一項有關(guān)乳腺癌的研究發(fā)現(xiàn),，女性如果選擇吸煙，患乳腺癌風(fēng)險更大。
這項研究為期10年,，對象為大約8萬名美國女性,，年齡50歲至79歲之間。成果報告3月2日刊登于《英國醫(yī)學(xué)雜志》（BMJ）網(wǎng)站,。
與不吸煙女性相比,，仍吸煙或已戒煙的絕經(jīng)期女性患乳腺癌幾率較普通女性高16%。
另外,，吸大量“二手煙”同樣會增加患乳腺癌風(fēng)險,。
相反，《英國醫(yī)學(xué)雜志》刊登另一份報告顯示,，如果選擇積極生活方式,，適度鍛煉，保持體重,，可使長腸息肉幾率下降,，進(jìn)而降低患腸道癌的風(fēng)險。
“我們已知積極生活方式有助于抵抗腸癌……這次研究發(fā)現(xiàn)（長）腸息肉（幾率）降低最可能解釋這一現(xiàn)象,，”華盛頓大學(xué)醫(yī)學(xué)院研究人員凱瑟琳·沃林說,，“鍛煉有不少好處，包括促進(jìn)免疫系統(tǒng),，緩解肝臟炎癥,，降低胰島素水平。所有這些因素都可能影響長腸息肉的風(fēng)險,。”
《英國醫(yī)學(xué)雜志》發(fā)行方英國癌癥研究會說,，每天“適度”鍛煉半小時和保持合理體重是降低患腸癌風(fēng)險的關(guān)鍵。
英國癌癥研究會以使肌體處于輕度無氧狀態(tài)定義“適度”鍛煉,。（生物谷Bioon.com）
生物谷推薦原文出處：
BMJ 2011; 342:d1016 doi: 10.1136/bmj.d1016
Association of active and passive smoking with risk of breast cancer among postmenopausal women: a prospective cohort study
Juhua Luo, assistant professor1, Karen L Margolis, senior clinical investigator2, Jean Wactawski-Wende, professor and associate chair3, Kimberly Horn, associate professor1, associate center director4, Catherine Messina, research associate professor 5, Marcia L Stefanick, professor6, Hilary A Tindle, assistant professor of medicine7, Elisa Tong, assistant professor8, Thomas E Rohan, professor9
Abstract
Objective To examine the association between smoking and risk of invasive breast cancer using quantitative measures of lifetime passive and active smoking exposure among postmenopausal women.
Design Prospective cohort study.
Setting 40 clinical centres in the United States.
Participants 79?990 women aged 50–79 enrolled in the Women’s Health Initiative Observational Study during 1993–8.
Main outcome measures Self reported active and passive smoking, pathologically confirmed invasive breast cancer.
Results In total, 3520 incident cases of invasive breast cancer were identified during an average of 10.3 years of follow-up. Compared with women who had never smoked, breast cancer risk was elevated by 9% among former smokers (hazard ratio 1.09 (95% CI 1.02 to 1.17)) and by 16% among current smokers (hazard ratio 1.16 (1.00 to 1.34)). Significantly higher breast cancer risk was observed in active smokers with high intensity and duration of smoking, as well as with initiation of smoking in the teenage years. The highest breast cancer risk was found among women who had smoked for ≥50 years or more (hazard ratio 1.35 (1.03 to1.77) compared with all lifetime non-smokers, hazard ratio 1.45 (1.06 to 1.98) compared with lifetime non-smokers with no exposure to passive smoking). An increased risk of breast cancer persisted for up to 20 years after smoking cessation. Among women who had never smoked, after adjustment for potential confounders, those with the most extensive exposure to passive smoking (≥10 years’ exposure in childhood, ≥20 years’ exposure as an adult at home, and ≥10 years’ exposure as an adult at work) had a 32% excess risk of breast cancer compared with those who had never been exposed to passive smoking (hazard ratio 1.32 (1.04 to 1.67)). However, there was no significant association in the other groups with lower exposure and no clear dose response to cumulative passive smoking exposure.
Conclusions Active smoking was associated with an increase in breast cancer risk among postmenopausal women. There was also a suggestion of an association between passive smoking and increased risk of breast cancer.
