Puberty timing linked to cancer

WEDNESDAY APRIL 26 2017

GIRLS typically start their periods at 12 or 13 while boys tend to see their voice break at 13 or 14. For every year a child starts puberty before this point, their cancer risk rises dramatically, a study has found. A girl of 11 going through puberty has a 28% higher chance of getting endometrial cancer, affecting the lining of the womb, than a girl of 12. The danger of getting breast cancer later in life rises 6% for each early year, while boys see their risk of prostate cancer go up by 9%.

The figures, from a University of Cambridge study, raise concern because many overweight children are now entering puberty early. The average age of puberty in the West is five years earlier than a century ago, with hormones feared to be triggered by modern fatty diets.

Senior author Dr John Perry said: “We have the best evidence yet that, broadly speaking, early puberty is bad for health.

“It leads to higher risks for breast cancer and may cause ovarian and prostate cancer too. That is because, when girls go through puberty early, typically age 9 or 10, this increases their lifetime exposure to circulating sex hormones like oestrogen. We think it is these hormones that fuel the growth of certain types of tumours and cause people to develop cancer.”

The study, published in the journal Nature Genetics, identified 389 genetic signals associated with puberty, four times the number previously known. Scientists mapped genetic variants from nearly 370 000 women and 110 000 men to discover the link with cancer. Women are at risk of three types of cancer if they have their first period early, possibly due to hormones such as oestrogen.

Longer hormone exposure is also why women who go through the menopause later are at greater risk of cancer. The study, also by scientists from the Reproductive Genetics Consortium, puts the risk of ovarian cancer up 8% for every year.

Perry said the findings should encourage parents to take action to make sure their children develop at an appropriate time.

He said: “But obese children have lots of energy reserves, so can trick their body into thinking they are ready to make the transition to puberty when in fact they are too young.” The study is the largest genomic analysis of puberty timing in men and women to date. It found that puberty timing often runs in families.” – Daily Mail