Figure 2.
The phenotype of papillary thyroid cancer is ameliorated by pre-existing thyroiditis. (A) Survival curve of the 31 mice in the lifetime cohort injected with tamoxifen, according to the experimental group. Overall survival is compared by the log rank test; median survival (dashed line) by Laplace regression. (B) Incidence of papillary thyroid cancer in all 113 NOD.H2h4_TPO-CRE-ER_BRAFV600E mice featured in the study, according to cohort type (lifetime or 16 weeks), experimental group [concomitant, pre-existing, or no iodine-exacerbated thyroiditis (IET)], and injection type (tamoxifen or corn oil). Differences in the distribution of incidence were compared by chi-squared test. (C) Severity of papillary thyroid cancer (PTC) in the 50 mice of the lifetime cohort. (D) Severity of PTC in the 63 mice of the 16-week cohort. Severity was expressed as percent of the total thyroid area involved by PTC. Comparisons among groups were done Kruskal Wallis test, followed by the Wilcoxon rank sum test for pairwise assessments.