Whittemore A S, Kolonel L N, Wu A H, John E M, Gallagher R P, Howe G R, Burch J D, Hankin J, Dreon D M, West D W
Department of Health Research and Policy, Stanford University School of Medicine, Calif. 94305-5092, USA.
J Natl Cancer Inst. 1995 May 3;87(9):652-61. doi: 10.1093/jnci/87.9.652.
International and interethnic differences in prostate cancer incidence suggest an environmental, potentially modifiable etiology for the disease.
We conducted a population-based case-control study of prostate cancer among blacks (very high risk), whites (high risk), and Asian-Americans (low risk) in Los Angeles, San Francisco, Hawaii, Vancouver, and Toronto. Our aim was to evaluate the roles of diet, physical activity patterns, body size, and migration characteristics on risk in these ethnic groups and to assess how much of the interethnic differences in risk might be attributed to interethnic differences in such lifestyle characteristics.
We used a common protocol and questionnaire to administer personal interviews to 1655 black, white, Chinese-American, and Japanese-American case patients diagnosed during 1987-1991 with histologically confirmed prostate carcinoma and to 1645 population-based control subjects matched to case patients by age, ethnicity, and region of residence. Sera collected from 1127 control subjects were analyzed for levels of prostate-specific antigen (PSA) to permit comparison of case patients with control subjects lacking serological evidence of prostate disease. Odds ratios were estimated using conditional logistic regression. We estimated the proportion of prostate cancer attributable to certain risk factors and the proportion of interethnic risk differences attributable to interethnic differences in risk-factor prevalence.
A positive statistically significant association of prostate cancer risk and total fat intake was found for all ethnic groups combined. This association was attributable to energy from saturated fats; after adjusting for saturated fat, risk was associated only weakly with monounsaturated fat and was unrelated to protein, carbohydrate, polyunsaturated fat, and total food energy. Saturated fat intake was associated with higher risks for Asian-Americans than for blacks and whites. In all ethnic groups combined, the risk tended to be higher when only case patients with advanced disease were compared with control subjects with normal PSA levels. Among foreign-born Asian-Americans, risk increased independently with years of residence in North America and with saturated fat intake. Crude estimates suggest that differences in saturated fat intake account for about 10% of black-white differences and about 15% of white-Asian-American differences in prostate cancer incidence. Risk was not consistently associated with intake of any micronutrients, body mass, or physical activity patterns.
These data support a causal role in prostate cancer for saturated fat intake but suggest that other factors are largely responsible for interethnic differences in risk.
前列腺癌发病率的国际及种族间差异表明该疾病存在环境性病因，且这种病因可能是可以改变的。
我们在洛杉矶、旧金山、夏威夷、温哥华和多伦多开展了一项基于人群的前列腺癌病例对照研究，研究对象包括黑人（高危）、白人（高危）和亚裔美国人（低危）。我们的目的是评估饮食、身体活动模式、体型和移民特征在这些种族群体的患病风险中所起的作用，并评估种族间患病风险差异中有多少可归因于这些生活方式特征的种族间差异。
我们采用通用方案和问卷，对1987年至1991年期间确诊为组织学确诊前列腺癌的1655名黑人、白人、华裔美国人和日裔美国人病例患者以及1645名按年龄、种族和居住地区与病例患者匹配的基于人群的对照对象进行了个人访谈。对从1127名对照对象采集的血清进行前列腺特异性抗原（PSA）水平分析，以便将病例患者与缺乏前列腺疾病血清学证据的对照对象进行比较。使用条件逻辑回归估计比值比。我们估计了归因于某些危险因素的前列腺癌比例以及归因于危险因素患病率种族间差异的种族间风险差异比例。
所有种族群体综合起来，前列腺癌风险与总脂肪摄入量之间存在统计学上显著的正相关。这种关联归因于饱和脂肪提供的能量；在调整饱和脂肪后，风险仅与单不饱和脂肪有微弱关联，与蛋白质、碳水化合物、多不饱和脂肪和总食物能量无关。亚裔美国人的饱和脂肪摄入量与较高风险相关，高于黑人和白人。在所有种族群体综合起来的情况下，仅将晚期疾病病例患者与PSA水平正常的对照对象进行比较时，风险往往更高。在外国出生的亚裔美国人中，风险随着在北美居住年限和饱和脂肪摄入量的增加而独立增加。粗略估计表明，饱和脂肪摄入量差异约占前列腺癌发病率黑人与白人差异的10%以及白人与亚裔美国人差异的15%。风险与任何微量营养素的摄入量、体重或身体活动模式均无一致关联。
这些数据支持饱和脂肪摄入量在前列腺癌中起因果作用，但表明其他因素在很大程度上导致了种族间的风险差异。
