Pappy.

Papillary thyroid cancer (PTC) is an indolent disease, except when it’s not. A minority of histologies are deemed “aggressive variants” and are lumped together as a single intermediate-risk entity much the same as “soft tissue sarcoma.” That’s because non-well differentiated PTC subtypes face the same issue as sarcoma subtypes: rarity. This retrospective look at cancer registries aimed to compare four histologic subtypes, all falling under the “aggressive PTC” label, using well-differentiated and anaplastic histologies as reference bookends. As feared, prognoses varied drastically across the four subtypes with survival rates at 10 years clocking in at 79%, 72%, 45%, and 28%. Compare that to 85% for well-differentiated PTC and only 9% for anaplastic. TBL: Even though it is sure to make for a more complicated NCCN algorithm, papillary thyroid cancers that are neither well-differentiated nor anaplastic should be treated based on their (albeit rare) individual histology. | Ho, JAMA Oncol 2020