Expression patterns of cell cycle components in sporadic and neurofibromatosis type 1-related malignant peripheral nerve sheath tumors.

The molecular biology underlying the development of highly malignant peripheral nerve sheath tumors (MPNSTs) remains mostly unknown. In the present study, the expression pattern of 10 selected cell cycle components is investigated in a series of 15 MPNSTs from patients with (n = 9) or without (n = 5) neurofibromatosis type 1 (NF1). Thirteen tumors did not express the cyclin-dependent kinase inhibitor, p16(INK4A), an observation that was related to homozygote gene deletions in three tumors, heterozygote deletions in five, and gross gene rearrangements in five.

Multidrug resistance proteins in primary and metastatic soft-tissue sarcomas: down-regulation of P-glycoprotein during metastatic progression.

Background: Chemotherapy sensitivity of soft-tissue sarcomas (STS) is limited, which may be due to multidrug resistance (MDR). MDR is associated with expression of P-glycoprotein (P-gp), Multidrug Resistance-associated Protein 1 (MRP1) and Lung Resistance-related Protein (LRP). It is unknown whether in STS metastasis is more resistant than the primary counterpart.

Clinicopathologic assessment of postradiation sarcomas: KIT as a potential treatment target.

Purpose: Postradiation sarcoma, a sarcoma developing in a previously irradiated field, is a rare tumor. Surgery appears to be the only curative treatment option. In general the prognosis is poor, and new treatments options are needed.

Multidrug resistance proteins in rhabdomyosarcomas: comparison between children and adults.

Background: Pediatric rhabdomyosarcomas (RMS) have a more advantageous prognosis after multimodality treatment compared with adult RMS, which might be related to a decreased sensitivity to chemotherapy in adults. Resistance to chemotherapy might be conveyed by the multidrug resistance (MDR)-associated proteins P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), and lung resistance-related protein (LRP). It was therefore suggested that these proteins were expressed differently in pediatric and adult patients.

Metastasis in soft tissue sarcomas: prognostic criteria and treatment perspectives.

Soft tissue sarcomas (STSs) are rare tumors, notorious for early hematogenous metastasizing. Metastatic disease is seldom amenable to curative treatment; therefore new treatment modalities are required. Treatment-related and tumor-related prognostic factors can be assessed to estimate the risk for subsequent metastases, as will be discussed.