PROGNOSTIC RELEVANCE OF THE INTRINSIC GROWTH DECELERATION OF THE FIRST PASSAGE XENOGRAFTS OF HUMAN RENAL-CELL CARCINOMAS

BACKGROUND. Although successful xenotransplantation of human tumors in nude mice highly predicts prognosis, little is known regarding the bi ologic background of this correlation. In this study, the relationship between the macroscopic growth pattern of first-generation xenografts of human renal cell carcinomas in nude mice and prognosis was studied . METHODS. Macroscopic growth patterns of the first-generation xenogra fts of locally confined renal cell carcinomas were analyzed according to the best-fit Gompertz recursion formulas. RESULTS. The parameter '' b'' of the growth pattern, the measure of the intensity of growth dece leration as a function of tumor growth, strongly predicted prognosis a fter nephrectomy as a single factor; faster growth deceleration, i.e., lower b values, predicted better prognosis (mean follow-up, 5.2 years ; P = 0.000008 for the disease free period and P = 0.000018 for overal l survival). It is also the most significant single prognostic paramet er among others (including staging and grading) according to a multiva riate analysis. CONCLUSIONS. The parameter expressing the Gompertzian macroscopic growth deceleration of the first-generation xenografts of clinically locally confined renal cell carcinomas in nude mice explain s the strong prognostic impact of xenotransplantation. (C) 1996 Americ an Cancer Society.