Division of Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77, Stockholm, Sweden.
Breast Cancer Res. 2012 Jan 6;14(1):R5. doi: 10.1186/bcr3086.
Incidence of breast cancer is increasing around the world and it is still the leading cause of cancer mortality in low- and middle-income countries. We utilized Swedish nationwide registers to study breast cancer incidence and case fatality to disentangle the effect of socioeconomic position (SEP) and immigration from the trends in native Swedes.
A nation-wide cohort of women in Sweden was followed between 1961 and 2007 and incidence rate ratio (IRR) and hazard ratio (HR) with 95% confidence intervals (CIs) were estimated using Poisson and Cox proportional regression models, respectively.
Incidence continued to increase; however, it remained lower among immigrants (IRR = 0.88, 95% CI = 0.86 to 0.90) but not among immigrants' daughters (IRR = 0.97, 95% CI = 0.94 to 1.01) compared to native Swedes. Case fatality decreased over the last decades and was similar in native Swedes and immigrants. However, case fatality was significantly 14% higher if cancer was diagnosed after age 50 and 20% higher if cancer was diagnosed in the most recent years among immigrants compared with native Swedes. Women with the highest SEP had significantly 20% to 30% higher incidence but had 30% to 40% lower case fatality compared with women with the lowest SEP irrespective of country of birth. Age at immigration and duration of residence significantly modified the incidence and case fatality.
Disparities found in case fatality among immigrants by age, duration of residence, age at immigration and country of birth emphasize the importance of targeting interventions on women that are not likely to attend screenings or are not likely to adhere to the therapy suggested by physicians. The lower risk of breast cancer among immigrant women calls for more knowledge about how the lifestyle factors in these women differ from those with high risk, so that preventative measures may be implemented.
乳腺癌的发病率在全球范围内呈上升趋势，在中低收入国家仍是癌症死亡的主要原因。我们利用瑞典全国登记处的数据，研究了乳腺癌的发病率和病死率，以厘清社会经济地位（SEP）和移民对本国瑞典人趋势的影响。
在瑞典，对 1961 年至 2007 年期间的女性进行了全国性的队列研究，使用泊松和 Cox 比例风险回归模型分别估计发病率比值（IRR）和风险比（HR）及其 95%置信区间（CI）。
发病率持续上升；然而，移民的发病率仍然较低（IRR = 0.88，95%CI = 0.86 至 0.90），但移民的女儿（IRR = 0.97，95%CI = 0.94 至 1.01）则不然。与本国瑞典人相比，过去几十年病死率有所下降，在本国瑞典人和移民中相似。然而，如果癌症是在 50 岁以后诊断的，或者如果癌症是在最近几年诊断的，那么移民的病死率比本国瑞典人高 14%，如果癌症是在最近几年诊断的，那么移民的病死率比本国瑞典人高 20%。与社会经济地位最低的女性相比，社会经济地位最高的女性的发病率显著高 20%至 30%，但病死率却低 30%至 40%，无论其出生地如何。移民年龄和居住时间对发病率和病死率有显著影响。
根据年龄、居住时间、移民年龄和出生地，移民病死率的差异强调了针对不太可能接受筛查或不太可能遵循医生建议的治疗方案的妇女开展干预措施的重要性。移民妇女患乳腺癌的风险较低，这需要更多地了解这些妇女的生活方式因素与高危妇女的差异，以便实施预防措施。
