Hyperthermic intrathoracic chemotherapy after cytoreductive surgery in malignant pleural mesothelioma: a single-center retrospective cohort study suggesting increased morbidity without survival benefit.

BACKGROUND

In the multimodal treatment of pleural mesothelioma (PM), hyperthermic intrathoracic chemotherapy (HITOC) has been investigated as an adjunct to cytoreductive surgery (CRS) to potentially improve local tumor control. The study aimed to evaluate the clinical impact of HITOC as an adjunct to CRS, specifically regarding overall survival (OS), postoperative morbidity and mortality, and operative duration.

METHODS

This retrospective study compared patients who underwent CRS with HITOC to those without HITOC at our institution between 2010 and 2022. Primary endpoints included OS, operative time, and perioperative morbidity and mortality. Categorical variables were compared using the Fisher's exact test. Survival analyses were performed using the Kaplan-Meier method and compared via the log-rank test.

RESULTS

A total of 114 patients underwent CRS for PM, including 14 with HITOC and 100 without. The mean age was 66 years, and 12 patients were female. The mean operative time was longer in the HITOC group (488 vs. 258 minutes). Postoperative morbidity (Clavien-Dindo Grade ≥ III) was significantly higher with HITOC [43 % vs. 10 %, odds ratio (OR) 6.07, 95 % confidence interval (CI): 1.77-20.76, P=0.007], while in-hospital mortality occurred in two patients (1.8 %), one in each group. Median OS was 13 months in the HITOC group vs. 27 months in the non-HITOC group (P=0.03).

CONCLUSIONS

In this retrospective single-center cohort, adjunctive HITOC was associated with significantly longer operative time, higher postoperative morbidity, and inferior OS compared with cytoreduction alone. Given the small HITOC sample size and potential residual confounding, these findings should be interpreted cautiously but raise concerns regarding the routine use of HITOC outside clinical trials and highlight the need for prospective comparative evaluation.