Decision analysis as an aid to determining the management of early low rectal cancer for the individual patient

Abstract

Purpose: Because there are no data available from randomized controlled trials (RCT), a decision analysis was performed to aid in the decision of which option, a local excision with or without radiotherapy or an abdominal perineal resection (APR), should be offered to medically fit patients with early (suspected T1/T2) low (< 5 cm) rectal cancer.

Methods: All clinically relevant outcomes, including complications of surgery and radiotherapy, cure, salvageability after local recurrence, distant disease, and death, were modeled for both options. The probabilities of complications and outcomes after radiotherapy and/or local excision were derived from weighted averages of results from studies conducted between 1969 and 1997. The probabilities for the APR option were extracted from relevant RCTs. Long- and short-term patient-centered utilities for each complication and outcome were extracted from the literature and from expert opinion.

Results: The expected utility of local excision (EU = 0.81) for the base case was higher than the expected utility for APR (EU = 0.78). Although the result was sensitive to all variables, local excision was always favored over APR within the plausible ranges of the variables taken one, two, or three at a time. The model illustrated the tension between the patient's perception of a colostomy and the higher recurrence rates with local excision.

Conclusion: The results of this decision analysis suggest that local therapy for early low rectal cancer is the preferred method of treatment. However, there must be careful preoperative assessment, patient selection, and consideration of patient concerns. In addition, decision analysis may be useful in providing patient information and assisting in decision making.