乳腺癌發(fā)病率在不同族群間存在差異，歐美國家白人女性患病風(fēng)險整體高于亞洲及非洲女性。不過英國一項大規(guī)模研究顯示，這種差異在很大程度上源自生活方式，遺傳因素并非主因。
英國牛津大學(xué)等機(jī)構(gòu)研究人員在新一期《英國癌癥雜志》上報告說，他們對英格蘭地區(qū)超過100萬名年齡在50至64歲之間的女性進(jìn)行了健康調(diào)查，其中有近6000名南亞裔女性和近5000名非洲裔女性，研究人員通過調(diào)查問卷、查閱醫(yī)療記錄等方式對她們的生活習(xí)慣、新生兒喂養(yǎng)方式及乳腺癌患病情況進(jìn)行了分析。
結(jié)果發(fā)現(xiàn)，白人女性患乳腺癌的幾率最高，與之相比，南亞裔女性的患病幾率要低18％，非洲裔女性的患病幾率要低15％。進(jìn)一步分析顯示，在影響患病風(fēng)險的因素中，生活方式所占比重遠(yuǎn)大于基因差異。
具體來看，白人女性中僅有23％報告說不飲酒，而南亞裔和非洲裔女性有75％和38％不飲酒；白人女性的母乳喂養(yǎng)率不足七成，而另外兩者這一比例均超過八成；白人女性使用激素替代療法緩解更年期綜合征的比例也更高。如果在計算中去除這些風(fēng)險因素的影響，不同族群女性患乳腺癌的風(fēng)險則相差不多。
研究人員說，這項研究說明，乳腺癌患病風(fēng)險在“很大程度上”與生活方式密切相關(guān)，這再次提醒女性堅持健康生活方式對于降低乳腺癌風(fēng)險的重要性，比如應(yīng)注意膳食平衡、減少飲酒、適量運(yùn)動和控制體重等。
Ethnic differences in breast cancer incidence in England are due to differences in known risk factors for the disease: prospective study
background: In the United Kingdom, breast cancer incidence is lower in South Asian and Black women than in White women, but the extent to which this is due to known risk factors is unknown. In a large prospective study, we describe breast cancer incidence by ethnicity, before and after adjustment for known risk factors for the disease.
methods: Women were recruited into the Million Women Study in 1996–2001, when information on reproductive and lifestyle factors known to influence the risk of breast cancer was obtained. Ethnicity was determined from study questionnaires and hospital admission data. Cox regression models were used to calculate adjusted relative risks (RR) for incident breast cancer in South Asians and Blacks compared with Whites.
results: Analyses included 5877 South Asian, 4919 Black, and 1 038 144 White women in England. The prevalence of 8 out of the 9 risk factors for breast cancer examined, differed substantially by ethnicity (P<0.001 for each), such that South Asian and Black women were at a lower risk of the disease than White women. During 12.2 years of follow-up incident breast cancer occurred in 217 South Asians, 180 Blacks, and 45 191 Whites. As expected, breast cancer incidence was lower in South Asians (RR=0.82, 95% CI 0.72–0.94) and Blacks (RR=0.85, 0.73–0.98) than in Whites when the analyses were adjusted only for age and region of residence. However, after additional adjustment for the known risk factors for the disease, breast cancer incidence was similar to that of Whites, both in South Asians (0.95, 0.83–1.09) and in Blacks (0.91, 0.78–1.05).
conclusion: South Asian and Black women in England have lower incidence rates of breast cancer than White women, but this is largely, if not wholly, because of differences in known risk factors for the disease.
Keywords: breast cancer incidence; ethnicity; breast cancer risk factors
