sirolimus and Abdominal-Neoplasms

Perivascular epithelioid cell tumors (PEComas) include different morphological entities originating from perivascular epithelioid cells. Their clinical behavior is not predictable, and there are no strict histologic criteria for malignancy, although larger tumors with infiltrative growth, hypercellularity, cellular atypia, atypical mitoses, and necrosis generally have a malignant course. Pediatric PEComas are rare, with less than 40 cases reported, mostly in children older than 5 years. We describe a case of malignant PEComa of the ligamentum teres in a 2-year-old girl, characterized by the occurrence of local relapse after primary treatment with chemotherapy and surgery and poor response to imatinib mesilate and temsirolimus used after further analyses confirmed p70S6K expression involved in the mTOR pathway. The girl was eventually treated with a debulking surgical procedure and is now alive with disease 6 years after diagnosis. Literature data of children affected by PEComas were also analyzed, trying to identify pathologic characteristics that could predict their course and therapeutic options. Histologically, they may be differentiated in 3 prognostic categories: (1) benign, lacking unfavorable morphological markers; (2) with uncertain malignant potential, carrying 1 unfavorable marker; and (3) malignant, with at least 2 unfavorable markers. In the literature, 9% of cases occurred as a second malignancy probably because of genomic instability related to treatment. Their different biology and the potential value of targeted therapies remain to be explored. The indolent evolution in our patient was similar to that reported in some other cases in the literature. In terms of treatment, the present case suggests a minor response to temsirolimus compared with the adult population.

Topics: Abdominal Neoplasms; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzamides; Biopsy; Child, Preschool; Combined Modality Therapy; Diagnostic Errors; Etoposide; Female; Humans; Imatinib Mesylate; Intestinal Obstruction; Ligaments; Liver Neoplasms; Neoplasm Recurrence, Local; Peritoneal Neoplasms; Perivascular Epithelioid Cell Neoplasms; Piperazines; Protein Kinase Inhibitors; Pyrimidines; Radiography; Sarcoma, Clear Cell; Sirolimus; X Chromosome Inactivation

Plexiform neurofibromas (PNs) are common and potentially debilitating complications of neurofibromatosis 1 (NF1). These benign nerve-sheath tumors are associated with significant pain and morbidity because they compress vital structures. The mammalian target of rapamycin (mTOR) pathway is a major mediator involved in tumor growth in NF1. We present 3 cases of patients with NF1, aged 8, 16, and 17 years, followed for inoperable and symptomatic PNs; patients received sirolimus for life-threatening and painful neurofibromas after multidisciplinary consultation. Epidemiologic, clinical, and radiologic data were retrospectively collected. The volume of PNs did not differ between baseline and 12-month follow-up and pain was alleviated, with withdrawal of analgesics in 2 cases at 6 months, and significantly decreased for the third case. Sirolimus for inoperable symptomatic PNs in patients with NF1 permitted stabilization of mass and produced unpredictable and important alleviation of pain in all cases with good tolerance. This treatment was proposed in extreme cases, in absence of therapeutic alternatives, after multidisciplinary consensus. The mTOR pathway may be both a major mediator of NF1 tumor growth and regulator of nociceptor sensitivity. mTOR inhibitors clinically used as anticancer and immunosuppressant drugs could be a potential treatment of chronic pain.

Topics: Abdominal Neoplasms; Adolescent; Child; Chronic Pain; Cooperative Behavior; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Follow-Up Studies; Humans; Interdisciplinary Communication; Male; Neurofibroma, Plexiform; Neurofibromatosis 1; Pain Measurement; Sirolimus

Tuberous sclerosis complex (TSC) is a multi-organ disorder caused by mutations of the TSC1 or TSC2 genes. A key function of these genes is to inhibit mTORC1 (mechanistic target of rapamycin complex 1) kinase signaling. Cells deficient for TSC1 or TSC2 have increased mTORC1 signaling and give rise to benign tumors, although, as a rule, true malignancies are rarely seen. In contrast, other disorders with increased mTOR signaling typically have overt malignancies. A better understanding of genetic mechanisms that govern the transformation of benign cells to malignant ones is crucial to understand cancer pathogenesis. We generated a zebrafish model of TSC and cancer progression by placing a heterozygous mutation of the tsc2 gene in a p53 mutant background. Unlike tsc2 heterozygous mutant zebrafish, which never exhibited cancers, compound tsc2;p53 mutants had malignant tumors in multiple organs. Tumorigenesis was enhanced compared with p53 mutant zebrafish. p53 mutants also had increased mTORC1 signaling that was further enhanced in tsc2;p53 compound mutants. We found increased expression of Hif1-α, Hif2-α and Vegf-c in tsc2;p53 compound mutant zebrafish compared with p53 mutant zebrafish. Expression of these proteins probably underlies the increased angiogenesis seen in compound mutant zebrafish compared with p53 mutants and might further drive cancer progression. Treatment of p53 and compound mutant zebrafish with the mTORC1 inhibitor rapamycin caused rapid shrinkage of tumor size and decreased caliber of tumor-associated blood vessels. This is the first report using an animal model to show interactions between tsc2, mTORC1 and p53 during tumorigenesis. These results might explain why individuals with TSC rarely have malignant tumors, but also suggest that cancer arising in individuals without TSC might be influenced by the status of TSC1 and/or TSC2 mutations and be potentially treatable with mTORC1 inhibitors.

Topics: Abdominal Neoplasms; Alleles; Animals; Blood Vessels; Cell Transformation, Neoplastic; Gene Silencing; Heterozygote; Intracellular Signaling Peptides and Proteins; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Multiprotein Complexes; Mutation; Neovascularization, Pathologic; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Up-Regulation; Vascular Endothelial Growth Factor A; Zebrafish; Zebrafish Proteins

Lymphangioleiomyomatosis (LAM) is a rare systemic disease of young women arising from mutations in the tuberous sclerosis complex (TSC) genes, TSC1 or TSC2. This disrupts the mammalian target of rapamycin (mTOR) pathway, affecting cellular proliferation and growth. mTOR inhibitors are a promising novel therapy in LAM. The mTOR inhibitor sirolimus is reported to produce resolution of lymphatic abnormalities in LAM, but the efficiacy of the mTOR inhibitor everolimus has not been assessed. We aimed to examine the efficacy of everolimus on lymphatic abnormalities in LAM.. Open-label treatment of five patients with sporadic LAM (sLAM) and abdominopelvic and lung involvement at the outpatient LAM clinic of a tertiary city teaching hospital. Clinical data were collected during treatment of the women and included regular clinical reviews, everolimus levels, lung function and computed tomography assessment before and after 6 months of everolimus treatment.. Symptoms and level of resolution of lymphangioleiomyomas.. All five women experienced significant shrinkage or complete resolution of the lymphangioleiomyomas during treatment. In one woman, cessation of everolimus resulted in recurrence of symptoms. Adverse events were compatible with the known side-effect profile of everolimus, but overall the drug was well tolerated.. This is the first report to suggest that everolimus has efficacy in the treatment of lymphangioleiomyoma and chylous ascites in sLAM.

Topics: Abdominal Neoplasms; Adult; Antineoplastic Agents; Chylous Ascites; Drug Administration Schedule; Everolimus; Female; Humans; Lymphangioleiomyomatosis; Middle Aged; Respiratory Function Tests; Retrospective Studies; Sirolimus; Treatment Outcome

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive neoplasm that mostly occurs in young males. No curative treatment options currently exist for this type of tumor and long-term survival remains poor. In vitro rapamycin induces apoptotic death of JN-DSRCT-1 cells, a possible model for desmoplastic small round cell tumors in which the EWS gene is fused to the WT1 gene. We therefore demonstrate the prolonged activity of temsirolimus, an mTOR-inhibitor, in a patient with DSRCT.

Topics: Abdominal Neoplasms; Antineoplastic Agents; Humans; Liver Neoplasms; Lung Neoplasms; Lymphatic Metastasis; Male; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases; Young Adult