Therapeutic surgery for nonepithelioid malignant pleural mesothelioma: is it really worthwhile?

Debate remains about the relative prognostic importance of the histologic subtype of malignant pleural mesothelioma.

From a prospective database, the details of 312 malignant pleural mesothelioma surgical patients were reviewed. A comparison was made of the survival from the three major cell types.

One hundred ninety-five patients underwent radical surgery, and 117 underwent nonradical surgery. Final histologic subtype was epithelioid in 218 patients, biphasic in 66 patients, and sarcomatoid in 28 patients. The median survival was 15.3 months in the epithelioid group, 10.1 months in the biphasic group, and 5.0 months in the sarcomatoid group. On univariate analysis in the epithelioid group, age (p = 0.005), International Mesothelioma Interest Group stage (p = 0.001), radicality of the procedure (p = 0.001), leukocytosis (p = 0.016), and preoperative or postoperative chemotherapy (p = 0.012) were significant prognostic factors influencing postoperative survival. In the biphasic group, preoperative anemia was the only significant factor (p = 0.007). In sarcomatoid patients, International Mesothelioma Interest Group stage and radicality of the surgical procedure were significant prognostic variables (p = 0.012 and p = 0.015, respectively). Multivariate analysis in the epithelioid group identified International Mesothelioma Interest Group stage (p = 0.001), radicality of the procedure (p = 0.008), and preoperative or postoperative chemotherapy (p = 0.007) as significant prognostic factors, whereas in the sarcomatoid group, only the International Mesothelioma Interest Group stage (p = 0.012) was significant and the radicality of surgery had no effect.

The extremely poor prognosis of sarcomatoid malignant pleural mesothelioma is independent of the extent of surgery unlike other cell types. Patients with sarcomatoid histology should therefore be considered separately in trials evaluating radical procedures and adjuvant treatment. The treatment of biphasic pleural mesothelioma remains debatable.