The eighth TNM classification for malignant pleural mesothelioma

Abstract

In 2016, the International Association for the Study of Lung Cancer (IASLC) published a number of revisions of the seventh edition of the tumor, node and metastasis (TNM) classification for malignant pleural mesothelioma (MPM). The purpose was to establish a set of recommendations for the eighth edition of the TNM staging system. A large number of patients were included in the IASLC database and subsequently analysed to determine new definitions for the components of the TNM classification. A number of important changes were introduced for the T component. Survival analysis of the different T categories showed no significant difference in categories T1a and T1b. This has resulted in a collapse of categories T1a and T1b into one category T1. In addition, tumor thickness was also significantly associated with overall survival. The descriptors for the N components have been redefined as well for the eighth TNM classification. A major revision is the removal of category N3 in the N component. Both intrapleural and extrapleural (N1 and N2 in the seventh edition) are now combined into a single category N1. Lymph nodes that were previously categorized as N3 are now considered N2. For the M component, no redefinition has been published. However, a recommendation has been made to only consider M1 involvement as stage IV disease. This is in contrast to the seventh edition in which T4 and N3 disease were considered stage IV as well. In conclusion, a number of important revisions for the eighth TNM classification of MPM have been published as a result of this IASLC project. This type of large-scale and international joint efforts are key in establishing effective staging systems. Research into using tumor thickness as a prognostic instrument will be an important part of any future editions of the TNM classification.

Update on biology and management of mesothelioma

“…Response rates to cisplatin/pemetrexed were 41% in clinical trial settings [5], but 26.3% in a subsequent nonrandomised study of 1704 patients [6]. Where licensed, bevacizumab is added to this regime since cisplatin/pemetrexed/bevacizumab combination was associated with median (95% CI) survival of 19 (16)(17)(18)(19)(20)(21)(22) months, versus 16 (14-18) months with cisplatin/ pemetrexed alone [7], with grade 3-4 adverse events occurring in 71% versus 62%, respectively [7]. A number of patients will not be fit enough to receive first-line chemotherapy, and in addition, of those who do receive chemotherapy, many will risk the associated adverse effects of chemotherapy without any benefit in terms of disease response.…”

Deep Sequencing Analysis Identified a Specific Subset of Mutations Distinctive of Biphasic Malignant Pleural Mesothelioma

“…According to the WHO recommendation, tumors containing at least 10% of each component (epithelioid or sarcomatoid) are classified as having biphasic histology [36]. The 8th TNM classification system was adopted and the surgical-pathological stages (re)assigned accordingly [37]. Detailed diagnostic and therapeutic strategy information regarding this cohort were reported in our previous manuscript [13].…”

Integrating Data from Multidisciplinary Management of Malignant Pleural Mesothelioma: A Cohort Study

“…Finally, seven patients were classi ed as stage IV, indicating that distant metastasis was found (Table 1). Overall, the 76% of patients have an early stage of disease (IA-B, II) according to the TNM-8 Ed system [ 19 ]. As a result, the majority of patients were susceptible to surgical therapy and/or multimodal approach.…”