Rectal adenocarcinoma: proposal for a model based on pretreatment prognostic factors

Currently the choice of chemotherapy regimen in rectal cancer is made prior to surgery in contrast to colon cancer where it is made postoperatively after the pathological stage has been determined. If we could identify which are the important pretreatment prognostic factors in rectal cancer, we could then target those patients with unfavorable features to investigate potentially more effective preoperative chemotherapy regimens aimed at those with unfavorable features. The present study aimed to determine pre-treatment prognostic factors that are associated with an unfavorable outcome.

A retrospective review of 99 rectal cancer patients operated at the Auxilio Mutuo Hospital, San Juan, Puerto Rico, and the San Pablo Hospital, Bayamón, Puerto Rico was done. Socio-demographic, clinical and treatment data were collected.

Of the 99 cases, 54% were males. The mean age +/- standard deviation was 62.2 +/- 10.4. In age-adjusted Cox model, male gender (HR [95%CI]: 3.32 [1.09-10.13]), mucinous carcinoma (HR [95% CI]: 3.67 [1.25-10.77]), and clinical stages II & III (HR [95%CI]: 8.19 [1.08-62.08]) were predictors of poor prognosis. In the multivariate age-adjusted analysis, a tendency towards a poorer prognosis was observed for male patients (HR: 2.60), carcinoembryonic antigen level > or =5 ng/ml (HR: 2.55), mucinous carcinoma (HR: 2.96), and clinical stages II & III (HR: 4.96), although results were not statistically significant (p > 0.05).

Although current therapeutic results are relatively favorable with preoperative 5-fluorouracil and radiotherapy, future clinical trials should address the management of those cases with adverse pretreatment prognostic factors so that they can be treated with potentially more effective albeit more toxic chemotherapy regimens.