Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada.
Cancer Epidemiol Biomarkers Prev. 2011 Oct;20(10):2160-7. doi: 10.1158/1055-9965.EPI-11-0459. Epub 2011 Jul 29.
Indigenous populations in Canada and abroad have poorer survival after a breast cancer diagnosis compared with their geographic counterparts; however, the influence of many demographic, personal, tumor, and treatment factors has not been examined to describe this disparity according to stage at diagnosis.
A case-case design was employed to compare First Nations (FN) women (n = 287) to a frequency-matched random sample of non-FN women (n = 671) diagnosed with breast cancer within the Ontario Cancer Registry. Women were matched on period of diagnosis (1995-1999 and 2000-2004), age at diagnosis (<50 vs. ≥50), and Regional Cancer Centre (RCC). Stage and other factors were collected from medical charts at the RCCs. Survival was compared using an adjusted Cox proportional hazards model and stratified by stage at diagnosis (I, II, and III-IV). Determinants of survival in FN women stratified by stage at diagnosis were also modeled.
Survival was more than three times poorer for FN women diagnosed at stage I than for non-FN women (HR = 3.10, 95% CI = 1.39-6.88). The risk of death after a stage I breast cancer diagnosis was about five times higher among FN women with a comorbidity other than diabetes (HR = 4.65, 95% CI = 1.39-15.53) and was more than five times greater for women with diabetes (HR = 5.49, 95% CI = 1.69-17.90) than for those without a comorbidity.
Having a preexisting comorbidity was the most important factor in explaining the observed survival disparity among FN women.
Improving the general health status of FN women could increase their survival after an early-stage breast cancer diagnosis.
与地理对照人群相比，加拿大和国外的原住民在乳腺癌诊断后生存率较差；然而，尚未根据诊断时的分期来检查许多人口统计学、个人、肿瘤和治疗因素的影响，以描述这种差异。
采用病例对照设计，将安大略癌症登记处诊断为乳腺癌的第一民族（FN）妇女（n = 287）与频率匹配的非 FN 妇女（n = 671）随机对照病例进行比较。按诊断期（1995-1999 年和 2000-2004 年）、诊断时的年龄（<50 岁与≥50 岁）和区域癌症中心（RCC）对妇女进行匹配。从 RCC 的病历中收集分期和其他因素。使用调整后的 Cox 比例风险模型并按诊断时的分期（I、II 和 III-IV）进行分层比较生存情况。还按诊断时的分期对 FN 妇女的生存情况进行建模，确定生存的决定因素。
与非 FN 妇女相比，FN 妇女在 I 期诊断的生存率低三倍以上（HR = 3.10，95%CI = 1.39-6.88）。患有糖尿病以外的合并症的 FN 妇女在 I 期乳腺癌诊断后死亡的风险高约五倍（HR = 4.65，95%CI = 1.39-15.53），而患有糖尿病的妇女（HR = 5.49，95%CI = 1.69-17.90）比没有合并症的妇女高五倍以上。
患有预先存在的合并症是解释 FN 妇女观察到的生存差异的最重要因素。
改善 FN 妇女的一般健康状况可能会提高她们在早期乳腺癌诊断后的生存率。
