Related Experiment Video
Updated: Aug 12, 2026

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
Published on: August 23, 2019
Molecular characteristics of isthmus papillary thyroid cancers: Supporting evidence for unfavorable clinical behavior
Eileen R Smith1, C Corbin Frye1, T K Pandian1
1Section of Surgical Oncology, Department of Surgery, Washington University, 660 South Euclid Ave., Saint Louis, Missouri 63110, USA.
Background:
Previous studies demonstrate isthmus thyroid nodules are more likely to be malignant than lobar nodules. Additional data suggest that isthmus papillary thyroid cancers (PTCs) are more aggressive than lobar PTCs. We hypothesize that isthmus PTCs have a more unfavorable molecular profile.
Methods:
The Cancer Genome Atlas (TCGA) database was queried to analyze clinical, mutation and gene expression data of isthmus PTCs compared to non-isthmus PTCs.
Results:
We analyzed characteristics of 472 PTCs, including 19 isthmus PTCs. There were no significant differences between isthmus and non-isthmus PTC demographic and clinical variables or the frequency of RAS family, fusion driver, TERT, and tumor suppressor gene mutations. There was a trend towards increased BRAF mutations (68% vs 55%, p = 0.28). A more aggressive gene expression profile was observed in isthmus PTC compared to lobar/multifocal PTC with differences in ERK score (19.4 vs 7.71, p < 0.05) and TDS score (-0.58 vs 0.02, p < 0.05).
Conclusions:
These results provide a possible molecular explanation for the more aggressive behavior reported in isthmus PTCs.
Related Concept Videos
Tumor Progression
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
The Tumor Microenvironment

