Incidence of cardiovascular events with fluoropyrimidines in gastrointestinal cancers

Objectives: There is limited data comparing the incidences of cardiac toxicities with fluoropyrimidines (FP) in patients with gastrointestinal cancers (GI). Material and Methods: Patients with GI cancers treated with infusional 5 FU (IFL), capecitabine (C) and S1 between January 2023 and December 2023 were retrieved from a prospectively maintained database at Tata Memorial Hospital (TMH) in Mumbai. Baseline demographic and clinical variables were evaluated. The primary endpoint of the study was estimation of all cardiac events in the study period and calculation of odds ratio (OR) for the relationship between baseline variables and the occurrence of all cardiac events. Major cardiac toxicities, was defined as cardiac abnormalities excluding asymptomatic self-limiting bradycardia or tachycardia. Results: A total of 2470 patients satisfied the inclusion criteria of the study, of whom 1342 patients (54%) received 5FU, 1071 received Cape (43%) and 55 received S1 (2%). Forty patients (1.6%) experienced a cardiac event, with the most common events being self-limiting bradycardia or tachycardia (15 events, 38%). The incidence of major cardiac toxicities was 1%. There were no differences in incidence of major cardiac events with IFL or C (1% each). The presence of hypertension [ 1.7% vs. 0.8%; OR - 2.27 (0.97–5.26) p = 0.06], diabetes mellitus [ 1.7% vs. 0.8%; OR - 2.38 (1.00–5.26), p = 0.051] and baseline cardiac dysfunction [ 3.1% vs. 0.9%; OR - 3.45 (1.00–11.1) p = 0.071] approached, but did not achieve statistical significance for the occurrence of major cardiac events. Conclusion: The incidence of cardiac abnormalities appears to be similar between IFL and capecitabine in patients with GI cancers. Cardiovascular comorbidities appeared to have weak correlation with the incidence of FP induced major cardiac events, highlighting the need for further research in this area of unmet need.