Scientists explore how thyroid cancer metastasizes, often staying dormant for years
Distant metastases of thyroid cancer can dramatically reduce a patient's likelihood of survival, which is one reason why a scientist at the Ohio State University College of Medicine recently reviewed the current clinical understanding of how thyroid carcinoma cells migrate.
Dr. Matthew Ringel, who also hails from the Arthur G. James Comprehensive Cancer Center, stated that a number of factors can influence the metastasis of thyroid cancer, but that the disease appears to be able to spread at nearly any stage.
Ringel's review, which appeared in the journal Thyroid
, traced the study of metastasis back to 1889, when English pathologist Stephen Paget described cancer migration using a "seed and soil" model.
Today, this analogy is still widely used, according to a review published in the journal Clinical and Experimental Medicine
. That said, in the past century, researchers have added significantly to the collective knowledge about how thyroid cancer spreads.
Ringel noted that the migration of thyroid tumor cells to other parts of the body can be thought of in terms of short dormancy or long dormancy.
Short-dormant metastases involve the mutation of thyroid cancer epithelial cells into those that can grow into a number of different cell types. These cells escape into the bloodstream, stick in different organ systems and begin growing almost immediately.
The study's author noted that short-dormant metastatic cells tend to be organ-specific. For instance, while medullary thyroid cancer often metastasizes in the liver and bones, papillary thyroid cancer usually migrates to the lungs or brain, he wrote.
By contrast, long dormancy is a more recently observed phenomenon. Ringel stated that once embedded in a distant organ system, long-dormant thyroid cancer cells may wait for months or years before rapidly multiplying, due to either genetic variations, immune activity or the cellular microenvironment.
The endocrinologist added that different varieties of the disease tend to be short- or long-dormant.
He specified that anaplastic, invasive papillary and invasive follicular thyroid cancers often spread quickly, while metastases of well-differentiated forms of the condition may experience long periods of dormancy.