An Investigation of Cancer-Directed Surgery for Different Histologic Subtypes of Malignant Pleural Mesothelioma

Abstract

The role of cancer-directed surgery in the treatment of stage I-IIIA malignant pleural mesothelioma (MPM) by histologic subtypes remains controversial. The objective of this study was to evaluate the survival of the different histologic subtypes for stage I-IIIA MPM stratified by cancer-directed surgery and nonoperative management. How is the histologic subtype of MPM, clinical stage of MPM, and use of cancer-directed surgery for MPM associated with overall survival? Overall survival of patients with stage I-IIIA epithelioid, sarcomatoid, and biphasic MPM in the National Cancer Database from 2004 through 2017 who underwent cancer-directed surgery (ie, surgery with or without chemotherapy or radiation) or chemotherapy with or without radiation (nonoperative management) was evaluated using Kaplan-Meier analysis, multivariate Cox proportional hazards analysis, and propensity score-matched analysis. Of 2,285 patients with stage I-IIIA MPM who met inclusion criteria, histologic subtype was epithelioid in 71%of patients, sarcomatoid in 12%of patients, and biphasic in 17%of patients. Median survival was 20months in the epithelioid group, 8months in the sarcomatoid group, and 13months in the biphasic group (P< .01). Among patients who underwent surgery, median survival was 25months in the epithelioid group, 8months in the sarcomatoid group, and 15months in the biphasic group (P< .01). In multivariate Cox proportional hazards analyses, surgery was associated with improved survival in the epithelioid group (P< .01) but not in the sarcomatoid (P= .63) or biphasic (P= .21) groups. These findings were consistent in propensity score-matched analyses for each MPM histologic type. In this national analysis, cancer-directed surgery was found to be associated with improved survival for stage I-IIIA epithelioid MPM, but not for biphasic or sarcomatoid MPM.