A Complete Response to Pembrolizumab in Malignant Peritoneal Mesothelioma: A Case Report

Our plain-English summary of A Complete Response to Pembrolizumab in Malignant Peritoneal Mesothelioma: A Case Report, by M. Bairos Menezes, R. Pedroso de Lima, I. Dunões, et al (Curēus, 2024).

The study

• Authors: M. Bairos Menezes, R. Pedroso de Lima, I. Dunões, M. Inácio, R. Dinis
• Journal: Curēus
• Published: 2024;16(1):e52716
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant peritoneal mesothelioma (MPeM) is a rare cancer of the peritoneum with a poor prognosis and nonspecific clinical course. We discuss a case of MPeM in a 59-year-old male who presented with abdominal pain and distension, without any known previous asbestos exposure. The diagnosis was made after a second biopsy finally confirmed epithelioid MPeM in an advanced stage with pleural effusion. The patient underwent six cycles of chemotherapy with cisplatin and pemetrexed, experienced disease progression, and was then started on pembrolizumab as a second-line treatment. The patient achieved a complete response after two years of treatment with pembrolizumab and has been disease-free for almost four years with an Eastern Cooperative Oncology Group (ECOG) performance status of 0. Despite the lack of evidence to support the treatment with immunotherapy for MPeM, our case report encourages its use, highlighting its ability to enable a complete response with pembrolizumab with an excellent quality of life.

Copyright © 2024, Bairos Menezes et al.

In plain English

This case report described one patient, treated at the authors' hospital in Évora, Portugal. He was a 59-year-old male truck driver who in September 2018 had abdominal pain and swelling. He had no known previous exposure to asbestos. A first peritoneal biopsy showed mesothelial hyperplasia but did not rule out low-grade mesothelioma. A later biopsy of a lump in his left flank confirmed epithelioid malignant peritoneal mesothelioma, and a chest scan showed fluid around the right lung (right pleural effusion). After six cycles of cisplatin and pemetrexed chemotherapy, scans showed a new lesion, indicating that the disease had progressed. From January 2020 he received pembrolizumab, an immunotherapy drug, given off-label. The disease was stable at four months and showed a partial response at one year. Scans in 2021 indicated a complete response after 18 months of treatment, and the response was maintained on 2022 and 2023 scans. The only immunotherapy side effect reported was grade 1 hypothyroidism. The authors concluded that pembrolizumab is a reasonable second-line option for this disease, but that more clinical trials are needed to verify these results.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (single patient)
• Who was studied: One 59-year-old male truck driver, a never-smoker, who presented in September 2018 with abdominal pain and distension; the authors are at Hospital Espírito Santo de Évora, Portugal
• Exposure: No known previous asbestos exposure. The report concerns treatment: cisplatin and pemetrexed chemotherapy, then pembrolizumab immunotherapy
• Main results:
  • A first laparoscopic peritoneal biopsy showed mesothelial hyperplasia without excluding low-grade mesothelioma; a second biopsy of the palpable left flank mass confirmed epithelioid malignant peritoneal mesothelioma
  • After six cycles of cisplatin (75 mg/m2) and pemetrexed (500 mg/m2), a new lesion appeared in the right rectus abdominis muscle, indicating disease progression
  • Pembrolizumab 200 mg every three weeks was started in January 2020; the MRI after four months showed stable disease
  • Immunotherapy was well tolerated; the only side effect reported was grade 1 hypothyroidism
  • MRI and PET-CT scans in 2021 indicated a complete response after 18 months of pembrolizumab
  • The complete response was maintained on 2022 and 2023 scans; by November 2023 the patient had been asymptomatic for the last two years with an ECOG performance status of 0
• The authors' conclusion: The authors concluded that pembrolizumab is a reasonable second-line treatment option for malignant peritoneal mesothelioma, though more clinical trials are needed to verify these results
• Limitations the authors state:
  • The authors note a lack of evidence supporting immunotherapy for this disease and that clinical trials are needed to verify their result

Topics

Medical terms in this study, explained in our Lexicon: Pembrolizumab (Keytruda), Peritoneal Mesothelioma, Peritoneum, Prognosis, Asbestos Exposure, Biopsy, Epithelioid, Pleural Effusion.

Related studies

• Complete pathological response to neoadjuvant pemetrexed/cisplatin in combination with regional hyperthermia in a patient with sarcomatoid peritoneal mesothelioma — S. Kruger, M.K. Angele, et al. (2014)
• Complete pathological response after ceritinib for anaplastic lymphoma kinase-rearranged epithelioid peritoneal mesothelioma — S. Sakata, H. Rees, et al. (2021)
• Volumetric PET Response Assessment Outperforms Conventional Criteria in Patients Receiving High-Dose Pembrolizumab for Malignant Mesothelioma — J. Ferdinandus, F. Barbato, et al. (2021)
• Chemotherapy induced pathologic complete response in malignant pleural mesothelioma: a review and case report — C. Bech, J.B. Sørensen (2010)
• Pathological complete response in malignant pleural mesothelioma patients following induction chemotherapy: Predictive factors and outcomes — B. Lau, S. Kumar, et al. (2017)
• A pathological complete response in malignant pleural mesothelioma after combination chemotherapy with Carboplatin and pemetrexed — S.C. Kao, B. McCaughan, et al. (2010)

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