PharmacoVig_BOS said:

My prescriber wanted a baseline TSH and did not want a calcitonin, and I would like to understand the reasoning rather than just accepting it.

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.

Dr.BariatricHTX said:

Thyroid cancer screening labs for thyroid monitoring — addressing the boxed warning concern with actual data: Calcitonin level: 4.0 pg/mL (normal…

That holds where the measurement is reliable. Where it is noisy — and a lot of what gets tracked here is noisy — the same reasoning produces confident nonsense.

PharmacoVig_BOS said:

My prescriber wanted a baseline TSH and did not want a calcitonin, and I would like to understand the reasoning rather than just accepting it.

This matches mine closely enough to be worth saying so out loud. I had assumed I was the exception until I read this.

Adding the clinical framing, because it changes how the question reads. Most of what circulates confidently in this community traces back to one summary of one study, and the qualifier was dropped somewhere in the third retelling.