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9 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
PEComa is a rare tumour, grouped with the sarcomas, of cells that sit around blood vessels and share features of muscle and pigment cells. Most are benign, but malignant ones spread and resist chemotherapy. They usually have lost the TSC1 or TSC2 brake on the growth signal mTOR, and in 2021 the mTOR blocker nab-sirolimus became the first approved treatment.
Perivascular epithelioid cell tumours express both smooth muscle and melanocytic markers (HMB-45, Melan-A) and include renal angiomyolipoma, pulmonary lymphangioleiomyomatosis and clear cell sugar tumour of the lung as well as PEComa not otherwise specified of the uterus, retroperitoneum, gastrointestinal tract and soft tissue. Most carry biallelic loss of TSC1 or TSC2, with or without tuberous sclerosis complex, which unleashes mTOR signalling; a minority instead carry TFE3 fusions and do not respond to mTOR inhibition. Malignancy is predicted by size over five centimetres, infiltrative growth, high grade, necrosis, mitotic count and vascular invasion.
Complete surgical resection is the treatment for localised tumours, with no established role for adjuvant therapy, and surveillance for those with high-risk features. Conventional chemotherapy has little activity in malignant PEComa. Case series of sirolimus, everolimus and temsirolimus showed responses in TSC-altered tumours, establishing mTOR inhibition as the rational systemic therapy.
| Setting | Approach | Guideline |
|---|---|---|
| Localised | Complete resection; surveillance for tumours with malignant features; no proven adjuvant therapy. | not mapped |
| Advanced malignant PEComa | Nab-sirolimus (AMPECT; FDA approved 2021); oral sirolimus, everolimus or temsirolimus as alternatives; check TSC status. | not mapped |
| After mTOR inhibitor | Anthracycline- or gemcitabine-based chemotherapy has modest activity; trials of mTOR-based combinations; PRECISION 1 for TSC-altered tumours. | not mapped |