1. Relationships between highly recurrent tumor suppressor alterations in 489 leiomyosarcomas.
- Author
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Schaefer IM, Lundberg MZ, Demicco EG, Przybyl J, Matusiak M, Chibon F, Ingram DR, Hornick JL, Wang WL, Bauer S, Baker LH, Lazar AJ, van de Rijn M, Mariño-Enríquez A, and Fletcher JA
- Subjects
- Female, Genes, p16, Humans, Immunohistochemistry, In Situ Hybridization, Fluorescence, PTEN Phosphohydrolase genetics, Receptors, Estrogen genetics, Receptors, Estrogen metabolism, Genes, p53, Leiomyosarcoma genetics, Leiomyosarcoma pathology, Retinoblastoma Binding Proteins genetics, Ubiquitin-Protein Ligases genetics, Uterine Neoplasms genetics, Uterine Neoplasms pathology
- Abstract
Background: Leiomyosarcoma (LMS) is the most common soft tissue and uterine sarcoma, but no standard therapy is available for recurrent or metastatic LMS. TP53, p16/RB1, and PI3K/mTOR pathway dysregulations are recurrent events, and some LMS express estrogen receptor (ER) and/or progesterone receptor (PR). To characterize relationships between these pathway perturbations, the authors evaluated protein expression in soft tissue and uterine nonprimary leiomyosarcoma (np-LMS), including local recurrences and distant metastases., Methods: TP53, RB1, p16, and PTEN expression aberrations were determined by immunohistochemistry (IHC) in tissue microarrays (TMAs) from 227 np-LMS and a comparison group of 262 primary leiomyosarcomas (p-LMS). Thirty-five of the np-LMS had a matched p-LMS specimen in the TMAs. Correlative studies included differentiation scoring, ER and PR IHC, and CDKN2A/p16 fluorescence in situ hybridization., Results: Dysregulation of TP53, p16/RB1, and PTEN was demonstrated in 90%, 95%, and 41% of np-LMS, respectively. PTEN inactivation was more common in soft tissue np-LMS than uterine np-LMS (55% vs 31%; P = .0005). Moderate-strong ER expression was more common in uterine np-LMS than soft tissue np-LMS (50% vs 7%; P < .0001). Co-inactivation of TP53 and RB1 was found in 81% of np-LMS and was common in both soft tissue and uterine np-LMS (90% and 74%, respectively). RB1, p16, and PTEN aberrations were nearly always conserved in p-LMS and np-LMS from the same patients., Conclusions: These studies show that nearly all np-LMS have TP53 and/or RB1 aberrations. Therefore, therapies targeting cell cycle and DNA damage checkpoint vulnerabilities should be prioritized for evaluations in LMS., (© 2021 American Cancer Society.)
- Published
- 2021
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