Greater Identification is Leveling off Thyroid Cancer Rates in U.S.
HealthDay News — Fewer thyroid cancers are diagnosed in the United States now than in the recent past, perhaps signaling a change in physician practices, according to a report published online April 14 in JAMA Otolaryngology-Head & Neck Surgery.
Luc Morris, MD, surgical oncologist at the Memorial Sloan Kettering Cancer Center in New York City, and colleagues tracked thyroid cancer cases in the United States from 1983 to 2012. Incidence increased 3% a year from 1988 to 1998. Over the next decade, the trend more than doubled, reaching 6.7% annually, then leveled off at 1.75%.
"Up to 30% of healthy persons have small cancers in their thyroid glands, and nearly all of these would not go on to cause any problems for the person if the cancer were never discovered," Morris told HealthDay. They've always been present, "like a huge submerged iceberg, but we are just getting better at finding them," he noted. That explains why the dramatic jump in thyroid cancer is best described as an "epidemic of diagnosis," not an epidemic of disease, he added.
In another report published online April 14 in JAMA Oncology, researchers announced that one type of thyroid cancer has been reclassified to reflect it is noninvasive and has a low risk of recurrence. The name change applies to encapsulated follicular variant of papillary thyroid carcinoma, which accounts for 10 to 20% of all thyroid cancers diagnosed in Europe and North America, the researchers noted. The new name, "noninvasive follicular thyroid neoplasm with papillary-like nuclear features," keeps key features to aid pathologists in diagnosis, but indicates that it need not be treated aggressively.