Tuesday, May 29, 2012

Breast cancer link to working nights: Three late shifts a week 'doubles the risk of disease'

Groan!  Who work night shifts?  Working class people.  Who have poorer health anyway?  Working class people.

Women who work night shifts are at higher risk of breast cancer, warn researchers.  Their findings suggest working at night increases the chances of the disease by 40 per cent.

Women working more than two night shifts a week have double the risk of those on day shifts, says a report from scientists, while night workers who also describe themselves as ‘morning people’ or ‘larks’ have a stronger risk than those who say they are ‘night owls’.

Experts believe a hormone in the body that potentially suppresses tumours may be disrupted by constant exposure to light during night-time hours.

There has been mounting evidence that night shifts might boost cancer risk because of the disruption to the body clock and hormone production.

The latest study, backed by the Danish Cancer Society, involved more than 18,500 women working for the Danish army between 1964 and 1999.

Researchers were able to contact 210 women out of a total of 218 who had breast cancer between 1990 and 2003 and who were still alive in 2005/06.

These women were matched with 899 women of the same age who had also worked for the Danish army but had not developed breast cancer.

The women completed a detailed questionnaire which included questions on their working patterns, use of the Pill and HRT, sunbathing habits and whether they classified themselves as a ‘morning’ or ‘evening’ person.

Overall, night shift work was linked with a 40 per cent increased risk of breast cancer compared with no night shifts. But women who had worked night shifts at least three times a week for at least six years were more than twice as likely to have contracted the disease as those who had not.

Those working this shift pattern for this length of time were even more likely to develop breast cancer if they were ‘morning’ types, says a report in the journal Occupational and Environmental Medicine.

They were almost four times as likely to have the disease as those who worked no night shifts, possibly because they are more susceptible to body clock disruption.

Researcher Johnni Hansen said the findings suggested that working up to two nights a week was not long enough to disrupt the body clock.

But frequent night shifts for several years may disrupt circadian rhythms – the body clock – and sleep patterns.
Night shift workers, such as the emergency services, have double the risk risk of breast cancer, new research suggests

Night shift workers, such as the emergency services, have double the risk risk of breast cancer, new research suggests

Exposure to light at night inhibits production of melatonin, which is produced by the pineal gland in the brain between the hours of 9pm and 8am. Melatonin, a hormone which dictates the natural cycles that govern sleep patterns, helps suppress tumours.

Research suggests that unusually low levels of melatonin, which are seen in people exposed to light during the night, may promote tumour growth.

Dr Rachel Greig, of the charity Breakthrough Breast Cancer, said: ‘It may be that night shifts themselves are not the only cause, as shift work can increase the likelihood of other lifestyle risk  factors, such as lack of exercise.

‘All women should cut back on alcohol, get regular physical activity and maintain a healthy diet to reduce their risk of breast cancer.’


Anti-psychotic drug also kills cancer

These findings in laboratory glassware generally lead nowhere but it may be a straw in the wind

A drug with a long list of heavy side effects, commonly used to treat sufferers of schizophrenia, also possesses some startlingly potent anti-cancer properties, according to research published Thursday in the medical journal Cell.

The drug, thioridazine, is usually dispensed as a last resort for schizophrenics whose symptoms did not respond to other treatments. Scientists said that after analyzing thousands of different drugs for possible anti-cancer effects, they discovered that thioridazine can be used to selectively target and eradicate cancerous stem cells present in leukemia, along with breast, blood, brain, prostate, ovarian, lung and gastrointestinal cancers, all without the worst side effects of today’s most frequently used cancer therapies.

“The unusual aspect of our finding is the way this human-ready drug actually kills cancer stem cells – by changing them into cells that are non-cancerous,” Mick Bhatia, the study’s principal researcher and scientific director of McMaster’s Stem Cell and Cancer Research Institute in Canada, said in a media advisory.

Bhatia’s team didn’t find the drug all on their own, however. In order to siphon up large amounts of previously unknown data on already-available drugs, they actually created a robotic stem cell screening system that analyzed thousands of different chemical compounds for potential effects on leukemia and breast cancer.

“We discovered the drug by creating a new way of looking at different chemicals,” he explained to MedicalXpress.com. “In order to do that, we have to put cancer stem cells in a dish, but also have normal stem cells to also test the compounds. We were able to do this with a robotic system, fully automated, that allowed us to go through 10 or 15 compounds [at first]. Now we can do this with thousands of compounds, eventually arriving at this drug that doesn’t do anything to normal stem cells, but kills cancer stem cells.”

The bad news: thioridazine is known to cause a wide variety of side effects in humans, including vomiting, constipation, swelling, slowed movements, the inability to produce facial expressions and sudden death from an irregular heartbeat — meaning the drug won’t get prescribed to cancer patients just yet.

However, scientists said that further study of how the drug interacts with cancer cells could broach a new frontier in cancer therapies, and noted that there are at least 12 other existing drugs that have “good potential for the same response.” They are still testing the drug’s effects on other types of cancers.

The McMaster advisory noted that Bhatia’s team hopes to begin human trials soon, and plans to test the drug first on leukemia patients whose cancer has returned after remission. They reportedly hope to learn whether thioridazine can also help prevent cancers from returning.


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