Breast cancer risk ‘not in­creased’ by night shifts

Malta Independent - - HEALTH -

Work­ing night shifts has “lit­tle or no ef­fect” on a woman’s risk of de­vel­op­ing breast cancer, new re­search sug­gests.

In 2007, a World Health Or­ga­ni­za­tion com­mit­tee said shift work “prob­a­bly” had a link to breast cancer, based on stud­ies of an­i­mals and peo­ple.

But this new work by lead­ing UK cancer ex­perts looked at data on 1.4m women and found there was no as­so­ci­a­tion with night shift work.

Cancer Re­search UK said it hoped the find­ings would re­as­sure women.

The In­ter­na­tional Agency for Re­search on Cancer made its rul­ing in 2007 be­cause of shift work’s dis­rup­tion to the body clock.

At that time there was lim­ited ev­i­dence about breast cancer risk in hu­mans, so the clas­si­fi­ca­tion was mainly based on a com­bi­na­tion of an­i­mal and lab stud­ies.

The new re­search is pub­lished in the Jour­nal of the Na­tional Cancer In­sti­tute.

Funded by the UK Health and Safety Ex­ec­u­tive, Cancer Re­search UK and the UK Med­i­cal Re­search Coun­cil, it looked at data from 10 dif­fer­ent stud­ies from the UK, USA, China, Swe­den and the Nether­lands.

Com­pared with women who had never worked night shifts, those who had done some overnight work - even for 20 to 30 years - had no in­creased risk of breast cancer.

The re­searchers found that the in­ci­dence of breast cancer was es­sen­tially the same whether some­one did no night shift work at all or did night shift work for sev­eral decades.

On av­er­age, 14% of women in the UK have ever worked nights and 2% have worked nights for 20 or more years.

Each year in the UK around 53,300 women are di­ag­nosed with breast cancer, and around 11,500 die from the dis­ease.

CRUK-funded sci­en­tist Dr Ruth Travis, who led the re­search and is based at the Univer­sity of Ox­ford, said: “We found that women who had worked night shifts, in­clud­ing long-term night shifts, were not more likely to de­velop breast cancer, ei­ther in the three new UK stud­ies or when we com­bined re­sults from all 10 stud­ies that had pub­lished rel­e­vant data.”

Sarah Wil­liams, CRUK’s health in­for­ma­tion man­ager, said: “This study is the largest of its kind and has found no link be­tween breast cancer and work­ing night shifts.

“Re­search over the past years sug­gest­ing there was a link has made big head­lines and we hope that to­day’s news re­as­sures women who work night shifts.

“Breast cancer is the most com­mon cancer in the UK and re­search to fully un­der­stand the dif­fer­ent risk fac­tors is vi­tal so that we can give women clear health ad­vice.

“Women can re­duce their risk of breast cancer by keep­ing a healthy weight, drink­ing less al­co­hol and be­ing ac­tive.”

Newspapers in English

Newspapers from Malta

© PressReader. All rights reserved.