mTOR inhibitors show similar efficacy to chemo in advanced perivascular epithelioid cell tumors

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Mammalian target of rapamycin (mTOR) inhibitors have shown similar efficacy to chemotherapy in treating advanced perivascular epithelioid cell tumors (PEComas), a rare group of sarcomas. This suggests that mTOR inhibitors should be preferred whenever possible, considering the associated morbidity linked with chemotherapy.

In addition, the study identified TFE3 overexpression as a biomarker that correlates with a more aggressive disease course and worse prognosis in PEComas. These findings provide valuable insights into treatment options and prognostic indicators for patients with advanced PEComas, aiding clinicians in making informed decisions about therapeutic approaches and patient management.

The study included a total of 29 patients, with the majority presenting with malignant PEComa (n = 17). The median overall survival was found to be 204.9 months, while the median progression-free survival was 92.4 months from the first-line treatment and 15.8 months when considering all lines of treatment combined.

One notable finding was the correlation between TFE3 overexpression and a higher risk of death. Patients with TFE3 overexpression exhibited a shorter median overall survival (P = 0.001) and an increased hazard ratio for mortality (HR: 11.8, P = 0.04). These results suggest that TFE3 overexpression could serve as a valuable biomarker for identifying a subgroup of PEComas with a worse prognosis and more aggressive behavior.

The study found that chemotherapy and mTOR inhibitors demonstrated similar overall survival (P = 0.84) and first-line progression-free survival (P = 0.67) and the combined progression-free survival was similar across various treatments, including individual mTOR inhibitors, chemotherapy, immune checkpoint inhibitors, and others (P = 0.19).

Testa S, Bui NQ, Ganjoo KN. Systemic Treatments and Molecular Biomarkers for Perivascular Epithelioid Cell Tumors: A Single-institution Retrospective Analysis. Cancer Res Commun. 2023;3(7):1212-1223. doi: 10.1158/2767-9764.CRC-23-0139. PMID: 37448552; PMCID: PMC10335919.