{"entity":{"id":"leiomyosarcoma","kind":"cancer","name":"Leiomyosarcoma","aka":["LMS","Uterine leiomyosarcoma","Smooth muscle sarcoma"],"tldr":"Leiomyosarcoma is a cancer of smooth muscle, most often in the womb, the abdomen behind the bowel or the wall of a large vein. Surgery is the only cure; for spread disease, doxorubicin-based chemotherapy, trabectedin and gemcitabine-docetaxel are the standards, with no targeted drug yet.","summary":"Leiomyosarcoma arises from smooth muscle and is genomically complex, with TP53, RB1 and ATRX loss and no recurrent fusion. Uterine leiomyosarcoma is usually found unexpectedly after surgery for presumed fibroids, which is why morcellation of unsuspected tumours is avoided; retroperitoneal and vascular tumours present late. Complete surgical resection, with radiotherapy for limb tumours, is the only curative treatment and adjuvant chemotherapy has not proven benefit. Metastatic disease is treated with doxorubicin, alone or with trabectedin (LMS-04) or dacarbazine, gemcitabine-docetaxel, trabectedin and pazopanib; responses are modest and median survival is about two years. Immunotherapy has little activity, and trials target the disease's DNA repair and cell-cycle vulnerabilities.","asOf":"2026-09-17","wikipedia":"https://en.wikipedia.org/wiki/Leiomyosarcoma","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Leiomyosarcoma"}],"tags":["subtype-page"],"related":[],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"group":"sarcoma","burden":"One of the two commonest soft-tissue sarcomas in adults, arising in the uterus, the retroperitoneum, large veins and limbs; about half of patients with deep tumours eventually develop metastases, most often to the lungs.","subtypes":["Uterine leiomyosarcoma","Retroperitoneal and intra-abdominal leiomyosarcoma","Vascular leiomyosarcoma (inferior vena cava, large veins)","Limb and cutaneous leiomyosarcoma (better outlook)"],"biomarkers":["TP53, RB1 and ATRX alterations","Grade (FNCLCC) and size","Smooth muscle markers (desmin, h-caldesmon, SMA)","Oestrogen and progesterone receptor in uterine tumours (hormone therapy in low-grade disease)"],"standardOfCare":[{"setting":"Localised","approach":"Wide surgical resection; radiotherapy for limb and trunk tumours; no morcellation of uterine masses that could be sarcoma; adjuvant chemotherapy not standard.","refs":["imrt-igrt"]},{"setting":"Metastatic, first line","approach":"Doxorubicin plus trabectedin (LMS-04) or doxorubicin alone; gemcitabine-docetaxel as an alternative, especially in uterine disease.","refs":["doxorubicin","trabectedin","gemcitabine","docetaxel"]},{"setting":"Later lines","approach":"Trabectedin, pazopanib, dacarbazine-based regimens, aromatase inhibitors in hormone receptor-positive low-grade uterine disease; metastasectomy for limited lung spread.","refs":["trabectedin","pazopanib","letrozole"]}],"stateOfArt":["LMS-04 gave the first randomised progression-free survival gain in a decade by combining doxorubicin with trabectedin.","Lung metastasectomy in selected patients produces long survival that chemotherapy alone does not.","Genomic profiling has defined the disease but not yet yielded a targeted drug."],"history":[{"year":1994,"title":"Doxorubicin-ifosfamide becomes the reference first-line regimen for soft-tissue sarcoma","refs":["doxorubicin","ifosfamide"]},{"year":2007,"title":"Trabectedin approved in Europe for soft-tissue sarcoma","refs":["trabectedin"]},{"year":2014,"title":"Morcellation warnings after unsuspected uterine leiomyosarcoma spread","refs":[]},{"year":2022,"title":"LMS-04: doxorubicin plus trabectedin improves progression-free survival","refs":["trabectedin"]}],"pipeline":["trabectedin"],"openProblems":["No targeted or immune therapy works in most patients.","Uterine tumours are still discovered by accident after fibroid surgery.","Adjuvant chemotherapy remains unproven."],"parent":"sarcoma"},"route":"/cancers/leiomyosarcoma/","neighbours":{"drug":[{"id":"docetaxel","kind":"drug","name":"Docetaxel","route":"/drugs/docetaxel/"},{"id":"doxorubicin","kind":"drug","name":"Doxorubicin","route":"/drugs/doxorubicin/"},{"id":"gemcitabine","kind":"drug","name":"Gemcitabine","route":"/drugs/gemcitabine/"},{"id":"ifosfamide","kind":"drug","name":"Ifosfamide","route":"/drugs/ifosfamide/"},{"id":"letrozole","kind":"drug","name":"Letrozole (and other aromatase inhibitors)","route":"/drugs/letrozole/"},{"id":"pazopanib","kind":"drug","name":"Pazopanib","route":"/drugs/pazopanib/"},{"id":"trabectedin","kind":"drug","name":"Trabectedin","route":"/drugs/trabectedin/"}],"technology":[{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"}],"cancer":[{"id":"sarcoma","kind":"cancer","name":"Sarcomas (soft tissue, bone, GIST)","route":"/cancers/sarcoma/"}]}}