The study, by researchers at The Ohio State University Comprehensive Cancer Center Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, used microarray analysis to show that papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) differ in the expression of only four or five genes.
Distinguishing between the two cancers is important because the malignancies behave differently and require different treatment. The research should also help scientists better understand the origins of the two diseases. The study is published in the a recent issue of the Journal of Clinical Oncology.
"This finding suggests a potentially very useful diagnostic aid in those rare instances where the pathologist cannot distinguish between FTC and PTC," says study leader Charis Eng, the Dorothy E. Klotz Chair of Cancer Research and director of OSU's clinical cancer genetics program.
Thyroid cancer represents one percent of all cancers in the United States and is the most common cancer of the endocrine hormone system. Over the last few years, thyroid cancer has risen at an alarming rate, Eng says. An estimated 23,600 new cases of thyroid cancer are expected this year, nearly two-thirds of which will occur in women, and 1,460 Americans are expected to die from the disease. PTC represents about 80 percent of all thyroid cancers, with FTC representing about 10 percent of cases.
Eng and her colleagues have shown that two distinct groups of genes are either over-active or under-active in PTC cells compared with normal thyroid cells. Genes that were inactive or under-active were more typical of FTC cells.
They further found that five genes could distinguish the two tumor types.