Abstract: Background and purpose: Lymph node metastasis of cervical cancer not only determines the prognosis, but also guides postoperative adjuvant therapy, and therefore it is of great significance to study the lymph node metastasis. This article aimed to evaluate the clinical value of squamous cell carcinoma antigen (SCCAg) combined with magnetic resonance imaging (MRI) in the diagnosis of pelvic lymph node metastasis of cervical squamous cell carcinoma. Methods: The clinical data of 110 patients with stage ⅠA-ⅡA cervical squamous cell carcinoma treated in our hospital from Jul. 2016 to Mar. 2018 were retrospectively analyzed. Statistical analysis was performed using SPSS 22.0 software. Results: The area under the receiver operating characteristic (ROC) curve of SCCAg to determine pelvic lymph node metastasis of cervical cancer in subjects was 0.695. The best critical value was 2.45 ng/mL, and 95%CI was 0.577-0.812. The positive predictive value was 46%，and the negative predictive value was 84%. The diagnostic accuracy was 71%，the sensitivity was 58.6%, and the specificity was 75.3% (Kappa=0.312, P=0.001). The positive predictive value of preoperative MRI in the diagnosis of pelvic lymph node metastasis in cervical squamous cell carcinoma was 77%. The negative predictive value was 89%. The accuracy rate was 86.4%.The sensitivity was 69.0%. The specificity was 92.60% (kappa=0.637, P=0.000). The positive predictive value of the combined diagnosis of pelvic lymph node metastasis of cervical squamous cell carcinoma was 55%, the negative predictive value was 97%, the accuracy was 78.1%, the sensitivity was 93.1%, and the specificity was 72.8% (Kappa=0.540, P=0.000). In univariate analysis, lymph node metastasis was associated with SCCAg>2.45 ng/mL, depth of interstitial infiltration, incision margin infiltration and vascular infiltration. Multivariate analysis showed that interstitial infiltration and vascular infiltration were independent risk factors for pelvic lymph node metastasis. Conclusion: Pelvic lymph node metastasis is associated with SCCAg>2.45 ng/mL, depth of interstitial invasion, incision margin infiltration and vascular infiltration. Especially when the interstitial infiltration and vascular infiltration are present, the possibility of lymph node metastasis could not be ignored. For the diagnosis of lymph node metastasis, MRI is superior to SCCAg. When SCCAg is combined with MRI, the sensitivity and negative predictive value can be significantly improved, which has important clinical significance for the diagnosis of cervical cancer without pelvic lymph node metastasis.

Key words: Cervical squamous cell carcinoma, Squamous cell carcinoma antigen, Magnetic resonance imaging, Lymph node metastasis