Biological features and chemosensitivity of human colorectal cancer xenografted in nude mice.

The chemosensitivity of human colorectal cancer was studied in relation to the biological features of the tumor using a human tumor/nude mouse in-vivo system. The biological features included the histological type, growth rate, mucus secretion and productivity of CEA of the tumor. The overall sensitivity to four anticancer agents examined (5-FU, MMC, CPA and CDDP) was relatively insignificant. The heterogeneity of chemosensitivity among primary, metastatic and recurrent lesions of the same patient was demonstrated. A tumor line obtained from poorly differentiated adenocarcinoma showed better responses to 3 of 4 agents. Tumor doubling time evaluated as an indicator of tumor growth rate showed a significant correlation with sensitivity to MMC. The time also showed a tendency to correlate with sensitivity to CDDP. The tumor with shorter tumor doubling time presented had more remarkable sensitivity to such agents. Similar correlation was observed in the mucus secretion shown by Alcian-blue (AB) staining and sensitivity to MMC and CDDP. Tumors with less significant AB staining showed more remarkable sensitivity to these agents. The productivity of CEA revealed a tendency to correlate with sensitivity to MMC and CPA. These results indicated that histological type, growth rate, mucus secretion by AB staining and productivity of CEA of the tumor might be parameters of chemosensitive differences of human colorectal cancer.