Introduction/Background The depiction of treatment approaches in ovarian cancer is usually based on common histological subtypes. Rare subtypes, such as low-grade serous, mucinous and low-grade endometrioid cancers are usually underrepresented in all-comer studies. In this study, we scrutinized the predictive value of AGO score in anticipating complete tumour resection for less common subtypes of ovarian cancer. We defined our aims as twofold: 1) Can we apply the AGO score in predicting complete cytoreduction for recurrent low-grade cancers? 2) If not, how can we identify the right patients as ideal candidates for surgery?

Methodology Data of patients with grade 1 serous and grade 1–2 endometrioid and mucinous ovarian cancers who underwent cytoreductive surgery for recurrent disease between 01/2001 and 04/2023 were reviewed, and 77 recurrences were eligible for the study analysis. Multivariate proportional odds models were used to identify factors.

Results Complete cytoreduction was achieved in 31 of 55 (56.3%) patients in surgery for the first recurrence and in 41(53.2%) of all recurrences. The PPV of positive AGO score for complete resection in the first recurrence was 66.7 (95% CI:47.3–81.7%) (p=0.117), and it was 72% (95% CI:55.2–84.3%) (p=0.008) for all recurrences.

Only 7.8% of patients presented with an ascites volume of >500ml.

Univariate analysis revealed that FIGO-stage (p=0.01), treatment-free interval (p=0.023), CA-125 (p=0.013) in all recurrences, and ascites (p=0.028) in the first recurrence are associated with complete cytoreduction. However, logistic regression revealed that none of these factors has an independent and significant impact on the probability of achieving complete resection.

Conclusion Our analysis showed that AGO score is not suitable for anticipating complete cytoreduction in the first and subsequent recurrences of low-grade cancers. None of the factors constituting the AGO score reached independent significance in predicting complete resection. We could also not introduce further criteria for optimal selection of these patients, hence patient selection remains at the clinician’s discretion in recurrent low-grade cancers.

Disclosures No.