Lycopene and survival in patients with stage III colon cancer: Findings from CALGB (Alliance)/SWOG 80702.

Abstract

3630 Background: Lycopene, a non-provitamin A carotenoid, has been reported to inhibit colon cancer development; however, its prognostic role after colon cancer diagnosis remains unknown. Given emerging evidence suggesting greater intake of lycopene-containing – particularly, tomato-based – foods may improve colon cancer prognosis, we assessed the association of postdiagnosis lycopene consumption with survival among 1666 patients (pts) with stage III colon cancer. Methods: Through an NCI-sponsored multicenter phase III adjuvant chemotherapy trial (CALGB/SWOG 80702; NCT01150045), we examined the consumption of total lycopene (dietary plus supplementation) and dietary lycopene as well as lycopene-containing foods (tomato-based foods plus other lycopene-containing foods) and tomato-based foods via validated food frequency questionnaires (FFQs) collected at 6 weeks after randomization (FFQ1) and again 14-16 months post-randomization (FFQ2). Lycopene-related exposures were calculated as time-varying measurements via cumulative averaging. Primary outcome was disease-free survival (DFS), defined as time from FFQ1 completion to colon cancer recurrence or death from any cause. Secondary outcomes were recurrence-free survival (RFS) and overall survival (OS). We estimated associations of lycopene-related exposures with survival via multivariable Cox proportional hazards regression. Results: In our cohort, pts with greater total lycopene intake tended to be slightly younger and of male sex and White race, have more left-sided tumors, and report higher caloric intake and physical activity engagement. Over median follow-up of 6.0 (IQR: 5.0-6.1) years, we observed 466 DFS, 395 RFS, and 300 OS events. Pts in the highest relative to lowest quintiles of total lycopene intake experienced significantly improved DFS (HR: 0.60 [95% CI: 0.44-0.83]; P trend =0.006), RFS (HR: 0.58 [95% CI: 0.41-0.82]; P trend =0.007), and OS (HR: 0.60 [95%CI: 0.40-0.89]; P trend =0.02). Similar findings were observed for dietary lycopene intake. Pts consuming >1 serving/day compared to 1 serving/week of all lycopene-containing foods did not experience significantly improved survival. However, when considering only tomato-based foods, we observed a trend toward improved survival (HR for DFS: 0.61 [95% CI: 0.38-0.96]; P trend =0.12). Conclusions: Greater lycopene consumption with or without supplementation was associated with lower risk of colon cancer recurrence and death which may be largely driven by tomato-based foods. Our findings may inform clinical nutrition recommendations for pts with colon cancer, with higher intake of tomato-based foods (>1 serving per day) potentially improving colon cancer survival. Future studies, especially interventional trials, are needed to validate our findings. Support: U10CA180821, U10CA180882, U24CA196171; Pfizer; https://acknowledgments.alliancefound.org.