Prognostic value of the 2018 FIGO staging system for cervical cancer

OBJECTIVE: To compare the prognostic performance of the FIGO 2009 and FIGO 2018 staging systems for cervical cancer (CC) in regards to risk stratification, survival and treatment outcome.

METHODS: A total of 4461 CC patients diagnosed in Denmark during 2005-2018 were identified through the Danish Gynaecological Cancer Database and restaged from the 2009 FIGO to the 2018 FIGO staging system. 5-year survival estimates were made for each group. Also, association between lymphovascular space invasion (LVSI) and lymph node metastasis (LNM) was assesed for tumors with a horizontal spread >7 mm and depth of invasion ≤5 mm.

RESULTS: Overall, stage migration was observed in 41.4% of our cases due to the introduction of stage IIIC (20.1%), refined tumor size criteria within stage I (76.2%), and use of radiological findings to define stage IV (3.7%). 5-year overall survival increased for all stages except IA2, IIA2, IIIA and IIIB. Restaging of 2009 IB1 to 2018 FIGO resulted in significant stage allocations. Furthermore, an association between LVSI and LNM was observed in squamous cell carcinomas with a depth of invasion of 3-5 mm and a horizontal spread >7 mm (p = 0.03).

CONCLUSION: The 2018 FIGO staging system provided improved discriminatory ability for stage I and IV. Grouping all patients with positive pelvic or paraortal lymph nodes to stage IIIC led to pronounced heterogenous survival rates within these stages. Lymph node assessment was proven imperative in FIGO 2018 IA2 squamous cell carcinomas with a depth of invasion of 3-5 mm, a horizontal spread >7 mm and LVSI.