S. Duensing et al., IMMUNOCYTOCHEMICAL DETECTION OF P-GLYCOPROTEIN - INITIAL EXPRESSION CORRELATES WITH SURVIVAL IN RENAL-CELL CARCINOMA PATIENTS, Oncology, 51(4), 1994, pp. 309-313
We evaluated 28 patients with advanced renal cell carcinoma for the in
itial expression of P-glycoprotein (MDR1 gene product) employing immun
ocytochemistry. Tumor specimens were obtained upon primary tumor nephr
ectomy. In all patients, progression-free survival time following neph
rectomy was evaluated and correlated statistically with the staining r
esults. Progression-free survival of patients with no or very few (< 1
%) P-glycoprotein-positive tumor cells (n = 8, median survival 27.0 mo
nths) was significantly extended (p < 0.04) as compared to patients wi
th 1% or more P-glycoprotein-positive tumor cells (n = 20, median surv
ival 4.0 months). Correlations with histopathological tumor characteri
stics were insignificant. These results suggest a potential role for P
-glycoprotein as a biologic parameter predictive of tumor progression
in renal cell carcinoma patients.