Minimal effect of the initial tumor stage on follow-up intensity for rectal cancer patients after curative-intent treatment

Introduction: For rectal cancer patients, the risk of recurrence after curative-intent treatment is directly related to initial tumor stage. It is often assumed that more intensive follow-up is worthwhile in patients with high tumor-node-metastasis (TNM) stage lesions, while less intensive follow-up is sufficient for those with low TNM stage cancers. We surveyed the 1,795 members of the American Society of Colon and Rectal Surgeons (ASCRS) to determine the surveillance strategies they use after primary curative-intent treatment for their own patients. This report describes the variation in surveillance intensity ascribable to initial TNM stage.

Methods: We created a series of 4 vignettes succinctly describing generally healthy patients with rectal carcinoma (stage I treated with local excision, stage I treated with radical surgery, stage II treated with radical surgery, and stage III treated with radical surgery ± adjuvant therapy). We mailed a questionnaire based on the vignettes to all ASCRS members. Evaluable replies were entered into a computer database. The effect of TNM stage on follow-up intensity was analyzed using repeated-measures ANOVA.

Results: There were 566 responses (32%), among which 347 (61%) were evaluable. The most frequent surveillance modality was office visit. In post-operative year 1 for patients with stage I lesions treated with local therapy, 3.8 ± 1.4 office visits (mean ± SD) were recommended, decreasing to 1.5 ± 0.8 in year 5. For patients with stage III lesions treated with radical surgery ± adjuvant therapy, 4.0 ± 2.8 office visits were recommended in year 1, decreasing to 1.7 ± 1.2 in year 5. Similar results were generated for all commonly used modalities on the questionnaire (3 blood tests, 2 endoscopic procedures, 8 imaging studies).

Conclusions: The intensity of post-operative surveillance following curative-intent treatment for rectal cancer varies minimally by TNM stage. Because of this, a randomized trial of alternate follow-up strategies may be feasible without stratification according to stage. We will present the schema of such a trial at the meeting.