authors.initials: J
authors.lastname: Bone
authors.forename: N O
authors.initials: NO
authors.lastname: Jacobsen
authors.forename: A
authors.initials: A
authors.lastname: Sell
authors.forename: J
authors.initials: J
authors.lastname: Overgaard
authors.forename: K
authors.initials: K
authors.lastname: Bertelsen
mesh_terms: D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D012008:Recurrence; D012044:Regression Analysis; D013997:Time Factors