Prognostic determinants in epithelioid sarcoma.

BACKGROUND: Epithelioid sarcoma (ES) is a rare soft tissue neoplasm that usually arises in the distal extremities of young adults, presents a high rate of recurrences and metastases and frequently poses diagnostic dilemmas. In order to identify markers useful for patient stratification purposes, we investigated the prognostic impact of clinical and molecular patient characteristics, including the status of SMARCB1 tumour suppressor gene, in a consecutive series of ES cases. METHODS: Kaplan-Meier survival curves were compared by the log-rank test. Immunophenotyping and SMARCB1 protein expression were analysed by immunohistochemistry or western blotting in 40 ES patients for which tumour material was available. Cases lacking SMARCB1 protein expression were investigated for the presence of gene mutations and gene deletions by exon sequencing, fluorescent in situ hybridization and quantitative PCR. RESULTS: FNCLCC tumour grade 3 and proximal-type histology significantly correlated with shorter overall survival (log-rank p=0.0046 and p=0.0001, respectively). We identified loss of SMARCB1 protein expression in the majority of ES cases (25/40, 62.5%), including 24/34 (71%) adult cases but only 1/6 (17%) paediatric/adolescent cases (p=0.02, two-tailed Fisher's exact test). The absence of protein is strongly correlated with SMARCB1 gene deletion (p=0.003, two-tailed Fisher's exact test). We observed a trend towards the correlation between SMARCB1 inactivation and both higher tumour grading and a clinical course of the disease characterised by the occurrence of multiple relapses/metastasis. CONCLUSION: These data show that both tumour grading and subtype are prognostic factors in ES. Loss of SMARCB1 protein expression in ES is a frequent occurrence mediated by gene deletion events, thus pointing to a crucial role of SMARCB1 in ES genesis. Analysis of SMARCB1 status in ES warrants prospective investigation as a prognostic marker and therapeutic target.

Fragile histidine triad gene inactivation in lung cancer: the European Early Lung Cancer project.

RATIONALE: Fragile histidine triad (FHIT) is a tumor suppressor gene involved in the pathogenesis of lung cancer. OBJECTIVES: The purpose of this study was to investigate the different molecular alterations leading to the inactivation of FHIT gene function and to validate their use as biomarkers of risk for progression of the disease in patients belonging to the multicentric European study for the Early detection of Lung Cancer (EUELC) who were resected for early-stage lung tumors. METHODS: FHIT immunostaining was performed on 305 tumor samples. The methylation status of FHIT promoter was assessed by nested methylation-specific polymerase chain reaction (MSP-PCR) in 232 tumor and 225 normal lung samples of which a subset of 187 patients had available normal/tumor DNA pairs. Loss of heterozygosity (LOH) at the FHIT locus was analyzed in 202 informative cases by D3S1300 and D3S1234 microsatellite markers. MEASUREMENTS AND MAIN RESULTS: Lost or reduced FHIT expression was found in 36.7 and 75.7% of the tumor samples, respectively. Methylation of the FHIT promoter was found in 36.7% of tumor and 32.7% of normal lung samples, whereas LOH was detected in 61.9% of the tumors. A strong association with complete loss of FHIT expression was present when methylation and LOH were analyzed together (P = 0.0064). Loss of FHIT protein expression was significantly more frequent in squamous cell carcinoma histotype (P < 0.0001) and in smokers (P = 0.008). FHIT methylation in normal lung was associated with an increased risk of progressive disease (OR, 2.27; P = 0.0415). CONCLUSIONS: Our results indicate that different molecular mechanisms interplay to inactivate FHIT expression and support the proposition that FHIT methylation in normal lung tissue could represent a prognostic marker for progressive disease.