A regression analysis of prognostic factors after resection of Dukes' B and C carcinoma of the rectum and rectosigmoid. Does post-operative radiotherapy change the prognosis?
The prognostic value of several clinical and histopathological characteristics has been evaluated in patients with Dukes' B and C carcinoma of the rectum and the rectosigmoid. Data on 260 Dukes' B and 208 Dukes' C tumours entered into a prospective, randomized clinical trial of post-operative radiotherapy (50 Gy given with 2 Gy/fraction in an overall time of 7 weeks) were analyzed by means of the Cox proportional hazards model. The Dukes' stages B and C were analyzed in two separate multivariate analyses. In patients with Dukes' B tumours, a poor prognosis was associated with age above 60, perineural and venous invasion, tumour located less than 10 cm from the anal verge and elevated pre-operative carcinoembryonic antigen (CEA) (greater than 3.2 ng ml-1). In patients with Dukes' C tumours, perineural and venous invasion, tumour located less than 10 cm from the anal verge, and elevated pre-operative CEA were associated with a poor prognosis. In addition, a large tumour diameter had a strong, negative influence on the prognosis. Males seemed to have a poorer prognosis than females among the Dukes' C patients. Resection of neighbouring organs was also associated with a poor prognosis in this stage. Post-operative radiotherapy as administered in the present series had no significant influence on prognosis. Based on the derived prognostic models patients with a hazard of death above the median in each stage were selected. A separate analysis of the survival in these high risk patients showed no survival benefit from radiotherapy. The proportional hazards model may be a useful tool in selecting patients for more aggressive adjuvant treatment.
Bentzen
S M
SM
Radiophysics Laboratory, Radiumstationen, Aarhus.
Balslev
I
I
Pedersen
M
M
Teglbjaerg
P S
PS
Hanberg-Soerensen
F
F
Bone
J
J
Jacobsen
N O
NO
Overgaard
J
J
Sell
A
A
Bertelsen
K
K
D000367:Age Factors; D000368:Aged; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011379:Prognosis; D012004:Rectal Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery*; D012737:Sex Factors; D012811:Sigmoid Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery*
D002272:Carcinoembryonic Antigen