skip to main content

C-peptide ICI T1DM — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

HardMelanoma & SkinC-peptide ICI T1DMSCE Medical Oncology

A 65-year-old man with metastatic melanoma on nivolumab develops new-onset type 1 diabetes presenting with DKA. After stabilisation on insulin, his endocrinologist checks C-peptide. It is undetectable. What does this confirm?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Complete immune-mediated beta-cell destruction — undetectable C-peptide confirms absent endogenous insulin production; LIFELONG insulin replacement is required; unlike other irAEs, this is IRREVERSIBLE; corticosteroids do NOT restore beta-cell function

ICI-T1DM: C-peptide undetectable = complete beta-cell destruction. Irreversible. Lifelong insulin. Steroids do NOT restore function (unlike most irAEs). ICI can continue once diabetes stable on insulin.

Reference: ESMO 2024 irAE; de Filette et al Eur J Endocrinol 2019