Relative Role of Host and tumor in the Growth Pattern of Murine and Human Neoplasms following Subcutaneous Transplantation in Mice

The growth patterns of two murine and eight human tumors, bilaterally implanted into subcutaneous tissue of groups of recipient mice, were studied. A Gompertz equation was fitted to experimental data for each individual implant and the Gompertz parameters were utilized as quantitative growth characteristics. The relative roles of the tumor-implanted flank (right versus left), of the individual host and of the tumor were analyzed by the paired t-test, simple linear regression model, one-way and two-way analysis of variance. Sixty pairs of Gompertz curves were obtained in seventy animals. Heterogeneity was the main characteristic of the growth pattern in all tumors under study, with a wide variability among the Gompertz parameters. Statistical analysis of experimental data showed that only the tumor systematically influenced the growth characteristics, whereas neither the tumor-implanted flank nor the individual host played a significant role. These results have both theoretical and practical implications.