Leiomyosarcoma and synovial cell sarcoma are two of the most common malignant soft tissue tumors. Despite survival rates have improved in the past two decades due to advanced treatment with primary radical surgery, along with chemotherapy and radiation, long term prognosis continues to be poor. For instance, synovial sarcoma patients with non-metastatic surgically resected disease are reported to have a 5-year overall survival and the 5-year metastasis-free survival of not more than 71% and 51%, respectively [
1]. These survival rates did only tend to result in better outcomes if chemotherapy was performed; clearly underscoring the absolute need for identification of prognostic relevant factors. These factors, possibly assisting in prediction of disease specific prognosis, may help to evaluate the risk for local and systemic recurrence and allow stratifying patients to different treatment strategies.
Among those factors survivin has attracted major interest as it was shown to be strongly overexpressed in a vast majority of cancers, and it is one of the most tumor-specific human gene products [
2]. Survivin belongs to two major protein families, the inhibitor of apoptosis and the chromosomal passenger families thereby playing an important role for both regulation of cell death and of cytokinesis [
3‐
7]. Recently, survivin has been considered as putative stem cell marker (reviewed in [
8]). A correlation between survivin detection and prognosis of tumor patients has been described for many different cancers (reviewed in [
9]). However, there are also reports indicating survivin expression is a favourable prognostic marker (reviewed in [
10]). Only a few studies investigated the correlation of survivin protein expression with prognosis in sarcomas as it has been described as prognostic marker for osteosarcomas [
11‐
13]. Nuclear localization of survivin expression was significantly correlated with a prolonged survival but cytoplasmic staining showed no correlation with patients' outcome [
11]. In contrast, in another study, survivin expression was significantly associated with the PCNA-labelling index, which was correlated with the histological grades of osteosarcoma [
12]. This result rather confirms a role of survivin in inhibiting apoptosis and affecting tumor progression [
13]. We investigated survivin expression on the RNA level (qRT-PCR) and on the protein level (ELISA, Western hybridization) in a group of different soft tissue sarcomas including a few leiomyosarcomas and synovial sarcomas, previously. Elevated survivin RNA and protein level were significantly correlated with a poor prognosis of STS patients [
9,
14]. RNA-Expression of survivin and two other stem cell-associated genes (Hiwi, hTERT) was correlated with a 15.5-fold increased risk of tumor-related death for soft tissue sarcoma patients [
15]. There are only two reports that studied survivin protein expression in soft tissue sarcomas by immunohistochemistry but without correlating results with prognosis [
16,
17]. Caldas et al. could show that over 80% of primary rhabdomyosarcoma tumors expressed survivin and Tabone-Eglinger et al. found survivin protein expressed in all investigated malignant peripheral nerve sheath tumors [
16,
17]. This study aimed for the first time to analyse expression of survivin protein in the soft tissue entities leiomyosarcoma and synovial sarcoma by immunohistochemistry. In addition, to evaluate the prognostic impact of survivin-expression either detected in the cytoplasm or in the nucleus for leiomyosarcoma and synovial sarcoma patients.