External validation of the Annual Recurrence Risk Model (ARRM) for tailored surveillance strategy in patients with cervical cancer

Objective: The annual recurrence risk model (ARRM), developed by the Surveillance in Cervical Cancer consortium and endorsed by the European Society of Gynecological Oncology, predicts the annual risk of cervical cancer recurrence. However, it lacks an external validation, which we aimed to address in the current retrospective study. Methods: We included patients with pathology confirmed T1a to T2b cervical cancers who underwent radical surgery at the European Institute of Oncology, Milan from January 2010 to December 2022. Using the ARRM risk calculator, patients were assigned a score from 0 to 100 points, which allowed classification into 5 risk groups (0, 1-25, 26-50, 51-75, and 76-100 points). Differences in 5-year disease-free survival were evaluated through log-rank tests with pairwise comparisons. Annual risk of recurrence was calculated using conditional survival analysis. Results: Overall, 411 patients with cervical cancers were included: 0 (0.0%) scored 0 points, 149 (36.3%) scored 1 to 25 points, 224 (54.5%) scored 26 to 50 points, 37 (9.0%) scored 51 to 75 points, and 1 (0.2%) scored 76 to 100 points. The patient from 76 to 100 points was excluded from further analyses. The 5-year disease-free survival rates were 96.3% (95% CI 90.0 to 98.6), 85.7% (95% CI 80.1% to 89.9%), and 66.6% (95% CI 47.3% to 80.2%) in groups 1 to 25, 26 to 50, and 51 to 75 points, respectively (p < .01). Compared with 26 to 50 and 51 to 75 points, the annual risk of recurrence was lower in the 1 to 25 points group, at around 1% from year 1 to 5. Conclusions: The ARRM tool confirmed its validity in stratifying cervical cancer into groups with significantly different disease-free survival rates in an independent large population from a tertiary center. The annual risk of recurrence should be carefully considered when tailoring follow-up, always taking into account the patient's perspective.