Select growth hormone regimen for childhood cancer survivors
STEP 1 — Gather Information
Confirm diagnosis of growth hormone deficiency via provocative testing (e.g., insulin tolerance test, glucagon) per guideline 2.3; verify at least 1 year disease‑free after completion of anticancer therapy; obtain baseline height, weight, pubertal status, and IGF‑I level; assess for contraindications (active malignancy, untreated central hypothyroidism or adrenal insufficiency, uncontrolled seizures).
STEP 2 — Rule In / Rule Out
Rule out active malignancy or disease‑free interval <1 year; rule out untreated severe hypothyroidism or adrenal insufficiency that must be corrected before GH initiation; rule out known hypersensitivity to somatropin.
STEP 3 — Classify or Stratify
Classify patient as eligible for GH therapy if GHD confirmed and disease‑free ≥1 year; note that dosing follows weight‑based regimens used in noncancer GHD (e.g., 0.024–0.03 mg/kg/day subcutaneously at night) and that spinal radiation may limit spinal height gain.
STEP 4 — Decide
Initiate GH therapy using standard noncancer regimens; monitor IGF‑I every 3–6 months and adjust dose to keep IGF‑I SDS within –2 to +2 for age, sex, and pubertal status; assess growth velocity every 6 months; evaluate for slipped capital femoral epiphysis, scoliosis progression, and intracranial hypertension periodically.
Clinical Guardrails / Mimics / Pitfalls
Do not start GH in patients with active malignancy or <1 year disease‑free; avoid exceeding IGF‑I SDS >+2 to reduce risk of adverse metabolic effects; monitor for slipped capital femoral epiphysis (especially in obese or rapidly growing adolescents) and worsening scoliosis; recognize that GH may improve limb length but not spinal height in those with spinal irradiation; ensure concomitant hormone deficiencies (TSH, ACTH, gonadotropins) are replaced.
Concrete Clinical Example
A 12‑year‑old male survivor of medulloblastoma received 24 Gy cranial radiation, completed therapy 2 years ago, has confirmed GHD (peak GH <5 µg/L on insulin tolerance test), IGF‑I SDS –2.5, no active disease. Start GH 0.03 mg/kg/day subcutaneously at night; after 4 months IGF‑I SDS –0.8, increase to 0.035 mg/kg/day; after 6 months growth velocity 6 cm/year; monitor IGF‑I every 4 months and watch for hip pain.
Source: Hypothalamic Pituitary and Growth Disorders in Survivors of Childhood Cancer, Sklar et al., Endocrine Society Clinical Practice Guideline, 2018, doi:10.1210/jc.2018-01175