“Thelarche pathway” linked to obesity, possibly breast cancer

Girls who begin puberty with breast development before pubic hair growth are at increased risk for obesity and possibly also breast cancer, according to a report published in the June issue of the Journal of Pediatrics.

The findings are based on a study of 1166 preadolescent white girls who were followed with annual visits for 10 years. At each visit, puberty onset was assessed and height, weight, and skinfold measurements were taken.Approximately half of the girls experienced breast development and pubic hair growth at the same time. Of the remaining girls, about one third experienced pubic hair growth first, known as the “adrenarche pathway,” and two thirds experienced breast development first, known as the “thelarche pathway.”On average, girls in the thelarche pathway experienced menarche a few months earlier than those in the adrenarche pathway. Moreover, at the time of menarche as well as before and throughout puberty, thelarche pathway girls had greater body fat and BMIs than their adrenarche counterparts.”Epidemiological studies have noted a greater risk of breast cancer in those women who reported an earlier age of menarche,” lead author Dr. Frank M. Biro, from Children’s Hospital Medical Center in Cincinnati, Ohio, said in a statement. “There is also an association between breast cancer…greater BMI and body fat.”Therefore, in the current study, girls in the thelarche pathway had a number of factors that could increase their risk of breast cancer–earlier age of menarche, greater BMI, and increased body fat.As the study included only white girls, “it is unclear whether the impact of asynchronous maturation is the same in black females as it is in white female,” the authors note.(Source: J Pediatr 2003;142:000-000: Reuters Health: June 16, 2003: Oncolink)