Abstract
The overexpression of HER-2 neu and p53 has been associated with poor outcome in many neoplasms. Their role in patients with osteosarcoma is unclear. We studied the expression of HER-2 neu and p53 in 22 osteosarcoma samples (from 20 patients-2 had locally recurrent disease) biopsied at the University of Medicine and Dentistry of New Jersey (UMDNJ) from 1996-2000 using both immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) analysis. Fourteen patients (14 samples) presented with Stage II and 6 patients (8 samples) presented with Stage III disease. Median follow-up is two years (range one year to five years). Four of 22 (18%) samples showed focal membranous or cytoplasmic positivity for HER-2 neu and six of 22 samples (27%) showed nuclear positivity for p53 by IHC analysis. In contrast, none of 22 tested samples showed gene amplification for HER-2 neu by FISH analysis. Seven of 13 HER-2 neu and p53 negative patients (54%) are currently disease free (between one year to five years). In this sample of patients, the HER-2 neu oncogene is not overexpressed or amplified in osteosarcoma; six of 22 samples (27%) showed overexpression of p53 by IHC analysis. By FISH, none of the samples demonstrated deletion of p53. Neither HER2 neu nor p53 expression was important for the biology of osteosarcoma in this population.