Smoking And Breast Cancer: Cigarettes Now A Risk To Your Breasts?

Women who smoke have an increased risk of developing breast cancer, especially if they become smokers early in life, a new study suggests.

But the added risk appears to be small, except among heavy smokers. Compared with women who had never smoked, those who were regular smokers for any amount of time had a six percent higher risk of developing breast cancer, the study found. Women who maintained a pack-a-day habit for at least 30 years had a 28 percent higher risk, however.

"I would not put [smoking] on the list of important risk factors, [but] when you look at the subgroup of heavy-duty smokers who start early and smoke for a long time, that's more serious," says the lead author of the study, Karin Michels, Ph.D., an associate professor of cancer epidemiology and ob-gyn at Harvard Medical School, in Boston. "That's when you pay closer attention."

Previous studies on smoking and breast cancer have had mixed results. Some have found that smoking increases risk, some have found it has no effect, and some have even linked cigarette smoking to a lower risk of breast cancer.

More From Health.com:
10 Crazy Ways Smokers Finally Kicked the Habit
5 Simple Things That Could Cut Your Breast Cancer Risk
15 Ways Smoking Ruins Your Looks

While cigarette smoke is a potent carcinogen, smoking also lowers levels of estrogen -- one of the primary fuels that drive the growth of breast cancer. "The reason why previous studies may not have found strong associations or any association could be because the two effects may cancel each other out," Michels says.

In the study, which appears in the Archives of Internal Medicine, Michels and her colleagues looked at 30 years of data on more than 110,000 women who were part of the government-funded Nurses' Health Study.

In all, the study participants reported 8,772 cases of invasive breast cancer during that timeframe.

Although the increase in breast cancer risk associated with smoking was just six percent overall, some subcategories of women -- such as those who smoked before their first child was born -- were at slightly higher risk. (Having children at an early age is believed to protect against breast cancer, perhaps because of changes that occur in the breast tissue.)

"It's not surprising that the risk was so low, because breast cancer is driven by hormonal factors," says Joanne Mortimer, M.D., director of the Women's Cancer Program at City of Hope Cancer Center, in Duarte, California. "The risk for breast cancer seems to be in the hormone transition period between premenopause and postmenopause, when there are a lot of changes in hormone functions." (Mortimer was not involved in the new research)

In fact, women who smoked after menopause appeared to have a decreased risk of breast cancer compared with nonsmokers. Given that both menopause and smoking lower estrogen levels, this finding adds to the evidence that estrogen is a risk factor for invasive breast cancer, the authors say.

The findings, of course, don't mean that the considerable health risks associated with smoking should be overlooked, says Debra Monticciolo, M.D., a professor of radiology at Texas A&M Health Science Center College of Medicine, in Temple.

Although smoking "is not going to be a major player in our assessment of risk for breast cancer," Monticciolo says, "there are lots of reasons not to smoke. I can't think of anything good to come from smoking."

Comments

[mssreader]

12:19 AM on 01/27/2011

It's interesting that I work with 11 women and have for 16 years and during that time there have been but two women diagnosed with b/cancer and that happened last year within months of each other and interesting that in all the years those two are the only ones who have smoked. And unfortunately they are still smoking.

[Chuck Bluestein]

06:39 PM on 01/26/2011

Cardiologists say that smoking is the biggest contributor to heart attacks. Neurosurgeons say that smoking is the biggest contrbuting factor for having strokes. So it does not matter much about the cancer especially if people make sure to have lifeguard levels of vitamin D in their blood. Moores Cancer Center is proposing that cancer is actually a vitamin D deficiency. http://bit.ly/can-cer

Also smoking makes people more stressful since they need to get their next fix. There was an article about incontinence on here with a picture of a woman wearing a thong. That has to be stressful when you are in need of finding a bathroom fast. Sometimes the smoker is desperately seeking a place to smoke before he or she goes crazy. I have witnessed this many times.

[kd1s]

05:51 PM on 01/26/2011

I wish the tobacco companies had been sued out of existence way back in the 1950's. Maybe then my mother wouldn't have suffered in her very early 30's from breast cancer that metastasized to her brain, lungs, and liver, ultimately killing her.

[babybecks]

03:48 PM on 01/30/2011

Sorry to hear that.

[stape45]

03:15 PM on 01/26/2011

Cigarettes are very damaging to the smokers’ health, but very enriching to the capitalists that flood the market with them.

[stape45]

03:10 PM on 01/26/2011

Smoke containing added toxins and carcinogens, is detrimental to the health. Anyone in denial out there?

[stape45]

03:05 PM on 01/26/2011

Why don't they just outlaw cigarettes, if they're as bad as they say? That was a rhetorical question, of course. I know this is a purely capitalist (to a fault) society.

[mssreader]

12:25 AM on 01/27/2011

stape, they can't outlaw cigarettes any more than they could outlaw sugar and alcohol. I would like to see huge taxes on cigarettes and let those taxes go to help pay for the medical costs of those who smoke. I know this has been done in some states but I don't think the taxes are high enough. I lost my father and baby brother to lung cancer. Both were heavy smokers from a young age.

[reader110]

07:39 AM on 01/26/2011

Breaking news - smoking may or may not cause breast cancer. Also breaking - non-smokers may get breast cancer, too.

Yawn.