一项有关乳腺癌的研究发现,女性如果选择吸烟,患乳腺癌风险更大。
这项研究为期10年,对象为大约8万名美国女性,年龄50岁至79岁之间。成果报告3月2日刊登于《英国医学杂志》(BMJ)网站。
与不吸烟女性相比,仍吸烟或已戒烟的绝经期女性患乳腺癌几率较普通女性高16%。
另外,吸大量“二手烟”同样会增加患乳腺癌风险。
相反,《英国医学杂志》刊登另一份报告显示,如果选择积极生活方式,适度锻炼,保持体重,可使长肠息肉几率下降,进而降低患肠道癌的风险。
“我们已知积极生活方式有助于抵抗肠癌……这次研究发现(长)肠息肉(几率)降低最可能解释这一现象,”华盛顿大学医学院研究人员凯瑟琳·沃林说,“锻炼有不少好处,包括促进免疫系统,缓解肝脏炎症,降低胰岛素水平。所有这些因素都可能影响长肠息肉的风险。”
《英国医学杂志》发行方英国癌症研究会说,每天“适度”锻炼半小时和保持合理体重是降低患肠癌风险的关键。
英国癌症研究会以使肌体处于轻度无氧状态定义“适度”锻炼。(生物谷Bioon.com)
生物谷推荐原文出处:
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.