Putting this up for argument rather than for agreement. I have read it twice and I am still not certain what it supports.
Routine calcitonin screening is not recommended and does more harm than good in this population — the false-positive rate is high and the workup is invasive. The rodent medullary thyroid carcinoma signal that drives the labelling has not translated into a human signal, but a personal or family history of MTC or MEN2 is a genuine contraindication rather than a formality. Separately, TSH is worth having at baseline because hypothyroidism explains fatigue that people will otherwise blame on the drug.
Where I think it is weakest: the subgroup findings are the part I trust least — with enough subgroups something is always significant, and these were not all pre-registered.
The bit I cannot resolve on my own is why calcitonin screening is not recommended when the label carries a thyroid warning, because those two facts look contradictory from the outside. Not looking for reassurance. Looking for the part I have got wrong.
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.
rick_sfbay said:Routine calcitonin screening is not recommended and does more harm than good in this population — the false-positive rate is high and the workup is…
Thyroid cancer screening labs for thyroid monitoring — addressing the boxed warning concern with actual data:
Calcitonin level: 4.0 pg/mL (normal <10). Checked at baseline, month 6, and month 12. Rock stable, no upward trend.
Thyroid ultrasound: normal, no nodules at month 12.
The MTC risk from rodent studies has not been confirmed in human post-marketing data across millions of patient-years. The boxed warning is a regulatory precaution based on animal data. While monitoring is prudent, the clinical risk appears to be negligible.
rick_sfbay said:Routine calcitonin screening is not recommended and does more harm than good in this population — the false-positive rate is high and the workup is…
Pushing back on rick_sfbay here. I think the framing smuggles in the conclusion. Ask it the other way round and the obvious answer reverses, which usually means the question is doing the work.
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Shop Reference StandardsTaking the question as asked, rather than the general version of it. The version of this that has an answer is narrower than the version being asked. Narrow it and it becomes tractable; leave it broad and the thread will produce nine confident and incompatible replies.
DataDave said:Thyroid cancer screening labs for thyroid monitoring — addressing the boxed warning concern with actual data: Calcitonin level: 4.0 pg/mL (normal…
Adding a me-too, because a thread of one person's experience is not much use.