Smoking Linked to Breast Cancer Risk

Smoking Linked to Breast Cancer Risk

John (Gold)
Joined: 18 Dec 2008, 23:57

11 May 2001, 05:33 #1

http://dailynews.yahoo.com/h/nm/2001050 ... ast_1.html

Wednesday May 9 6:36 PM ET
Cigarette Smoking Linked to Breast Cancer Risk


By Will Boggs, MD

NEW YORK (Reuters Health) - Smoking is a major risk factor for breast cancer among women with a family history of breast or ovarian cancer, US researchers report.

Their study of 132 families with at least three breast or ovarian cancer patients found that patients' sisters and daughters who smoked were more than twice as likely to develop breast cancer, compared with the nonsmoking sisters and daughters of patients.

Smoking did not appear to increase the risk among patients' nieces and granddaughters, however, according to the report published in the April issue of Cancer Epidemiology, Biomarkers & Prevention.

In families with the strongest genetic risk--those with at least five members with cancer--smoking was an even more significant risk factor. Patients' sisters and daughters who smoked at some point in their lives were nearly six times more likely to develop breast cancer than relatives who never smoked.

``Breast cancer is not typically thought of as a smoking-associated malignancy but for susceptible women it could be quite an important contributor,'' Dr. Thomas A. Sellers of the Mayo Clinic in Rochester, Minnesota, and the study's senior author, told Reuters Health.

The researchers explain that smoking boosts carcinogens, or cancer-causing chemicals, in the blood. These chemicals can cause mutations in the DNA of breast cells which, over time, lead to cancer.

The study authors call for further research into the link between cigarette smoking and breast cancer among women with a genetic risk.

``If you don't smoke, don't start. If you do smoke, it's never too late to quit,'' Sellers said.

SOURCE: Cancer Epidemiology, Biomarkers & Prevention 2001;10:327-332.
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John (Gold)
Joined: 18 Dec 2008, 23:57

11 May 2001, 05:39 #2

http://www2.cancer.org/zine/index.cfm?fn=001_05032001_0

Today's Date: May 10, 2001


Tobacco Use, Genetics May Increase Breast Cancer Risk


May 3, 2001 (ACS NewsToday) --- Smoking may put women with a family history of breast and ovarian cancers at greater risk of developing breast cancer themselves, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, (Vol. 10, No. 4: 327-332).

The multigenerational study contradicts a May 1998 paper published in the Journal of the National Cancer Institute that suggested tobacco might be a protective factor, reducing the risk of breast cancer in women with the mutant BRCA1 or BRCA2 gene, an inherited defect associated with higher risk for breast and ovarian cancers. It is not clear why tobacco may have been considered protective, although some investigators believed it may have been due to decreased estrogen levels in women who were smokers.

"The most important finding was that smoking did not lower the risk of breast cancer in high-risk families," says the new paper's senior author, Thomas A. Sellers, PhD, an epidemiologist and associate director of the Mayo cancer center. "This is one more reason to avoid smoking."

In this study, researchers from the Mayo Clinic Cancer Center looked at breast and ovarian cancer cases in female relatives of 426 women whose families had a high incidence of those cancers, and who had been diagnosed with breast cancer between 1944 and 1952.

The researchers analyzed a subgroup of 132 families that had at least three cases of breast or ovarian cancers by the end of the follow-up period of 1991 to 1996. Among the sisters and daughters in these higher-risk families, those who smoked were at a 2.4-fold increased risk of breast cancer over those who had never smoked. (Sisters and daughters share 50% of the genes of the original cancer patient.)

In 35 families with the highest genetic risk - that is, there were at least five cases of breast or ovarian cancers in the family history - sisters and daughters who smoked had more than double the risk of developing breast cancer than the nonsmokers. The increased risk among smoking granddaughters and nieces-who share 25% of the original patient's genes-was 1.7-fold.

Small group of highest-risk patients weakens the conclusion

The data linking cigarette smoking and breast cancer are mixed, with most published studies finding a weak link. Marilyn Leitch, MD, a member of the American Cancer Society breast cancer council and medical director at the University of Texas Southwestern Center for Breast Care, cautions that the number of families in the highest-risk genetic group - 35 - is small, making it difficult to conclude with certainty that smoking definitely increases the risk of developing breast cancer in predisposed women with positive family histories.

"The smokers were more likely to drink alcohol," says Leitch, "which is also shown to be a risk factor for development of breast cancer."

At the Mayo Clinic, Sellers offers two possible reasons for why his study, found an apparent link to the disease. This study is the first to look at multiple generations of families with breast cancer, he says. If smoking is more dangerous for a certain group of susceptible women, previous studies may have missed the thread of that inherited susceptibility, Seller says. Secondly, the age at which women begin smoking has dropped dramatically during 30 years of breast cancer research, he says.

"In 2001, 95% of all smokers begin before age 18," says Sellers. "So if women are exposed during adolescence when breast tissues are growing and dividing rapidly, that may be a more critical period."

He expected to find that if smoking actually increased the risk of breast cancer, as it does in lung cancer, the more women smoked and the longer they smoked, the greater the risk of developing breast cancer. The Mayo group did not see that, however. The team also did not have enough cases to look at the risks of women who never smoked versus former smokers versus current smokers. As a result, the study could not determine whether a woman would decrease her risk of developing breast cancer if she stopped smoking. "It's an important question," Sellers says, "and additional research is needed to sort that out."
Last edited by John (Gold) on 29 Jul 2010, 18:15, edited 1 time in total.
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S Sweet
Joined: 18 Dec 2008, 23:59

11 May 2001, 20:45 #3

thanks for posting this zep
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John (Gold)
Joined: 18 Dec 2008, 23:57

10 Aug 2002, 00:38 #4

John's Note: The above articles were published in May 2001 and this thread was started at that time. Below is a new study review just released in the British Medical Journal dated August 10, 2002

BMJ 2002;325:298 - 10 August, 2002
http://bmj.com/cgi/content/full/325/7359/298/d


News extra Risk of breast cancer increases
with number of years' smoking
Roger Dobson Abergavenny

Women who smoke for many years may increase their risk of developing breast cancer. New research shows that for women who had smoked for 40 years or longer, the risk of breast cancer was 60% higher than that of women who had never smoked.

Among those who smoked 20 cigarettes or more a day for 40 years, the increased risk rose to 83%.

"Our findings suggest that smoking of very long duration and high intensity may be associated with increased risk of breast cancer," said the researchers, who say that few studies have looked at whether risk of breast cancer is associated with long term smoking.

The researchers, from Albert Einstein College of Medicine, Bronx, New York, examined the association between cigarette smoking and incidence of breast cancer in a cohort of women who had smoked for up to 40 years at recruitment in the early 1980s; the women were subsequently followed for an average of 10.6 years (International Journal of Cancer 2002:100:723-8).

The research, using data from almost 90 000 women in the Canadian national breast screening study, found that smoking intensity, smoking duration, years since smoking started, and pack years of cigarette consumption had positive associations with breast cancer risk. But age at which smoking began and years since quitting among former smokers were not clearly associated with risk.

The researchers said that the positive association between smoking and breast cancer risk was driven largely by women who had smoked for 40 years, especially those who had smoked 20 cigarettes a day or more.

The study found that women who had smoked either at least one pack of cigarettes a day for 40 years or at least two packs a day for 20 years were at noticeably higher risk than women who accrued the same number of pack years over a shorter duration.

It adds, "Our findings, with respect to risk in association with duration of smoking years since smoking commencement and years since quitting, suggest that smoking may act primarily as an initiator rather than as a promoter of breast cancer, as has been hypothesised with respect to colorectal cancer."

The researchers say that tobacco smoke contains many potentially harmful substances, including nitrogen oxides, volatile aldehydes, alkenes, and aromatic hydrocarbons, which may act differently and at different stages in the development of breast cancer.

They add, "Since prospective cohort studies that have examined breast cancer incidence in relation to smoking duration of 30-40 years or more are scarce, confirmatory data are needed."
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John (Gold)
Joined: 18 Dec 2008, 23:57

07 Sep 2002, 15:07 #5

Australian scientists link smoking to ovarian cancer
Sydney, Sept 4, 2002 (ANI):

It is a well-know fact that smoking increases ones risk of developing lung cancer. Now, Australian researchers claim to have found a link between smoking and ovarian cancer for the first time.

The study involved more than 1600 women, about half of whom had ovarian cancer.

According to scientists at the Queensland Institute of Medical Research, the findings came as a surprise.

"Because smoking doesnt actually come into contact with the ovaries, as it does with the lung, most researchers thought ... theres not going to be an association. Although its not a very strong link - not nearly as strong as the type of risk that youll find for lung cancer - women who smoke definitely are about twice as likely to get ovarian cancer as women who dont smoke," Dr David Purdie was quoted as saying.

The research also showed that women who had several children and those taking contraceptive pills were less likely to get the cancer because the pill triggered a protective effect similar to pregnancy.
Estd. 2001 © Copyright Navakal,Inc. All rights reserved worldwide.[/size]
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John (Gold)
Joined: 18 Dec 2008, 23:57

04 Oct 2002, 20:12 #6

Smoking Within Five Years of First
Period Linked to Breast Cancer Risks

Another new Canadian breast cancer study was just published in Lancet, a respected UK medical journal and a new thread has been started. It too suggests that further studies are necessary to confirm its finding that in premenopausal women, the risk of breast cancer was substantially elevated in women who had begun smoking within five years of their first period and among women who smoked and had never undergone a full-term pregnancy. This is the link to the new thread -
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John (Gold)
Joined: 18 Dec 2008, 23:57

08 Jan 2004, 00:14 #7

Smoking linked to breast cancer
BBC News World Edition
Wednesday, 7 January, 2004, 00:36 GMT


Scientists have produced hard evidence that smoking increases the risk of breast cancer.
Previous research has produced mixed results - some has Image even suggested smoking may have a protective effect.

But a major study of more than 116,000 women by the California Department of Health Services suggests that smoking does pose a significant threat.

The work, which has been challenged by experts, is published in the Journal of the National Cancer Institute.

It does seem that we can now say with some degree of confidence that breast cancer can be added to the ever growing list of serious diseases that can be caused by smoking.
The rate among women who were current smokers was around 30% higher than among those who had never smoked.
Women who started smoking before the age of 20, and those who started at least five years before their first pregnancy appeared to be most at risk.
Breastfeeding is known to help protect against breast cancer, but it might be that exposure to tobacco smoke may undermine this effect.
Heavy smoking or smoking over a long period of time also increased the risk.
However, there was good news for those who had kicked the habit. The researchers found no evidence of a significantly increased risk among former smokers.
There was also no evidence that passive smoking increased the risk of developing cancer.
More work needed
The researchers said more work was required to investigate why smoking might increase the risk of breast cancer.
It is possible that toxins produced by tobacco smoke are stored in the fatty tissues of the breast.
However, they say: "Exposures to tobacco smoke, if causally related to breast cancer, could offer one of the few available modifiable avenues for preventing this disease."
Tobacco is already well known to cause other cancers, most notably lung cancer, as well as other medical problems such as heart disease.
Amanda Sandford, of the anti-smoking charity Action on Smoking and Health, told BBC News Online that it had been harder to prove a link between smoking and breast cancer, than with other cancers.
But she said: "As this is such a big study it does seem that we can now say with some degree of confidence that breast cancer can be added to the ever growing list of serious diseases that can be caused by smoking.
"No organ in the human body is immune to the effects of tobacco smoke, and so it is plausible that cancer could strike anywhere."
Delyth Morgan, breast cancer charity Breakthrough Breast Cancer, said: "A number of studies have investigated the potential link between smoking and breast cancer with conflicting results and more research is needed to clarify a direct association between the two.
"Irrespective of any potential breast cancer risk, smoking is associated with lung and other cancers as well as heart disease and we would strongly advise all women and men not to smoke."
Copyright BBC 2004
Last edited by John (Gold) on 15 Feb 2009, 19:22, edited 1 time in total.
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John (Gold)
Joined: 18 Dec 2008, 23:57

08 Jan 2004, 00:21 #8

Journal of the National Cancer Institute, Vol. 96, No. 1, 1, January 7, 2004
DOI: 10.1093/jnci/96.1.1
© 2004 Oxford University Press

Press Release
Active Smoking Associated With
Increased Risk of Breast Cancer

Katherine Arnold, News Editor
[url=mailto:jncimedia@oupjournals.org]jncimedia@oupjournals.org[/url]

Active smoking appears to play a larger role in the development of breast cancer than previously thought, according to a study in the January 7 issue of the Journal of the National Cancer Institute.

Tobacco smoke contains a number of human carcinogens, and metabolites of cigarette smoke have been found in the breast fluid of smokers. However, studies examining the association between tobacco smoke and breast cancer risk have yielded inconsistent results. Many studies have not been able to independently assess the contributions of the timing of exposure, age of diagnosis, or genetic susceptibilities to the overall risk of breast cancer. In addition, many of these studies did not consider passive smoking exposures, or exposure to secondhand smoke, among nonsmokers.

Peggy Reynolds, Ph.D., of the California Department of Health Services, and her colleagues examined breast cancer risk among 116,544 women in the California Teachers Study who had reported their smoking status on a survey given to them when they enrolled in the study.

Between 1996 and 2000, 2,005 of the women were diagnosed with invasive breast cancer. The incidence of breast cancer among current smokers was approximately 30% greater than that among women who had never smoked, irrespective of whether they were compared to women who had or had not been exposed to passive smoking. Analysis of subgroups of active smokers revealed increased breast cancer risks among women who started smoking before age 20, who began smoking at least 5 years before their first full-term pregnancy, and who had a longer duration of smoking or who smoked 20 or more cigarettes per day.

Current smoking was associated with increased breast cancer risk in women without a family history of breast cancer but not among women with a family history of the disease. There was no statistically significant increase in breast cancer risk among former smokers, and there was no evidence of an association between passive smoking exposure and breast cancer risk.

"Our results, which suggest that active smoking may be associated with an increased risk of breast cancer, argue for further research that can account for heterogeneity in individual susceptibility," the authors write. "Exposures to tobacco smoke, if causally related to breast cancer, could offer one of the few available modifiable avenues for preventing this disease."

###

Contact: Ken August, California Department of Health Services, 916-440-7660; [url=mailto:kaugust@dhs.ca.gov]kaugust@dhs.ca.gov[/url]
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John (Gold)
Joined: 18 Dec 2008, 23:57

21 Mar 2004, 07:27 #9

Carcinogenic effect of nicotine on normal mammary ductal epithelial cells and the protective role of beta-carotene.
Indian J Pathol Microbiol. 2003 Jan;46(1):24-7.


Mazhari NJ, Mandal AK, Thusoo TK.

Department of Pathology, Maulana Azad Medical College and associated LNJP Hospital, New Delhi.

A number of carcinogens like polycyclic hydrocarbons and aromatic amines have been incriminated to induce mammary carcinomas in vitro and in vivo. Studies have supported an inter-relationship between tobacco consumption and breast cancer. Because nicotine is the major alkaloid present in tobacco this study was conducted to find the direct in vitro effect of nicotine on normal mammary ductal epithelial cells. It was seen in the present work that nicotine causes a statistically significant increase in the proliferative rate and ER (estrogen receptor) expression as compared to the control group. This change was more pronounced with a lower concentration of nicotine (650 microg/ml). Colony efficiency also showed a similar trend. Beta carotene was added in the present work to study its anti oxidant effect on nicotine induced changes. Beta carotene significantly decreased the proliferation rate induced by 650 microg/ml nicotine. It also prevented the cytotoxic effect of higher dose of nicotine, however, it failed to alter significantly the ER expression induced by lower concentration of nicotine though it showed decreasing trend.

PMID: 15027713 [PubMed - in process]
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John (Gold)
Joined: 18 Dec 2008, 23:57

04 Mar 2005, 20:28 #10

Smoking Ups Risk of
Premenopausal Breast Cancer
Wed Mar 2, 2005 01:25 PM ET
NEW YORK (Reuters Health) - Both active and "passive" smoking (exposure to secondhand smoke) increase the risk of breast cancer in premenopausal but not postmenopausal women, a study of middle-aged Japanese women suggests.
The investigators think that higher levels of estrogens present in the body of premenopausal women may act jointly with external cancer-causing agents, such as tobacco, to fuel the development of breast cancer.

In the study, Dr. Tomoyuki Hanaoka from the National Cancer Center in Tokyo, Japan, and colleagues studied associations between smoking and breast cancer in close to 22,000 women who were between the ages of 40 and 59 years in 1990.

A total of 180 women developed breast cancer by the end of 1999, they report in the International Journal of Cancer this month.

Among all of the women, 5.7 percent were current smokers, 1.7 percent were ex-smokers, and 92.6 percent had never been active smokers. Sixty-nine percent of these "never-active smokers" reported that they had been exposed to sidestream smoke.

Compared with never-active smokers with no exposure to secondhand smoke, ever-smokers who had yet to enter menopause had a greater than 3-fold elevated risk of developing breast cancer. The elevated risk of developing breast cancer among ever-smokers was not observed in postmenopausal women.

Premenopausal but not postmenopausal women who had never smoked but had been exposed to secondhand smoke had a 2.6-fold increased risk of developing breast cancer.

These results, the authors conclude, show that both active and passive smoking increases the risk of breast cancer in premenopausal women. "Both active and passive smoking are promising targets in the prevention of breast cancer," they write.


SOURCE: International Journal of Cancer March 10, 2005.
© Reuters 2005. All Rights Reserved.
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