DataDave 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: 2.0 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.

DanielChem_CHI said:

Thyroid cancer screening labs for thyroid monitoring — addressing the boxed warning concern with actual data: Calcitonin level: 2.0 pg/mL (normal…

Agreed on the substance. I would put less weight on the timescale, because two months of anything is not enough to distinguish a trend from a wobble.

DataDave 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.

Adding a me-too, because a thread of one person's experience is not much use.

From the other side of the consultation, briefly. The distinction that resolves most of these threads is between what is true on average and what is true for one person. Both are real; they answer different questions and get quoted as if they were the same one.