This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Talalay, P. Articles by Huggins, C. Search for Related Content PubMed PubMed Citation Articles by Talalay, P. Articles by Huggins, C.

Studies on the Walker Tumor^* I. Standardization of the Growth of a Transplantable Tumor

Paul Talalay, G. M. V. Takano and Charles Huggins

( Ben May Laboratory for Cancer Research, University of Chicago, Chicago, Ill.)

1. Factors contributing to the variability in growth rate of a transplantable tumor have been analyzed.

2. The Walker tumor was selected because it presents a malignant growth, to which there is 96 per cent susceptibility in either sex of albino rats of the Sprague-Dawley strain. Regressions are extremely rare, and the growth rate is reliable, reproducible, and rapid.

3. The most important factor contributing to variations in growth rate is the site of implantation. Subcutaneous implants show a large variability in size, depending upon whether the tumor becomes vascularized from muscle or skin. Uniform symmetrical growths may be obtained by resorting to bilateral intramuscular implantation into the flexor muscles of the thighs.

4. The growth rate of the tumor is not significantly affected by relatively large changes in the size of the inoculum.

5. In weaned rats, the size and sex of the animal do not influence the growth of the tumor but the carcass weight is greatly affected by the growth phase of the host animal.

^* This investigation was supported by grants from the American Cancer Society upon recommendation of the Committee on Growth of the National Research Council, and the Jane Coffin Childs Memorial Fund for Medical Research.

Senior Assistant Surgeon, Federal Security Agency, United States Public Health Service.

Received 7/ 1/52.