Prognostic and predictive value of c-erbB2 overexpression in osteogenic sarcoma. Osteogenic sarcoma (OS) is a highly malignant tumor of the bone. There are few reports in the literature regarding determination of c-erb B-2 (HER-2/neu) expression in cases of OS and also the results are quite variable.The present study was undertaken to correlate the expression of c-erbB2 with the survival of patients of OS.A retrospective study of cases of OS, in which the expression of c-erbB-2 by immunohistochemistry (IHC) was studied and correlated with the survival rate of the patients.Out of a total of 49 cases, proper follow up data in the form of total and disease free survival was available in only 20 cases. IHC for c-erb-B2 was carried out in these 20 cases.The staining pattern was as follows: no staining in 3 cases, 1 + in 5 cases, 2 + in 3 cases, 3 + in 3 cases and 4 + cytoplasmic positivity in 6 cases. Statistical analysis: Spearman rank correlation test was used to correlate the intensity of cytoplasmic staining of c-erbB-2 with survival rate of the patients, response to chemotherapy and metastasis.Previous studies have shown that c-erbB-2/HER-2 is an independent prognostic factor in osteogenic sarcoma, but in the present study, its expression was not seen to be correlating with survival rate of the patients. Therefore, further studies are needed to reach a consensus regarding the reliability of c-erbB-2 as an independent prognostic factor in OS.