Women working night shifts at breast cancer risk
Women who regularly work into the early hours can be nearly four times as likely to develop breast cancer, scientist have warned.
The risk is highest among women who are naturally early risers. But even night owls are in danger.
The threat rose with the more night shifts they did, the study found.
And overall there was a 40 per cent bigger risk compared to women who worked days.
“The results indicate frequent night shift work increases the risk for breast cancer and suggest a higher risk with longer duration of night shift,” the Mirror quoted Dr Johnni Hansen, of the Danish Cancer Society that did the study, as saying.
“Those with morning preference tended to have a higher risk than those with evening preference,” Dr Hansen stated.
Women who worked nights three or more times a week for over six years were more than twice as likely to have the disease as those who had not.
What Are the Risk Factors for Breast Cancer?
A risk factor is anything that increases a person’s chance of getting a disease. Different cancers have different risk factors.
However, having a cancer risk factor, or even several of them, does not necessarily mean that a person will get cancer. Some women with one or more breast cancer risk factors never develop breast cancer, while most women with breast cancer have no apparent risk factors.
Significantly higher risk
A woman with a history of cancer in one breast is three to four times likelier to develop a new breast cancer, unrelated to the first one, in either the other breast or in another part of the same breast. This is different than a recurrence of the previous breast cancer.
Moderately higher risk
Getting older. Your risk for breast cancer increases as you age. About 77% of women diagnosed with breast cancer each year are over age 50, and almost 50% are age 65 and older. Consider this: In women 40 to 49 years of age, there is a one in 68 risk of developing breast cancer. In the 50 to 59 age group, that risk increases to one in 37.
Direct family history. Having a mother, sister, or daughter (“first-degree” relative) who has breast cancer puts a woman at higher risk for the disease. The risk is even greater if this relative developed breast cancer before menopause and had cancer in both breasts. Having one first-degree relative with breast cancer approximately doubles a woman’s risk, and having two first-degree relatives increases her risk fivefold. Having a male blood relative with breast cancer will also increase a woman’s risk of the disease.
Genetics. Carriers of alterations in either of two familial breast cancer genes called BRCA1 or BRCA2 are at higher risk. Women with an inherited alteration in either of these genes have up to an 85% chance of developing breast cancer in their lifetime.
Breast lesions. A previous breast biopsy result of atypical hyperplasia (lobular or ductal) or lobular carcinoma in situ increases a woman’s breast cancer risk by four to five times.
The risk almost quadrupled if they were early bird types - possibly because they are more susceptible to body clock disruption, said the study.
Night owls were twice as likely to have breast cancer, according to the findings published online in Occupational and Environmental Medicine.
The results were based on 692 responses, of which 141 were from women with the disease.
The study also indicated working up to two night shifts a week had no impact as it may not be long enough to disrupt the body clock.
Disturbing normal sleep patterns is thought to curb the cancer-protecting hormone melatonin, which is produced by the brain in the dark.
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The Times of India