A subrenal capsule assay for testing the effect of anticancer drugs against human tumors.

Fresh surgical explants of solid tumors obtained from 50 patients were tested against six chemotherapeutic agents in the in vivo subrenal capsule assay. Control growth adequate to meet evaluable assay criteria was obtained in 36 of 50 tumors (72.0%). With activity criteria set at current drug screening levels as a change in modifidd PAPAN score in less than or equal to -2.0 for the SRC assay, 36.1% of the human tumors evaluable and 11.6% of drugs tested were sensitive, respectively. Our research reveals that gastric cancers respond to drugs about 2.5-fold higher than colorectal cancers. Comparisons were made of the drug sensitivity in terms of histologic differentiation, and it was strongly suggested that the sensitivity of the poorly differentiated type was higher than that of well or moderately differentiated type.