In a study on the long-term effects of dietary diethylstilbestrol or 17 beta-estradiol on C3H mice, estrogens induced a proliferation of osseous trabeculae and increased the incidence and hastened the development of osteofibrotic areas in the sterna.
There were 6 osteosarcomas, 2 having metastases, in 1,242 mice fed dietary estrogens over 360 days, but none in 356 untreated controls.
Osseous changes and osteosacomas in mice continuously fed diets containing diethylstilbestrol or 17 beta-estradiol, Journal of the National Cancer Institute, NCBI PubMed PMID: 6944535, 1981 Sep.
These tumors were reviewed along with 4 early sternal osteosarcomas selected from 17 osteosarcomas (only 1 in a control) found thus in two other ongoing comparable studies.
In at least 1 case, and possibly in 2 other early cases, tumors were associated with areas of osteofibrosis, and 1 tumor was probably associated with proliferation of bony trabeculae in the medullary cavity.