Redistribution of cervix cancer patients from FIGO 2009 to FIGO 2018 staging following incorporation of medical imaging

Objectives: The aim of this study was to quantify the shift in patients from the FIGO 2009 to the FIGO 2018 staging using a prospectively collected dataset where pre-treatment MRI and PET-CT were used. A secondary aim was to explore the distribution of known prognostic factors in both staging schema. Methods: Prospectively collected dataset of 1047 cervix cancer patients staged with MRI and PET-CT, between 1996 and 2014, were redistributed using FIGO 2018 staging criteria. Standard deviation inter-quartile and contingency tables were used to present the distribution of patients according to FIGO 2009 and FIGO 2018 criteria. Logistic regression was used to evaluate the association of node positivity and nodal size. Results and Discussion: In total, 853 patients were available for analyses. Based on MRI and PET findings, according to FIGO 2009, the incidence of lymph node metastasis was similar in (1) stages 1b1 and 2a1, (2) 1b, 2a2, 2b and 3a (3) 3b and 4a. Nodal metastases were found in 43% patients who were upstaged from FIGO 2009 to newly created FIGO 2018 stages 3c1 and 3c2. Contribution to stage 3c1 came from 31, 41, 29, 30, 32, 33 and 34% of stages 1b1, 1b2, 2a1, 2a2, 3a and 3b, respectively. FIGO 2009 stages 1b1 and 1b2 contributed 5 and 6%, stages 2a1, 2a2, 2b and 3a contributed 16, 15 and 15% to para-aortic nodes, while stage 3b contributed 24%. These findings will likely influence cervix cancer treatment policies