Abstract
Tumor lines of human colorectal cancer heterotransplanted serially in nude mice were subjected to the present study on growth rate of the tumor. Histology of primary tumors included well, moderately or poorly differentiated adenocarcinoma, mucinous carcinoma and signet ring cell carcinoma. The results obtained were as follws;
1. Doubling time of these tumor lines ranged from 5.1 days to 16.9 days (mean; 10.2 days).
2. Growth rate of poorly differentiated adenocarcinoma was fast, compared with that of mucinous carcinoma or signent ring cell carcinoma.
3. Growth rate of liver metastatic lesion was faster than that of primary lesion, whereas reverse relationship was observed in that of lymph node metastatic lesion.
4. Serum carcinoembryonic antigen (CEA) levels were related to growth rates of the tumor line.
5. Growth rate of each tumor line was correlated with its chemosensitivity against Mitomycin C.
These results indicate that growth rate of human colorectal cancer is related to histology of the primary tumor, type of the lesion (primary or metastatic), serum CEA level and sensitivity to anti-cancer drugs.
