A Case Report of Mesothelioma Response to Endocrine Therapy in Synchronous Breast Cancer and Pleural Epithelioid Mesothelioma: A Double Exemestane Effect

Our plain-English summary of A Case Report of Mesothelioma Response to Endocrine Therapy in Synchronous Breast Cancer and Pleural Epithelioid Mesothelioma: A Double Exemestane Effect, by M. Pina, R. Fernandes, D. Fonseca, et al (Curēus, 2022).

The study

• Authors: M. Pina, R. Fernandes, D. Fonseca, C. Oliveira, A. Rodrigues
• Journal: Curēus
• Published: 2022;14(11):e31579
• Type of article: Case report
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Synchronous pleural mesothelioma (PM) and breast cancer are extremely rare. We present the case of a 53-year-old female diagnosed with localized breast cancer. She was radically treated with surgery, but during the adjuvant radiotherapy, the patient developed fever and dyspnoea, and pleural thickening was found on a CT scan. The biopsy confirmed the diagnosis of a synchronous malignancy - pleural epithelioid mesothelioma. The patient stopped radiotherapy and started adjuvant endocrine therapy with exemestane, a third-generation aromatase inhibitor, with an unexpected partial response to the PM. The patient remains on exemestane with a sustained partial response. This is a rare case of synchronous tumours that show a real-life benefit of exemestane in the treatment of pleural mesothelioma, which was only described in vitro, with a good sustained response. This suggests a potential for exemestane in the treatment of mesothelioma, which is an aggressive form of cancer with few therapeutics with sustained results.

Copyright © 2022, Pina et al.

In plain English

This was a case report about one patient from a cancer hospital in Porto, Portugal. A 53-year-old woman, a non-smoker without known asbestos exposure, had a suspicious breast lesion found on screening in November 2020. After a partial left mastectomy in March 2021, tissue testing confirmed stage IA invasive ductal breast cancer. She started exemestane 25 mg a day, an endocrine (hormone) therapy, in April 2021 and radiotherapy in May 2021. On the sixth day of radiotherapy she developed fever and malaise. A CT scan showed left pleural thickening (the lining around the lung) with implants up to 53 mm by 25 mm. A later PET-CT showed these findings shrinking compared with the CT 30 days earlier. A biopsy found malignant epithelioid mesothelioma. Radiotherapy was stopped after seven days, but exemestane continued. In July 2022 she had no symptoms and was still on exemestane. A CT scan dated June 2022 in its figure caption showed a sustained partial response. The authors concluded that the case showed an effect of exemestane on pleural mesothelioma in a patient, supporting earlier preclinical studies.

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 53-year-old woman with breast cancer and pleural epithelioid mesothelioma, reported by authors at the Instituto Português de Oncologia do Porto, Portugal. She was followed from a screening finding in November 2020 to July 2022.
• Exposure: No known asbestos exposure. The patient was a non-smoker. The treatment of interest was exemestane, a third-generation aromatase inhibitor, given for her breast cancer.
• Main results:
  • Screening found a suspicious breast lesion in November 2020. After surgery in March 2021, histology confirmed ductal invasive carcinoma, luminal A, stage IA (pT1bN0sn cM0).
  • Exemestane 25 mg/day was started in April 2021 as adjuvant endocrine therapy for the breast cancer.
  • A CT scan in May 2021, during radiotherapy, showed a small left pleural effusion and pleural thickening with multiple implants, the largest 53 mm by 25 mm.
  • A PET-CT showed the pleural findings decreasing in size compared with the CT scan done 30 days earlier.
  • The pleural biopsy was compatible with malignant epithelioid mesothelioma.
  • Radiotherapy was suspended after seven days of treatment. Exemestane was continued.
  • The thoracic tumour team judged the mesothelioma not suitable for local resection or chemoradiation. Because a partial response was assumed in relation to the exemestane, she continued it with close follow-up.
  • In July 2022 the patient was clinically asymptomatic and still on exemestane with very good tolerance. The text says the CT scan showed a sustained partial response.
  • The figure caption dates the follow-up CT scan to June 2022. It describes a significant reduction of pleural thickness and an 11 mm enlarged lymph node.
  • At the time of the report the patient had been on exemestane for 14 months with good response, tolerance and quality of life.
• The authors' conclusion: The authors concluded that treating this patient's breast cancer first let them observe an effect of exemestane on pleural mesothelioma in a living patient. They said this supports previously published preclinical data and may offer a better-tolerated treatment option than chemotherapy.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Epithelioid, Pleural Mesothelioma, Pleural Thickening, CT Scan, Biopsy.

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