Prognostic factors and analysis of S100aS protein in resected pulmonary metastases from renal cell carcinoma

Background This study analyzes our experience withpulmonary resection for metastases from renal cell carcinoma.The goals were to search for factors influencingprognosis and to investigate the presence and the prognosticvalue of S100A4 protein in lung metastases andcorresponding primary renal tumors.Methods Sixty-five patients underwent surgical resectionfor renal and pulmonary lesions between 1992 and 2007.S100A4 protein expression was immunohistochemicallyexamined in the peritumoral infiltrate of 64 lesions (32metastases and the 32 corresponding primary carcinomas).Results Overall 3-, 5-, and 10-year survival rates were 58,46, and 25%, respectively. Univariate analysis revealedthat surgical radicality (p = 0.0039) and stratification intogroups according to the International Registry of LungMetastases classification (p = 0.0137) were prognosticfactors. Multivariate analysis confirmed that this classificationwas a significant prognostic factor (p = 0.01). Allmetastases and the corresponding primary carcinomasexpressed S100A4 protein. Twenty-one metastases (66%)had weak expression and 11 (34%) had strong expression.Twelve (37.5%) primary lesions had weak expression and20 (62.5%) had strong expression. The 5-year survival ratefor patients with strong expression in primary carcinomawas 41%, significantly lower than that of patients withweak expression (78%; p = 0.05).Conclusions Pulmonary resection in metastatic renal cellcarcinoma results in long-term survival. Complete resectionand stratification into groups according to the InternationalRegistry of Lung Metastases classification wereprognostic factors. Overexpression of S100A4 protein inprimary tumors was correlated with a poor prognosis. Ifconfirmed in larger studies this finding could be used toschedule adjuvant treatments in patients undergoingnephrectomy for renal cell carcinoma.