Intake and biomarkers of folate and folic acid as determinants of chemotherapy-induced toxicities in patients with colorectal cancer: a cohort study.

BACKGROUND: Capecitabine is an oral chemotherapeutic drug showing antitumor activity through inhibition of thymidylate synthase, an enzyme involved in folate metabolism. There are concerns about the high intake of certain vitamins, and specifically folate, during chemotherapy with capecitabine. Whether folate or folic acid, the synthetic variant of the vitamin, impact treatment toxicity remains unclear. OBJECTIVE: We studied associations between intake and biomarkers of folate as well as folic acid and toxicities in patients with colorectal cancer (CRC) receiving capecitabine. METHODS: Within the prospective COLON (Colorectal cancer: Longitudinal, Observational study on Nutritional and lifestyle factors that influence recurrence, survival, and quality of life) cohort, 290 patients with stage II to III CRC receiving capecitabine were identified. Dietary and supplemental intake of folate and folic acid were assessed at diagnosis and during chemotherapy using questionnaires (available for 280 patients). Plasma folate and folic acid levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) and were available for 212 patients. Toxicities were defined as toxicity-related modifications of treatment, including dose reductions, regimen switches, and early discontinuation. Associations of intake and biomarkers of folate and folic acid with toxicities were determined using Cox proportional hazards regression adjusted for age and sex. RESULTS: In total, 153 (53%) patients experienced toxicities leading to modification of capecitabine treatment. Folate intake and plasma folate levels were not associated with risk of toxicities. However, use of folic acid-containing supplements during treatment (hazard ratio (HR) 1.81 and 95% confidence interval (CI) 1.15-2.85) and presence of folic acid in plasma at diagnosis (HR 2.09, 95% CI: 1.24, 3.52) and during treatment (HR 2.31, 95% CI: 1.29, 4.13) were associated with an increased risk of toxicities. CONCLUSIONS: This study suggests a potential association between folic acid and capecitabine-induced toxicities, providing a rationale to study diet-drug interactions and raise further awareness of the use of dietary supplements during oncological treatment. CLINICAL TRIAL DETAILS: This trial was registered at clinicaltrials.gov as NCT03191110.

Postdiagnostic intake of a more proinflammatory diet is associated with a higher risk of recurrence and all-cause mortality in colorectal cancer survivors.

BACKGROUND: The inflammatory potential of the diet has been associated with colorectal cancer (CRC) risk, but its association with CRC prognosis is unclear. OBJECTIVE: To investigate the inflammatory potential of the diet in relation to recurrence and all-cause mortality among persons diagnosed with stage I to III CRC. METHODS: Data of the COLON study, a prospective cohort among CRC survivors were used. Dietary intake, 6 mo after diagnosis, was assessed by using a food frequency questionnaire and was available for 1631 individuals. The empirical dietary inflammatory pattern (EDIP) score was used as a proxy for the inflammatory potential of the diet. The EDIP score was created by using reduced rank regression and stepwise linear regression to identify food groups that explained most of the variations in plasma inflammatory markers (IL6, IL8, C-reactive protein, and tumor necrosis factor-α) measured in a subgroup of survivors (n = 421). Multivariable Cox proportional hazard models with restricted cubic splines were used to investigate the relation between the EDIP score and CRC recurrence and all-cause mortality. Models were adjusted for age, sex, BMI, PAL, smoking status, stage of disease, and tumor location. RESULTS: The median follow-up time was 2.6 y (IQR: 2.1) for recurrence and 5.6 y (IQR: 3.0) for all-cause mortality, during which 154 and 239 events occurred, respectively. A nonlinear positive association between the EDIP score and recurrence and all-cause mortality was observed. For example, a more proinflammatory diet (EDIP score +0.75) compared with the median (EDIP score 0) was associated with a higher risk of CRC recurrence (HR: 1.15; 95% CI: 1.03, 1.29) and all-cause mortality (HR: 1.23; 95% CI: 1.12, 1.35). CONCLUSIONS: A more proinflammatory diet was associated with a higher risk of recurrence and all-cause mortality in CRC survivors. Further intervention studies should investigate whether a switch to a more anti-inflammatory diet improves CRC prognosis.