Introduction/Background One of the possible manifestations of extraabdominal disease in ovarian cancer patients at FIGO stage IVB is cardiophrenic lymph nodes (CPLN) involvement. However, its prognostic impact and the best approach are still unclear.

In this study, we aimed to evaluate the prognosis of patients with resolved CPLN metastases after neoadjuvant chemotherapy (NACT).

Methodology Retrospective case-control study including consecutive patients diagnosed with unresectable ovarian high-grade serous carcinoma (HGSC) undergoing interval surgery at a tertiary oncology center from 2017 to 2022.

Characteristics and clinical outcomes were compared between two groups: Group 1 (cases) - patients with CPLN metastases (stage IVB) that resolved after NACT; and Group 2 (controls) - patients with an initial stage IIIC.

In Group 1, CPLN metastases were the sole extraabdominal manifestation, identified by a short axis of ≥5mm or an increased number on pretreatment computed tomography.

Results Analysis included 31 patients (Group 1: 14, Group 2: 17).

At diagnosis, patients in Group 1 were younger (61.5 vs 69.0 years, p=0.010) and exhibited more abdominal and pelvic lymph nodes metastases (72.7% vs 31.3%, p=0.034).

No significant differences were found in peritoneal cancer index, upper abdominal metastases or ascites, at diagnosis or in perioperative evaluation.

In Group 1, optimal cytoreduction was more frequent (85.7% vs 58.8% p=0.132), but with a higher recurrence rate (55.6% vs 33.3%, p=0.608). However, recurrences occurred later (19.3 vs 13.1 months, p=0.053) and overall survival (OS) showed no significant difference between groups.

Conclusion In our series, patients with CPLN involvement presented with more abdominal and pelvic lymph nodes metastases, but showed similar upper abdominal disease.

Despiste higher recurrence rates, patients with resolved CPLN metastases exhibited superior disease-free survival, with no difference in OS.

The main limitation is the very small sample size. Further discussion is important for a comprehensive understanding of the significance of resolving CPLN metastases after NACT.

Disclosures No disclosures.