Evaluation of prognostic histological parameters proposed for pleural mesothelioma in diffuse malignant peritoneal mesothelioma. A short report

Abstract

Introduction Diffuse malignant peritoneal mesothelioma (DMPM) is a rare malignant neoplasm with poor survival that shares some similarities with the best-known pleural variant, pleural mesothelioma. The recent European Reference Network on Rare Adult Cancers (EURACAN)/International Association for the Study of Lung Cancer (IASLC) proposals attempted to improve the histological diagnosis and patient risk stratification. Herein, we investigated whether the pathology recommendations and suggestions of the pleural proposals were applicable to diffuse malignant peritoneal mesothelioma. Methods Fifty multiple laparoscopic biopsies of DMPM were consecutively collected at the Pathology Unit of the University of Bari. A two-tier system, i.e., low, and high grade, was used to categorize 34 epithelioid DMPMs. Architectural patterns, cytological features and stromal changes were also reported. Immunohistochemistry was performed for BRCA1-associated protein 1 (BAP1), programmed death-ligand 1 (PD-L1), and Ki67, while fluorescence in situ hybridization (FISH) was performed for p16/cyclin-dependent kinase inhibitor 2A (CDKN2A). Results High-grade epithelioid mesothelioma, high Ki67, and p16/CDKN2A deletion were significantly associated with short survival (p = 0.004, p < 0.0001, and p = 0.002, respectively). BAP1 loss and PD-L1 negativity were the most common findings. Multivariate analysis revealed that the nuclear grading system and p16 deletion significantly correlated with survival (p = 0.003 each). Conclusions The present study examined the prognostic significance of several factors proposed for pleural mesothelioma in an extra pleural site. Notably, the introduction of a grading system may provide better risk stratification in epithelioid DMPM. Ki67, BAP1 and p16/CDKN2A should also be measured whenever possible. A detailed report with all supportive data would allow us to collect sufficient information for use in further studies on larger case series.

Genomic and transcriptomic analysis of a diffuse pleural mesothelioma patient-derived xenograft library

“…The predominant architectural pattern in the 15 DPM epithelioid histology tumors included the following: S ( n = 7, 47%), T ( n = 4, 26.4%), and TP ( n = 4, 26.5%) (Table 2 ). Unfavorable architectural patterns and/or cytologic features [ 3 , 29 , 36 ] were seen in the majority of epithelioid DPM (80%; n = 12) with S pattern in 12 and MP pattern and P features present in 2 and 1 tumors, respectively. S pattern was seen in all 11 paired PDX samples and was predominant in 9 (82%).…”

“…Concordant predominant architectural patterns were observed in 64% (7/11) of paired patient and PDX samples. In the four cases with discrepant predominant patterns, the predominant pattern noted in the patient tissue was a favorable pattern (i.e., T ( n = 2) and TP ( n = 2)), while the predominant pattern in the corresponding PDX samples were S (i.e., unfavorable) [ 3 , 36 ]. The predominant pattern noted in these 4 patient samples were present as a non-dominant histology in MSK_LX413 but not in MSK_LX333, MSK_LX944B, and MSK_LX96 which may be attributable to tumor heterogeneity of the sampled material.…”

Metachronous double primary malignant tumors with nasopharyngeal carcinoma and diffuse malignant peritoneal mesothelioma accompanied with paraneoplastic syndromes treated with nivolumab: A case report

“…The pathological subtypes of MPM were classified as epithelioid, biphasic and sarcomatoid subtypes, the epithelial type has the highest incidence, accounting for 50%, with the best prognosis. [9] However, the median survival of inoperable ones is short, only about 10 to 13 months. [10,11] The PFS in first line is 12 months, OS is 23 months in our case, much longer than the reports.…”

Prognostic factors of malignant peritoneal mesothelioma: a retrospective study of 52 female patients

“…Then, 3 high-power fields were randomly selected in each section, and the average proportion of positive cells was obtained: < 5%, negative; 5–25%, “+”; 26–50%, ++; >50%, “+++.” Ki67 ≤ 10% and > 10% were considered to be low and high, respectively. According to reports by Pezzuto F et al [ 19 , 20 ], Pillai K et al [ 21 ], and Kusamura S et al [ 22 ], and the Chinese Expert Consensus on the Diagnosis and Treatment of Diffuse Malignant Peritoneal Mesothelioma , Ki67 >9% is a relative contraindication for cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC). Therefore, Ki67=10% was considered the cutoff value in this study.…”