Outcome Analysis of Cytoreductive Surgery and Hyperthermic Intrathoracic Chemoperfusion (HITHOC) for Pseudomyxoma Peritonei with Pleural Metastasis.

Abstract

Although cytoreductive surgery (CRS) and hyperthermic intrathoracic chemoperfusion (HITHOC) are used to treat primary pleural malignancies, their role in managing pleural metastases from pseudomyxoma peritonei (PMP) remains underexplored. This study evaluated the role of CRS/HITHOC on outcomes of PMP with pleural involvement. We conducted a single-institution, retrospective analysis of patients with PMP who underwent CRS/hyperthermic intraperitoneal chemotherapy (HIPEC) between 2008 and 2022. Perioperative and oncologic outcomes between patients with metachronous or synchronous pleural metastases were compared between those treated with and without CRS/HITHOC. A total of 814 patients with PMP underwent CRS/HIPEC during the study period. In total, 64 patients (7.9%) developed pleural metastases (8 synchronous and 56 metachronous), with a median pleural recurrence interval of 15.6 months (interquartile range (IQR) = 6.8-26.6 months). Of these, 20 patients received CRS/HITHOC as part of multimodal management. There was no significant difference in median age between groups (52 versus 56 years; p = 0.602), though the CRS/HITHOC group trended toward fewer preceding recurrences at other sites (35.0% versus 43.2%; p = 0.593). All 20 patients undergoing HITHOC had pleurectomy and decortication; there was no 30-day mortality. The HITHOC group demonstrated a trend toward improved OS after pleural recurrence (58.5 versus 16.4 months; p = 0.063) and had a longer survival from the time of initial HIPEC (106.0 versus 42.9 months; p = 0.015) in this cohort. Incorporating HITHOC into the management of PMP with pleural involvement was associated with improved survival and may represent an effective strategy for both the treatment and palliation of pleural metastases in PMP.