Objective:To study the significance and mechanism of miR-21, interleukin-6, interleukin-17 in the diagnosis of endometrial cancer.Methods:A retrospective analysis was condueted on the clinical data of 40 endometrial cancer patients and 40 healthy volunteers admitted to Lianyungang Second People's Hospital from March 2020 to March 2023. Real time fluorescence quantitative PCR was used to detect serum miR-21 levels and enzyme-linked immunosorbent assay was used to detect serum interleukin-6 and interleukin-17 levels in both groups.Results:The serum levels of interleukin-17 [(37.22 ± 13.08) ng/L], interleukin-6 [(12.09 ± 3.99) ng/L], and miR-21 [(2.83 ± 0.93)] in the endometrial cancer group were significantly higher than those in the normal control group [(15.72 ± 8.96) ng/L, (3.93 ± 2.19) ng/L, (1.20 ± 0.39), respectively] ( t = 8.58, 11.34, 10.20, all P < 0.001). Pearson correlation analysis showed that there was a significant positive correlation between serum interleukin-17 and interleukin-6 levels in patients with endometrial cancer ( r = 0.97, P < 0.001), between interleukin-17 level and miR-21 expression in patients with endometrial cancer ( r = 0.96, P < 0.001), and between interleukin-16 level and miR-21 expression in patients with endometrial cancer ( r = 0.99, P < 0.001). Receiver operating characteristic curve analysis showed that when the cut-off value of interleukin-17 was 21.65 ng/L, the sensitivity of the diagnosis of endometrial cancer was 80%, the specificity was 87.5%, and the area under the curve was 0.894 [95% confidence interval ( CI) = 0.827-0.961, P < 0.001]; when the cut-off value of interleukin-6 was 7.44 ng/L, the diagnostic sensitivity was 85.0%, the specificity was 92.5%, and the area under the curve was 0.959 (95% CI = 0.923-0.995, P < 0.001); when the cut-off value of miR-21 was 1.85, the diagnostic sensitivity was 77.5%, the specificity was 92.5%, and the area under the curve was 0.947 (95% CI = 0.905-0.989, P < 0.001). Conclusion:This study confirmed that serum interleukin-17, interleukin-6, and miR-21 could potentially serve as early predictors of endometrial cancer to a certain extent. The combined evaluation of these three parameters may be more valuable for diagnosis.