Age years

Age (years)

Figure 5.8 a,b a Complete catch-up growth in a boy after cancer therapy. b Growth in a girl after cancer therapy, without catch-up growth. Normal percentiles (5th, 50th, and 95th, as shown) are obtained from the National Center for Chronic Disease Prevention and Health Promotion [38]

precocious puberty [39,40,58]. In girls, the first signs of puberty are a growth spurt and breast development (palpable breast buds or thelarche), followed by pubic hair growth and, after about 2 years, by menar-che. In boys, the first sign of puberty is testicular enlargement (testes length >2.5 cm), followed by penile and pubic hair growth, followed by a growth spurt. In most studies of normal children, pubertal milestones are attained at ages that are normally distributed, with a standard deviation (SD) of approximately lyear [69]. Children entering puberty more than 2 SDs earlier or later than average should be considered for endocrine evaluation. The average age that girls experience thelarche is 10 years, and the average age they experience menarche is 12.8 years; the average age when boys experience testicular growth is 11

Patients with gonadotropin deficiency may have a delayed, interrupted, or absent puberty. The staging of puberty is usually performed using the criteria of Tanner [69]. In survivors of childhood cancer, we initiate evaluation for delayed puberty in girls who show no onset of breast development by 12 years of age or no menarche by 14 years of age; we initiate evaluation for delayed puberty in boys who show no sign of testicular growth by 13 years of age. Boys treated with agents that can cause infertility may have in normal pubertal hormones but reduced testicular volume, due to damage to the seminiferous tubules and reduced sperm production.

years.

Height (cm)

Height (cm)

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