1. Altered patterns of retinoblastoma gene product expression in adult soft-tissue sarcomas
- Author
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Martin S. Karpeh, Pollack D, Drobnjak M, Carlos Cordon-Cardo, Murray F. Brennan, Casper Es, Dudas Me, William G. Cance, E. Latres, and Woodruff Jm
- Subjects
Adult ,Male ,Cancer Research ,Pathology ,medicine.medical_specialty ,Tumor suppressor gene ,Soft Tissue Neoplasms ,Biology ,medicine.disease_cause ,Retinoblastoma Protein ,Gene product ,medicine ,Humans ,Genes, Retinoblastoma ,Survival rate ,Retinoblastoma ,Retinoblastoma protein ,Sarcoma ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Survival Rate ,Oncology ,biology.protein ,Female ,Carcinogenesis ,Research Article - Abstract
Altered expression of the retinoblastoma (RB) tumour-suppressor gene product (pRB) has been detected in sporadic bone and soft-tissue sarcomas. Earlier studies, analysing small cohorts of sarcoma patients, have suggested that these alterations are more commonly associated with high-grade tumours, metastatic lesions and poorer survival. This study was designed to re-examine the prevalence and clinical significance of altered pRB expression in a large and selected group of soft-tissue sarcomas from 174 adult patients. Representative tissue sections from these sarcomas were analysed by immunohistochemistry using a well-characterised anti-pRB monoclonal antibody. Tumours were considered to have a positive pRB phenotype only when pure nuclear staining was demonstrated, and cases were segregated into one of three groups. Group 1 (n = 36) were patients whose tumours have minimal or undetectable pRB nuclear staining (< 20% of tumour cells) and were considered pRB negative. Patients with tumours staining in a heterogeneous pattern (20-79% of tumour cells) were classified as group 2 (n = 99). The staining of group 3 (n = 39) was strongly positive with a homogeneous pRB nuclear immunoreactivity (80-100% of tumour cells). pRB alterations were frequently observed in both low- and high-grade lesions. Altered pRB expression did not correlate with known predictors of survival and was not itself an independent predictor of outcome in the long-term follow-up. These findings support earlier observations that alterations of pRB expression are common events in soft-tissue sarcomas; nevertheless, long-term follow-up results indicate that altered patterns of pRB expression do not influence clinical outcome of patients affected with soft-tissue sarcomas. It is postulated that RB alterations are primary events in human sarcomas and may be involved in tumorigenesis or early phases of tumour progression in these neoplasias.
- Published
- 1995