Correlation of several forms of folic acid with endometrial cancer: cross-sectional data from the National Health and Nutrition Examination Surveys (NHANES) 2011-2018

Abstract Objective Endometrial cancer (EC) is a common malignancy of the female reproductive system and although most patients have a good prognosis, 20–30% of patients with advanced disease have a poor prognosis. There are currently no reliable biomarkers for early diagnosis and effective prognostic improvement of the disease. The aim of this study was to explore the effect of folic acid on the occurrence of EC and its clinical application using the National Health and Nutrition Examination Survey (NHANES) database. Methods This study included 8,809 female subjects aged ≥ 20 years in the NHANES database from 2011–2018, including 8,738 non-oncology patients and 71 EC patients. Reduced selection bias using 1:1 propensity score matching (PSM) method. Restricted cubic spline (RCS) was plotted to explore the non-linear relationship between different forms of folic acid and EC. Result Using data from the NHANES database from 2011–2018 to assess the association between folic acid and the risk of developing EC. The results of the 1:1 ratio propensity score matching (PSM) showed 68 each for EC patients and non-oncology participants. Total serum folate, 5-methyltetrahydrofolate (5-methylTHF), 5-formyltetrahydrofolate (5-formylTHF), tetrahydrofolate (THF) and 5,10-methylenetetrahydrofolate (5,10-methenylTHF) were significantly correlated with EC ( p < 0.05). In addition, the RCS showed a significant non-linear correlation between THF and 5,10-formyl THF and the risk of developing EC. Conclusion The results of this study showed that changes in serum total folate, 5-methylTHF, 5-formylTHF, THF and 5,10-methenylTHF were closely related to EC.