Understanding surgeon decision making in the use of radiotherapy as neoadjuvant treatment in rectal cancer

Substantial evidence supports the use of neoadjuvant radiotherapy in the management of resectable rectal cancer to improve local control. Decision making however, is complex, with multiple available treatment choices, varying influence of both clinical and non-clinical factors and, ever changing evidence resulting in uncertainty. There is a paucity of research investigating clinician decision making in rectal cancer. This research aimed to determine the effect of clinical and non-clinical factors on decision making by colorectal surgeons in patients with rectal cancer. Two factorial surveys comprising clinical vignettes of alternating short (4) and long (12) cues identified previously as important in rectal cancer treatment decision making, were randomly assigned to all members of the Colorectal Surgical Society of Australia and New Zealand. Respondents chose from three possible treatments: long course chemoradiotherapy (LC), short course radiotherapy (SC), or surgery alone to investigate the effects on surgeon decision and confidence in decisions. Choice data were analysed using multinomial logistic regression models. The response rate was 64% (106/165). LC was the preferred treatment choice in 73% of vignettes. Surgeons were more likely to recommend LC over SC (OR 1.79) or surgery alone (OR 1.99) when presented with shorter, four-cue scenarios. There was no significant difference in confidence in the decision made when surgeons were presented with long-cue vignettes (p = 0.57). Significant factors affecting choice between LC, SC and surgery alone were tumour stage (p < 0.001), nodal status (p < 0.001), tumour position in the rectum (p < 0.001) and the circumferential location of the tumour (p < 0.001). A T4 tumour was the factor most likely associated with a recommendation against surgery alone (OR 335.96) or SC (OR 61.73). These results demonstrate that clinical factors exert the most significant influence on Australian and New Zealand surgeon decision making. Therapy is primarily determined by tumour stage, position, circumferential location and nodal stage. LC is the preferred treatment of choice. Surgeon decision making appears to follow a ‘fast and frugal’ heuristic decision making model