Randomized phase II trial of sulindac, atorvastatin, and prebiotic dietary fiber for colorectal cancer chemoprevention

Abstract

Sulindac, atorvastatin, or prebiotic dietary fiber may reduce colorectal cancer (CRC) risk. However, clinical trial data are currently limited. We conducted a randomized, phase II chemoprevention trial involving subjects 40 years or older, with previously resected colon cancer or multiple/advanced colorectal adenomas. Magnification chromoendoscopy (MCE) was performed to identify and characterize rectal aberrant crypt foci (ACF); eligibility criteria required five or more rectal ACFs at baseline. Intervention assignments were as follows: (a) atorvastatin 20 mg qd; (b) sulindac 150 mg bid; (c) oligofructose-enriched inulin (as ORAFTI®Synergy1) 6 gm bid; or (d) control (maltodextrin) 6 gm bid, for 6 months. Percent change in rectal ACF number (%ΔACF) within arm was the primary endpoint. Secondary endpoints included changes in proliferation (Ki67) and apoptosis (caspase-3), as measured from normal mucosa biopsy samples. Among 85 eligible randomized subjects, 76 (86%) completed the trial per protocol. The median (range) of rectal ACF was 9 (5-34) and 8 (0-37) at baseline and postintervention, respectively. The median (SD) for %ΔACF was 5.6 (-69% to 143%), -18.6 (-83% to 160%), -3.6 (-88% to 83%), and -10.0 (-100% to 117%) in the atorvastatin, sulindac, ORAFTI®Synergy1 and control arms, respectively. Neither within-arm (P = 0.12-0.59) nor between-arm (P = 0.30-0.92) comparisons of %ΔACF were statistically significant. The active and control interventions also seemed to have similar effects on mucosal proliferation and apoptosis (P > 0.05 for each comparison). Data from this multicenter, phase II trial do not provide convincing evidence of CRC risk reduction from 6-month interventions with atorvastatin, sulindac, or ORAFTI®Synergy1, although statistical power was limited by the relatively small sample size.

Figure 1

Representative image of rectal aberrant crypt foci (ACF) detected by magnification chromoendoscopy.

Figure 2

CONSORT overview of subject recruitment.

Figure 3

Change in proliferation (Ki67), by intervention arm. Based on biopsy samples from normal-appearing rectal mucosa obtained during the pre-intervention (baseline) and post-intervention evaluations. Box and whisker plot, demonstrating median, interquartile range, and extreme values; mean value also represented (+). Arm A: atorvastatin 20 mg tablet once per day; Arm B: sulindac 150 mg tablet twice per day; Arm C: ORAFTI^®Synergy1 6 gm powder twice per day; Arm D: control (maltodextrin powder) twice per day.

Figure 4

Change in apoptosis (caspase-3), by intervention arm. Based on biopsy samples from normal-appearing rectal mucosa obtained during the pre-intervention (baseline) and post-intervention evaluations. Box and whisker plot, demonstrating median, interquartile range, and extreme values; mean value also represented (+). Arm A: atorvastatin 20 mg tablet once per day; Arm B: sulindac 150 mg tablet twice per day; Arm C: ORAFTI^®Synergy1 6 gm powder twice per day; Arm D: control (maltodextrin powder) twice per day.