Elevated ¹⁸F-FDG uptake in non-metastatic lymph nodes of POLE-mutated endometrial cancer on PET/CT

DNA polymerase epsilon (POLE) exonuclease domain-mutated endometrial cancer (EC) is associated with a favorable prognosis and significant immune cell infiltration. Cancers with significant immune cell infiltration often exhibit higher maximum standardized uptake value (SUVmax) on ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT). This study aimed to evaluate the correlation between POLE status and FDG-PET/CT imaging in patients with EC.

This retrospective study enrolled 102 patients (mean age, 56.2 ± 11.8 years) with EC who underwent preoperative FDG-PET/CT between July 2018 and August 2023. Patients were categorized into molecular subtypes based on molecular profiling. SUVmax of the primary tumor and lymph nodes was measured, and correlations with molecular subtypes were examined.

The SUVmax in the primary tumor of POLE-mutated ECs was higher than that in non-POLE-mutated ECs (mean ± SD, 13.21 ± 4.78 vs 9.82 ± 3.78; p = 0.001). Multiple regression analysis showed that POLE status was associated with SUVmax in primary tumors (B = 2.30, p = 0.031). The SUVmax in non-metastatic lymph nodes of POLE-mutated ECs was higher than that in non-POLE-mutated ECs (median SUVmax, 1.31 [IQR, 1.05-2.21] vs. 1.06 [IQR, 0.91-1.20]; p = 0.003). Multiple regression analysis revealed that POLE status was the only factor associated with SUVmax in non-metastatic lymph nodes (B = 0.339, p = 0.046), while age, BMI, blood glucose level, histological type, and primary tumor size showed no significant association.

Patients with POLE-mutated EC exhibit high SUVmax in primary tumors and also tend to show elevated uptake in non-metastatic lymph nodes.