ABSTRACT
BACKGROUND: Uterine leiomyosarcoma (ULMS) is an aggressive, rapidly progressive tumor lacking clinical and molecular predictors of outcome. METHODS: ULMS patients (n = 349) were classified by disease status at presentation to MDACC as having intra-abdominal (n = 157) or distant metastatic disease (n = 192). Patient, tumor, treatment, and outcome variables were retrospectively retrieved. Formalin-fixed, paraffin-embedded tumor and control tissues from these patients (n = 109) were assembled in a tissue microarray and evaluated for hormone receptors and markers of angiogenesis, cell-cycle progression and survival. Patient, tumor, and treatment variables were correlatively analyzed. RESULTS: The 5- and 10-year disease-specific survival (DSS) for the cohort was 42 and 27 %, respectively. Patients with primary intra-abdominal tumors had better outcomes than those with recurrent intraperitoneal tumors. Whites had a more favorable prognosis. In patients with intra-abdominal tumors, only mitotic count >10M/10HPF portended poorer prognosis. Patients with pulmonary metastasis had improved outcomes with "curative" metastasectomy. ULMS samples exhibited loss of ER and PR expression, overexpressed Ki-67, and altered p53, Rb, p16, cytoplasmic ß-catenin, EGFR, PDGFR-α, PDGFR-ß, and AXL levels. Metastatic tumors had increased VEGF, Ki-67, and survivin expression versus localized disease. Survivin and ß-catenin expression were associated with intraperitoneal recurrence; high bcl-2 expression predicted longer DSS. CONCLUSIONS: Analysis of both clinicopathologic factors and immunohistochemical biomarkers in ULMS identified several prognostic clinical and molecular factors, suggesting that further study may lead to improved ULMS understanding and treatment.
Subject(s)
Biomarkers, Tumor/metabolism , Leiomyosarcoma/metabolism , Leiomyosarcoma/secondary , Neoplasm Recurrence, Local/metabolism , Uterine Neoplasms/metabolism , Uterine Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Disease-Free Survival , Female , Humans , Inhibitor of Apoptosis Proteins/metabolism , Ki-67 Antigen/metabolism , Middle Aged , Mitotic Index , Prognosis , Proportional Hazards Models , Receptor Protein-Tyrosine Kinases/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Retinoblastoma Protein/metabolism , Survival Rate , Survivin , Tissue Array Analysis , Tumor Suppressor Protein p53/metabolism , Young Adult , beta Catenin/metabolismABSTRACT
PURPOSE: The significance of mTOR activation in uterine leiomyosarcoma (ULMS) and its potential as a therapeutic target were investigated. Furthermore, given that effective therapies likely require combination mTOR blockade with inhibition of other targets, coupled with recent observations suggesting that Aurora-A kinase (Aurk-A) deregulations commonly occur in ULMS, the preclinical impact of dually targeting both pathways was evaluated. EXPERIMENTAL DESIGN: Immunohistochemical staining was used to evaluate expression of activated mTOR components in a large (>200 samples) ULMS tissue microarray. Effects of mTOR blockade (using rapamycin) and Aurk-A inhibition (using MLN8237) alone and in combination on human ULMS cell growth, cell-cycle progression, and apoptosis were assessed in cellular assays. Drug interactions were determined via combination index analyses. The antitumor effects of inhibitors alone or in combination were evaluated in vivo. RESULTS: Enhanced mTOR activation was seen in human ULMS samples. Increased pS6RP and p4EBP1 expression correlated with disease progression; p4EBP1 was found to be an independent prognosticator of patient outcome. Rapamycin inhibited growth and cell-cycle progression of ULMS cell strains/lines in culture. However, only a cytostatic effect on tumor growth was found in vivo. Combining rapamycin with MLN8237 profoundly (and synergistically) abrogated ULMS cells' growth in culture; interestingly, these effects were seen only when MLN8237 was preadministered. This novel therapeutic combination and scheduling regimen resulted in marked tumor growth inhibition in vivo. CONCLUSIONS: mTOR and Aurk-A pathways are commonly deregulated in ULMS. Preclinical data support further exploration of dual mTOR and Aurk-A therapeutic blockade for human ULMS.