Growth characteristics of tumors induced by transplantation into athymic mice of BALB/3T3 cells transformed in vitro by residue organics from drinking water.

The growth and histopathological characteristics of tumors produced in nude mice by injection of morphologically transformed or normal BALB/3T3 1-13 cells were studied. Subcutaneous injection of 5 X 10(6) cells transformed in vitro by organic residue mixtures from samples of drinking water resulted in tumor growth in all animals with an average latency period of 25 days. Of the 13 animals receiving non-treated cells, three developed tumors with an average latency period of 127 days. Tumors grew progressively at the site of injection, reaching an average size of 1141 mm2 within 8-37 days. Most of the tumors, primarily those deriving from transformed cells, invaded the tumor bed and extended into the surrounding tissues. In few cases, extension of the tumor into the peritoneal cavity was observed. Microscopically all tumors were characterized as fibrosarcomas.