Risk factors for lymph node metastasis in women with FIGO 2018 IA cervical cancer with a horizontal spread of > 7 mm.

Background: In the FIGO 2018 classification, women with cervical cancer and a depth of invasion ≤ 5 mm and a horizontal spread of > 7 mm in excisional biopsy with tumour-free margins, are now classified as stage IA instead of IB. This stage shift may reduce the likelihood of surgical lymph node staging. It is therefore crucial to estimate the risk and risk factors of lymph node metastasis (pN+) in this group.

Methods: Women diagnosed with cervical cancer between 2005 and 2022 were identified from nationwide population-based registries from the Netherlands, Denmark, and Sweden. Inclusion criteria were squamous cell carcinoma or adenocarcinoma, FIGO 2009 stage IB1, a depth of invasion ≤ 5 mm and horizontal spread of > 7-≤ 40 mm. All cases underwent radical hysterectomy or radical trachelectomy, and surgical lymph node staging. Logistic regression was used to identify risk factors of pN+.

Results: We included 992 women (pN+ 4.1 %; n = 41). Lymphovascular space invasion (LVSI) was a significant risk factor of pN+ (odds ratio 4.26, 95 % confidence interval 2.24-8.32). Accordingly, the risk of pN+ was ≥ 7.3 % in LVSI-positive tumours. The risk was lowest in LVSI-negative tumours with a size of > 7-≤ 20 mm (2.2 %), although this varied by depth of invasion and histological subtype (pN+ range 0.6-5.1 %).

Conclusion: Women with LVSI-positive FIGO 2018 IA cervical cancer and a horizontal spread > 7 mm, should undergo surgical lymph node staging. In LVSI-negative tumours, lymph node staging should not be routinely performed; tumour size, depth of invasion and histology should be considered.