35
Table 4. Endocrine Toxicities
Additional considerations:
• Please be aware of the need to start corticosteroids first when planning hormone
replacement therapy for multiple deficiencies as other hormones accelerate the
clearance of cortisol and can precipitate adrenal crisis.
• ACTH stimulation can give a false negative result early in hypophysitis as adrenal
reserve declines slowly after pituitary stimulation is lost. In the presence of clinical
uncertainty, opt for replacement and test for ongoing need at 3 months.
• If prednisone or equivalent is started for mild or moderate symptoms, consider lower
doses (average daily dose over two months of less than 7.5 mg ) due to report of
reduced survival on higher doses
• All patients need education on stress dosing for sick days, use of emergency steroid
injectables, when to seek medical attention for impending adrenal crisis, and a
medical alert bracelet for adrenal insufficiency to trigger stress dose corticosteroids
by EMS.
• Steroid use for other irAE's can cause isolated central adrenal insufficiency with a low
ACTH. In a patient with adrenal insufficiency, a recent history of treatment with
corticosteroids, and no other central hormone deficiencies, the HPA axis should be
tested for recovery after 3 months of maintenance therapy with hydrocortisone.
• Laboratory confirmation of AI should not be attempted in patients given high dose
corticosteroids for other irAEs until treatment is ready to be discontinued.
• AM cortisol in a patient on corticosteroids is not diagnostic as the measurement of
therapeutic steroids in the assay for cortisol varies. Hydrocortisone needs to be held
for 24 hours and other steroids for longer before endogenous function is assessed.
Consider consulting endocrinolog y for recovery and weaning protocols using
hydrocortisone in patients with symptoms of AI after weaning off corticosteroids.
4.4 Diabetes
Workup/Evaluation:
• Monitor patients for symptoms of new or worsening diabetes mellitus (DM)
(polyuria, polydipsia, fatigue).
• Monitor glucose at baseline and with each treatment cycle while on therapy and at
follow up visits for at least 6 months.
• Laboratory evaluation in suspected CIADM should include:
▶ Urine and/or serum ketones.
▶ Anion gap on a metabolic panel.
▶ Anti-GAD or anti-islet cell antibodies.
▶ C-peptide levels.
Grading Management
G1: Asymptomatic or mild
symptoms; Type 2 DM
(T2DM) with fasting glucose
value >ULN to 160 mg/dL
(>ULN to 8.9 mmol/L).
No evidence of CIADM such
as ketoacidosis or laboratory
evidence of pancreatic
autoimmunity.
• Can continue ICPi with close clinical follow-up
and laboratory evaluation.
• Refer to primary care practitioner (PCP) for
additional management or:
▶ May initiate oral therapy for those with new
onset T2DM.
▶ Intensify medical therapy for those with
worsening T2DM.
(cont'd)
