Active Smoking Linked To Increased Risk Of Breast Cancer

Non-Smokers Exposed To Smoke Were Not At A Higher Risk

Active smoking appears to play a larger role in the development of breast cancer than previously thought, according to a study reported in 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, experts say.

The authors of the new study say that 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.

Dr. Peggy Reynolds 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, the authors report.

Analysis of subgroups of active smokers revealed increased breast cancer risks among women who started smoking before age 20; who began smoking at least five 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 a link between passive smoking exposure and breast cancer risk.

Always consult your physician for more information.

Risk Factors for Breast Cancer

Any woman may develop breast cancer. However, the following risk factors may increase the likelihood of developing the disease.

Risk factors that cannot be changed:

• gender
  Breast cancer occurs nearly 100 times more often in women than in men.

• aging
  A majority of cases occur after age 50.

• personal history of breast cancer

• previous breast irradiation

• family history and genetic factors
  Having a close relative, such as a mother or sister, with breast cancer increases the risk. This includes changes in certain genes such as BRCA1, BRCA2, and others.

• benign breast disease

• previous breast biopsy in which the tissue showed atypical hyperplasia

• menstrual periods that began early in life

• menopause began later in life

The most frequently cited lifestyle-related risk factors:

• smoking

• not having children, or first child after age 35

• oral contraceptives

• obesity and a high-fat diet

• physical inactivity

• alcohol

• long-term, post-menopausal use of combined estrogen and progestin (HRT)

• weight gain and obesity after menopause

Environmental risk factors:

• Exposure to pesticides, or other chemicals, is currently being examined as a possible risk factor.

Always consult your physician for more information.

Online Resources

(Our Organization is not responsible for the content of Internet sites.)   

American Cancer Society

American Society for Clinical Oncology

Centers for Disease Control and Prevention (CDC)

National Institutes of Health (NIH)

National Women's Health Information Center 

February 2004

Risk Factors for Breast Cancer

Tailoring Adjuvant Therapy for Early-stage Breast Cancer Studied

Online Resources

Tailoring Adjuvant Therapy for Early-stage Breast Cancer Studied

Although chemotherapy and ovarian function suppression are both effective adjuvant therapies for patients with early-stage breast cancer, little is known of the efficacy of their sequential combination (how well the treatment works when given in a certain order), state researchers in a new study report.

Adjuvant therapy is a term used to describe when physicians choose more than one therapy in treating a patient, specifically the therapy is given after the primary cancer treatment is completed in order to improve the chance of a cure.

A new study by the International Breast Cancer Study Group (IBCSG)  concludes that premenopausal women with lymph node-negative breast cancer should receive adjuvant therapy tailored according to the estrogen receptor status of the primary tumor.

The study was reported in the Journal of the National Cancer Institute (JNCI).

Patients with estrogen receptor (ER)-negative, or endocrine nonresponsive, breast cancer should receive adjuvant chemotherapy, according to the study, whereas for patients with ER-positive, or endocrine responsive, tumors, the use of endocrine therapy alone or in combination with adjuvant chemotherapy requires further study.

Some studies have suggested that cytotoxic chemotherapy benefits premenopausal women with breast cancer because it causes premature menopause.

The new study addresses whether adjuvant ovarian function suppression can be used as a replacement for or as a supplement to cytotoxic adjuvant chemotherapy for premenopausal women with early-stage breast cancer.

In an editorial commenting of this study in the JNCI, the authors said, "These findings support the idea that ovarian suppression "is a viable treatment alternative for at least some premenopausal women with breast cancer." The authors, Dr. Joseph L. Pater and Dr. Wendy R. Parulekar, are physicians at the National Cancer Institute of Canada Clinical Trials Group at Queen's University in Kingston, Ontario.

In the study, Dr. Monica Castiglione-Gertsch, a member of the IBCSG, compared outcomes of 1,063 pre- and perimenopausal women who were previously treated for lymph-node negative (early-stage) breast cancer and randomly assigned to receive adjuvant chemotherapy, adjuvant therapy with the ovarian function suppression drug goserelin, or adjuvant chemotherapy followed by goserelin.

The women were tested to determine the estrogen receptor status of their tumors.

After a median follow-up of seven years, there was no difference in disease-free survival or overall survival among patients in the three treatment groups.

However, a subgroup analysis showed that patients with ER-negative tumors who received chemotherapy alone or followed by goserelin had better disease-free survival than patients who received goserelin alone.

By contrast, among patients with ER-positive tumors, results were similar after chemotherapy alone or goserelin alone. Sequential use of chemotherapy followed by goserelin resulted in a statistically nonsignificant benefit that was limited to younger women.

The study authors caution that the study findings "should not alter current patient care, but rather emphasize the relevance of current studies of chemotherapy and endocrine agents."

Drs. Pater and Parulekar agree, recommending that future studies examine the selective use of ovarian suppression in women who are not rendered menopausal by chemotherapy.

Always consult your physician for more information.