Associations of WCRF/AICR recommendations with survival and chemotherapy outcomes in colon cancer: CALGB/SWOG 80702 (Alliance)

Background: Adhering to 2018 World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) Cancer Prevention Recommendations is reportedly associated with better survival among long-term colon cancer survivors (likely affected by immortal time bias). Thus, it is important to validate survival benefits by assessing adherence shortly after diagnosis, and further investigation is needed to examine its association with chemotherapy outcomes. Methods: Using an NCI-sponsored adjuvant chemotherapy trial conducted in patients with stage III colon cancer (CALGB/SWOG 80702; NCT01150045), we included 1,666 patients who returned valid Willett food frequency questionnaires (FFQ) at chemotherapy initiation and derived WCRF/AICR scores accordingly (higher score suggesting higher adherence). The primary outcome was disease-free survival (time from FFQ completion to recurrence or death), and secondary outcomes were reduced relative dose intensity (RDI; <85% suggesting worse completion) and severe toxicities (grade ≥3 for any chemotherapy-related toxicity). To estimate the associations of WCRF/AICR scores (quartiles) with survival and chemotherapy outcomes, we conducted multivariable Cox proportional hazards regression for disease-free survival and multivariable logistic regression for reduced RDI and severe toxicities. Results: Compared to those in the lowest quartile of the WCRF/AICR score, patients in the highest quartile had significantly better disease-free survival (hazard ratio: 0.75 [0.58, 0.98], P trend = 0.02) and lower risk of reduced RDI (odds ratio [OR]: 0.74 [0.54, 1.00], P trend = 0.03), but not for severe toxicities (OR: 1.24 [0.93, 1.67], P trend = 0.11). Conclusions: In patients with stage III colon cancer, higher adherence to WCRF/AICR recommendations was associated with better survival and chemotherapy completion, but not for severe toxicities. Funding : https://acknowledgments.alliancefound.org Table. Adjusted Associations of WCRF/AICR Recommendations with Survival and Chemotherapy Outcomes Survival and Chemotherapy Outcomes Q1 Q2 Q3 Q4 P trend Disease-free survival Number of events/at risk 133/393 134/492 74/323 114/458 Hazard ratio 1.00 0.83 (0.65, 1.05) 0.68 (0.51, 0.91) 0.75 (0.58, 0.98) 0.02 Reduced RDI Number of events/at risk 156/393 191/492 131/323 208/458 Odds ratio 1.00 0.97 (0.72, 1.30) 0.95 (0.69, 1.32) 0.74 (0.54, 1.00) 0.003 Severe toxicities Number of events/at risk 174/393 230/492 172/323 227/458 Odds ratio 1.00 1.10 (0.83, 1.46) 1.41 (1.03, 1.93) 1.24 (0.93, 1.67) 0.11