Establishment of human colon carcinoma lines in nude mice.

After subcutaneous inoculation into nude mice of 24 human colon adenocarcinomas, growth, defined as histopathologically confirmed tumor growth which has been passed, was observed in 13 cases (54%). Tumors from metastatic sites showed higher take rates (58%) than tumors from primary sites or recurrent tumors (50%). Nine continuous tumor lines were established (69% of growing tumors) with metastatic tumors establishing more readily (100% of growing tumors) than primary tumors (40%). The average period in primary transplant was shorter for metastasis (8.3 weeks), than for primary tumors (18.5 weeks); total material 10.6 weeks. Average periods between passages were shorter than primary transplant times; these periods were shorter for metastases (6.6 weeks) than for primary tumors (9.4 weeks); total material 7.4 weeks. Of four growing tumors not established as continuous lines, three were primary and one a recurrent tumor, and the loss of tumor growth occurred in very early passages, not later than passage 3. All nude mouse-grown colon tumors were moderately well differentiated.