Pubertal Growth, IGF-1, and Windows of Susceptibility: Puberty and Future Breast Cancer Risk

Purpose: Risk markers for breast cancer include earlier onset of menarche (age at menarche [AAM]) and peak height velocity (PHV). Insulin-like growth factor-1 (IGF-1) is associated with pubertal milestones, as well as cancer risk. This study examined the relationships between pubertal milestones associated with breast cancer risk and hormone changes in puberty. Methods: This is a longitudinal study of pubertal maturation in 183 girls, recruited at ages 6-7, followed up between 2004 and 2018. Measures included age at onset of puberty, and adult height attained; PHV; AAM; adult height, and serum IGF-1, and estrone-to-androstenedione (E:A) ratio. Results: PHV was greatest in early, and least in late maturing girls; length of the pubertal growth spurt was longest in early, and shortest in late maturing girls. Earlier AAM was related to greater PHV. IGF-1 concentrations tracked significantly during puberty; higher IGF-1 was related to earlier age of PHV, earlier AAM, greater PHV, and taller adult height. Greater E:A ratio was associated with earlier AAM. Conclusions: Factors driving the association of earlier menarche and pubertal growth with breast cancer risk may be explained through a unifying concept relating higher IGF-1 concentrations, greater lifelong estrogen exposure, and longer pubertal growth period, with an expanded pubertal window of susceptibility. (C) 2020 Society for Adolescent Health and Medicine. All rights reserved.

Automated summary

This study examined the relationships between risk markers for breast cancer, such as earlier onset of menarche and peak height velocity, with hormone changes in puberty. Results showed that early menarche and early maturing girls had greater PHV and higher IGF-1 concentrations. These factors may explain the association of earlier menarche and pubertal growth with breast cancer risk.