Characterization of Transplant Generations of Primary Rat Adenocarcinomas

DMBA-induced adenocarcinomas were transplanted into the neonatal or young rats of the same strain (Wistar). Following subcutaneous injection, tumors exhibited two phases of growth: an inititial avascular phase characterized by slow growth, followed by a later phase of rapid growth in which the tumor became vascularized. The transplanted tumor was more hypervascular than the primary tumor. Histologically, the primary autochthonous tumors and the transplanted counterparts were similar. The most striking result of transplantation was a much more homogeneous solid pattern than occurred in the primary tumor. The second histologic finding was a reduced stromal reaction. Moreover, in the central area of the tumor, the relationship between the vasculature and cell proliferation was observed. The transplanted tumors may provide a useful experimental model for laboratory studies on the chemotherapy of ovarian cancer.