Cluze C, Colonna M, Remontet L, Poncet F, Sellier E, Seigneurin A, Delafosse P, Bossard N
Cancer Registry of Isère, Meylan, France.
Breast Cancer Res Treat. 2009 Sep;117(1):121-9. doi: 10.1007/s10549-008-0222-z. Epub 2008 Oct 18.
To explore the effect of age at diagnosis on relative survival from breast cancer at different cancer stages and grades, using appropriate statistical modeling of time-varying and non-linear effects of that prognostic covariate. Data on 4,791 female invasive breast cancers diagnosed between 1990 and 1997 were obtained from a French cancer registry. The effect of age on relative survival was studied using an approach based on excess rate modeling. Different models testing non-linear and non-proportional effects of age were explored for each grade and each stage. In the whole population, the effect of age was not linear and varied with the time elapsed since diagnosis. When analyzing the different sub-groups according to grade and stage, age did not have a significant effect on relative survival in grade 1 or stage 3 tumors. In grade 2 and stage 4 tumors, the excess mortality rate increased with age, in a linear way. In grade 3 tumors, age was a time-dependent factor: older women had higher excess rates than younger ones during the first year after diagnosis whereas the inverse phenomenon was observed 5 years after diagnosis. Our findings suggest that when taking into account grade and stage, the time-varying impact of young age at diagnosis is limited to grade 3 tumors, without evidence of worst prognosis at 5 years for the youngest women.
为探讨诊断时年龄对不同癌症分期和分级的乳腺癌相对生存率的影响，对该预后协变量的时变和非线性效应进行适当的统计建模。从法国癌症登记处获取了1990年至1997年间确诊的4791例女性浸润性乳腺癌的数据。使用基于超额率建模的方法研究年龄对相对生存率的影响。针对每个分级和每个分期，探索了测试年龄的非线性和非比例效应的不同模型。在总体人群中，年龄的影响并非线性，且随诊断后的时间推移而变化。在根据分级和分期分析不同亚组时，年龄对1级或3期肿瘤的相对生存率没有显著影响。在2级和4期肿瘤中，超额死亡率随年龄呈线性增加。在3级肿瘤中，年龄是一个时间依赖性因素：诊断后的第一年，老年女性的超额率高于年轻女性，而诊断后5年则观察到相反的现象。我们的研究结果表明，考虑到分级和分期时，诊断时年轻的时变影响仅限于3级肿瘤，没有证据表明最年轻女性在5年时预后更差。
