Pregnancy & Birth

New research shows that having a baby over the age of 35 increases your risk of breast cancer for the next two decades

The risk remains higher for 24 years.

By Elizabeth Bennett
An in­ter­na­tional overview of 15 stud­ies in­volv­ing nearly 900,000 women sug­gests that hav­ing a baby over the age of 35 means you're at a higher risk of developing breast can­cer for the next 24 years.
Five years af­ter hav­ing a child, moth­ers are 80 per cent more likely to get breast can­cer than women of the same age with­out chil­dren, The Times reported. It is thought that the huge hor­monal shift caused by preg­nancy and child­birth could in­crease the growth of mu­tat­ing cells, and sub­se­quently cause breast can­cer tu­mours to form.
Re­searchers have urged doc­tors to be made aware of their find­ings in or­der to of­fer the cor­rect care for moth­ers of young chil­dren in this age bracket.
Al­though start­ing a fam­ily in your late thir­ties may in­crease the short-term risk of breast can­cer, moth­ers still have a lower life­time risk of breast can­cer when com­pared to those who don't have chil­dren. This study found that 35 years af­ter giv­ing birth, women with chil­dren were 23 per cent less likely to get breast can­cer than child­less women of the same age.
While prior find­ings have been con­flict­ing when it comes to the ef­fect of child­birth on breast can­cer risk, it's been thought that it ini­tially raises the risk but then de­creases it. The point at which this shift takes place had pre­vi­ously not been iden­ti­fied but this new re­search re­view sug­gests that it takes 24 years af­ter the birth of a first child for a moth­ers' breast can­cer risk to de­crease be­low what it would have been had she never had chil­dren.
"What most peo­ple know is women who have chil­dren tend to have lower breast can­cer risk than women who have not, but that comes from what breast cancer looks like for women in their six­ties and be­yond. We found that it can take more than 20 years for child­birth to be­come pro­tec­tive for breast can­cer, and that be­fore that, breast can­cer risk was higher in women who had re­cently had a child," Hazel Nichols of the Uni­ver­sity of North Car­olina, one of the study's au­thors, com­mented.
In the past 25 years, breast can­cer rates have grown by a quar­ter. Si­mul­ta­ne­ously, dur­ing this pe­riod, the av­er­age age of a first-time mother has also increased from 28 to over 30. The link be­tween the two is­n't de­fin­i­tive, but as one of the study's other au­thors, Mi­nouk Schoe­maker of the Insti­tute of Can­cer Re­search in Lon­don, points out, it's cer­tainly a fac­tor to con­sider. She stated that an age­ing pop­u­la­tion and rise in obe­sity have also con­tributed to the ris­ing breast can­cer rates.
Re­as­sur­ingly, she said women should not be wor­ried about start­ing a fam­ily late, re­in­forc­ing that 60 per cent of breast can­cers oc­cur af­ter the age of 60, with the high­est risk for women in their eight­ies.
"If you have your first baby at 35 there is a risk for 24 years but most cases oc­cur af­ter that — by the time you reach the age where [breast can­cer] rates are much higher, your risk is re­duced com­pared with some­one who's never had a baby," she said.
Baroness Mor­gan of Drefe­lin, chief ex­ec­u­tive of Breast Can­cer Now, con­ceded this: "It's im­por­tant to re­mem­ber that younger women are at a much lower risk of breast can­cer. The longer term pro­tec­tive ef­fect of hav­ing chil­dren con­tin­ues well be­yond the menopause — when breast can­cer is more likely."
Via Grazia