Divided by an ocean of water but united in an ocean of uncertainty: a transatlantic review of mesothelioma surgery guidelines

Perioperative discordance in mesothelioma cell type after pleurectomy/decortication-a possible detrimental effect of neoadjuvant chemotherapy due to epithelial to mesenchymal transition?

OBJECTIVES

The goal was to evaluate the accuracy of preoperative histological assessment and the factors affecting the accuracy and the subsequent effect on postoperative survival after surgical treatment for malignant pleural mesothelioma (MPM).

METHODS

We analysed the perioperative course of patients who underwent surgery for MPM in a single institution over a 5-year period. The primary end point was to evaluate the proportion of histological discordance between preoperative assessment and postoperative histological diagnosis. The secondary end point was to evaluate its prognostic effect on postoperative survival after surgical treatment.

RESULTS

One-hundred and twenty-nine patients were included in this study. Histological discordance between preoperative assessment and postoperative histological diagnosis was found in 27 of 129 patients (20.9%): epithelial to biphasic/sarcomatoid (negative discordance) in 24 and biphasic to epithelial (positive discordance) in 3 (P-value < 0.001). All 24 patients who exhibited epithelial-to-mesenchymal transition (EMT) had received neoadjuvant chemotherapy (P-value: 0.006). In the 34 patients who underwent upfront surgery, only 1 case (2.9%) of EMT was identified (P-value: 0.127). EMT was not associated with a less invasive method of biopsy (P-value: 0.058) or with the volume or maximum diameter of the biopsy (P-value: 0.358 and 0.518, respectively), but it was significantly associated with the receipt of neoadjuvant chemotherapy (P-value: 0.006). At a median follow-up of 17 months (IQR: 11.0-28.0), 50 (39%) patients are still alive. Overall survival was significantly reduced in those patients who received neoadjuvant chemotherapy and who exhibited discordance (EMT) compared to those who did not: 11 (95% CI: 6.2-15.8) months versus 19 (95% CI: 14.2-23.8) months (P-value < 0.001). In addition, there was no difference in overall survival between those who received neoadjuvant chemotherapy and those who had upfront surgery: 16 (95% CI: 2.5-19.5) months versus 30 (95% CI: 11.6-48.4) months (P-value: 0.203).

CONCLUSIONS

The association of neoadjuvant chemotherapy with perioperative histological discordance can be explained by EMT, which leads to worse survival. Therefore, there is an argument for the preferential use of upfront surgery in the treatment of otherwise resectable MPM.

Induction Chemotherapy Followed by Pleurectomy Decortication and Hyperthermic Intraoperative Chemotherapy (HITHOC) for Early-Stage Epitheliod Malignant Pleural Mesothelioma-A Prospective Report

Malignant pleural mesothelioma (MPM) is an aggressive disease with poor prognosis and the current treatment for early-stage MPM is based on a multimodality therapy regimen involving platinum-based chemotherapy preceding or following surgery. To enhance the cytoreductive role of surgery, some peri- or intra-operative intracavitary treatments have been developed, such as hyperthermic chemotherapy, but long-term results are weak. The aim of this study was to report the post-operative results and mid-term outcomes of our multimodal intention-to-treat pathway, including induction chemotherapy, followed by surgery and Hyperthermic Intraoperative THOracic Chemotherapy (HITHOC) in the treatment of early-stage epithelioid MPM. Since 2017, stage I or II epithelioid MPM patients have been inserted in a surgery-based multimodal approach comprising platinum-based induction chemotherapy, followed by pleurectomy and decortication (P/D) and HITHOC with cisplatin. The Kaplan–Meier method was used to estimate overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS). During the study period, n = 65 patients affected by MPM were evaluated by our institutional Multidisciplinary Tumour Board; n = 12 patients with stage I-II who had no progression after induction chemotherapy underwent P/D and HITHOC. Post-operative mortality was 0, and complications developed in n = 7 (58.3%) patients. The median estimated OS was 31 months with a 1-year and 3-year OS of 100% and 55%, respectively. The median PFS was 26 months with 92% of a 1-year PFS, whereas DFS was 19 months with a 1-year DFS rate of 83%. The multimodal treatment of early-stage epithelioid MPM, including induction chemotherapy followed by P/D and HITHOC, was well tolerated and feasible with promising mid-term oncological results.

Multi-institutional survey of malignant pleural mesothelioma patients in the Hokushin region

BACKGROUND

Malignant pleural mesothelioma (MPM) is a major occupational and environmental neoplasm. The purpose of this study was to validate the clinical and epidemiological factors, diagnosis, and initial treatment among MPM patients in the Hokushin region.

METHODS

We surveyed retrospective data from 152,921 cancer patients in 22 principal hospitals.

RESULTS

A total of 166 MPM cases were newly diagnosed. These patients consisted of 136 men and 30 women, with a median age of 69 years. We estimated the incidence rate for MPM to be 0.55 cases per 100,000 person-years in this study. The ratio per 100,000 population-years was 0.39 in Fukui, 0.60 in Ishikawa, 1.02 in Toyama and 0.35 in Nagano. Forty-five patients were discovered when diagnosed incidentally in patients under observations for other diseases. Forty-six cases were diagnosed as localized disease, while 13 had accompanying regional lymph node metastasis. Furthermore, 44 cases showed infiltration into adjacent organs. A histo-cytological diagnosis was made in 164 cases (98.8%). A surgical approach, chemotherapy, and radiotherapy were performed for 33, 88, and 6 patients, respectively, while 44 patients (26.5%) received best supportive care. Multimodality therapy was conducted in just 3.0% of the MPM patients CONCLUSION: MPM has a tragically rapid progression if discovered under observations for other diseases. Workers in health-related fields should be on high alert for aggressive MPM. Better evaluation and multi-disciplinary approaches to MPM in these regions are needed to optimize multimodality therapy.