Management of significant pleural effusion at ovarian cancer diagnosis: Outcomes of triage to neoadjuvant chemotherapy without thoracic assessment.

Objectives: Management of epithelial ovarian cancer presenting with moderate to large pleural effusion at first diagnosis is a clinical challenge. Several options are utilized with limited evidence including initial thoracoscopic evaluation, neoadjuvant chemotherapy (NACT) or some combination. We sought to evaluate the disease course and patterns of recurrence after triage to NACT. Methods: We included all clinical Stage IVA patients having moderate to large pleural effusions without radiologic evidence of a Stage IVB metastasis presenting to our institution between 2016 and 2021. Clinical outcomes and patterns of recurrence were evaluated using descriptive statistics and Kaplan-Meier curves. Results: There were 31 patients (7.5 % of new ovarian cancer cases) who met inclusion criteria with median age 68.0 years. Most had high grade serous histology (29; 93.5 %) and 3/27 (11.1 %) were BRCA positive. Factors influencing triage to NACT were effusion alone in 3 (9.7 %) patients whereas 14/31 (45.2 %) had ≥2 factors. Resolution of the effusion occurred after NACT alone in 23 (74.2 %). Eight patients never proceeded to surgery. Complete gross resection (CGR) of abdominal disease at interval debulking surgery (IDS) was achieved in 14/23 (60.9 %), residual disease (RD) ≤1 cm in 8/23 (34.8 %) and >1 cm in 1/23 (4.3 %). Chemotherapy response scores were available for 19/23 cases and did not correlate with survival. After IDS, all patients received adjuvant platinum-based chemotherapy for a median of 3 cycles and 4 patients received maintenance therapy (PARP inhibitor in 4, bevacizumab in 1). Median OS for the whole cohort was 30.5 months: 3-year OS was 0 % if no surgery (8 patients), 27.8 % if any visible disease after IDS (9 patients), and 71.4 % if CGR (5-year OS 64.3 %). Recurrence or progression occurred in 30/31 distributed as follows: abdomen alone (16/30, 53.3 %) versus abdomen and thorax (13/30, 41.9 %). Only 1 patient recurred in the thorax alone. Conclusions: Limited evidence directs the best management for patients presenting with clinical Stage IVA disease. Our data represent a particularly high-risk subgroup which may be characteristic of patients with large pleural effusions and adds important information showing that approximately half of these patients have ≥2 indications to favor NACT, signifying their high-risk status. Despite this, when CGR in the abdomen was achieved at IDS, median OS was greater than 5 years.