The risk of lymph node metastasis in the new FIGO 2018 stage IA cervical cancer with >7 mm diameter

OBJECTIVE: In the 2018 FIGO staging system, cervical cancers with ≤5 mm depth of invasion (DOI) and a diameter of >7 mm, first classified as stage IB, are classified as stage IA. In this group, it is unclear what the risk of lymph node metastasis (LNM) is. This retrospective cohort study aims to determine the incidence of LNM and to study the association between disease-related characteristics and LNM. METHODS: Women diagnosed with FIGO 2009 IB cervical cancer, with ≤5 mm DOI and a diameter >7 mm, treated with a radical hysterectomy and pelvic lymphadenectomy between 1985 and 2020 were selected from the databases of the Amsterdam University Medical Center and the University Medical Center Groningen. The specimens of patients with LNM were revised by expert pathologists. The incidence of LNM was calculated. The associations between LNM and DOI, diameter, histological type, clinical visibility and lymphovascular space invasion (LVSI) were evaluated by calculating odds ratios using logistic regression. RESULTS: Of the 389 patients included, 10 had pathologically confirmed LNM (2.6%, 95% confidence interval=1.3%-4.5%). In case of LVSI, univariate analysis showed an increased risk of LNM (p=0.003 and p=0.012, respectively). No difference in LNM was found between lesions diagnosed by microscopy and clinically visible lesions. No LNM were found in patients without LVSI and a DOI of ≤3 mm. CONCLUSION: For patients with stage IA cervical cancer with a diameter >7 mm, we recommend considering a pelvic lymph node assessment in case of DOI >3 mm and/or presence of LVSI.