Effect of cigarette smoking on risk of breast cancer – includes editor comment – adapted from the British Medical Journal, June 3, 1995 – Tips from Other Journals
Anne D. Walling
While previous studies have examined the relationship between breast cancer and cigarette smoking, results have been contradictory. Bennicke and colleagues studied the incidence of breast cancer and its relationship to smoking in women referred for mammography.
Mammography was performed in 3,240 women between the ages of 15 and 92 years; 1,828 of the women were smokers and 1,412 were nonsmokers. The principal reasons for mammography were palpable lump and localized breast tenderness. In 125 women, fear of cancer was the reason for referral.
Of 230 cases of breast cancer diagnosed, 127 occurred among women who smoked. The overall prevalence of breast cancer among nonsmokers was 7 percent, but this ranged from 0.7 percent in women aged 30 to 39 to over 50 percent in the 45 women who were over 80 years of age. Among smokers, the prevalence of breast cancer also increased with age, from 2.3 percent in women younger than age 39 to 64.3 percent in the 14 women who were older than age 80. In women who smoked for more than 30 years, the prevalence of breast cancer was 15 percent.
In a logistic regression analysis to accommodate multiple risk factors for breast cancer, only age and history of smoking for at least 30 years were significantly associated with an increased risk of developing breast cancer. Among smokers, the median age of women with cancer was 59 years, compared with 67 years in nonsmokers. This difference was statistically significant.
The authors conclude that the risk of breast cancer is increased among women who have smoked for more than 3() years and that breast cancer is likely to occur at a younger age in women who smoke than in women who do not smoke. (BMJ, iune 3, 1995, vol.310, p.1431.)
EDITOR’S NOTE: Many patients and physicians feel relatively helpless to prevent breast cancer. Current strategies are based on early detection of malignancy by mammography and aggressive treatment of disease at a microscopic stage. This study provides at least one positive strategy, smoking cessation, that could lower the risk of breast cancer. Smoking cessation has potentially major, well-documented reductions in cardiac and pulmonary disease morbidity and mortality. Individual women are, however, motivated by different risks and opportunities to avoid specific diseases. For instance, a woman who may not perceive heart or pulmonary disease as a threat may be motivated to stop smoking if she perceives it will lower her risk of breast cancer.
COPYRIGHT 1995 American Academy of Family Physicians
COPYRIGHT 2004 Gale Group