Cancer Registry of Norway, Institute of Population-Based Cancer Research, Norway.
Cancer Registry of Norway, Institute of Population-Based Cancer Research, Norway; Department of Research and Innovation, Møre and Romsdal Hospital Trust, Norway.
Breast. 2018 Apr;38:107-113. doi: 10.1016/j.breast.2017.12.001. Epub 2018 Jan 5.
To describe the association between coding and classification practices and observed stage-specific incidence and survival trends in Norway over time. We identified all women diagnosed with invasive breast cancer in the period between 1980 and 2015. Changes in the coding and classification of breast cancer in the study period were described, and stage-specific incidence rates and relative survival were calculated. A total of 90 362 women were diagnosed with primary breast cancer, stage I-IV, or unknown stage, in the study period. Stage-specific incidence was significantly influenced by changes in coding practice, classification systems and the implementation of the screening program. These changes have mostly affected the proportion of stage I and "unknown", but also stages II, III and IV. The proportion of stage I showed a clear increase during the implementation period of the national screening program, and was most pronounced within the age group 50-69. Stage-specific trends for relative survival were less influenced by changes in coding and classification of stage. Our study showed that the stage-specific incidence trends in Norway were influenced by changes in the coding and classification practice. These findings should be taken into consideration in future research and evaluation related to stage-specific trends and stage migration of breast cancer in Norway.
描述编码和分类实践与挪威随时间推移观察到的特定阶段发病率和生存趋势之间的关联。我们确定了在 1980 年至 2015 年期间诊断出的所有患有浸润性乳腺癌的女性。描述了研究期间乳腺癌编码和分类的变化，并计算了特定阶段的发病率和相对生存率。在研究期间，共有 90362 名女性被诊断患有 I 期-IV 期或未知期的原发性乳腺癌。特定阶段的发病率受到编码实践、分类系统和筛查计划实施变化的显著影响。这些变化主要影响了 I 期和“未知”的比例，但也影响了 II 期、III 期和 IV 期。I 期的比例在全国筛查计划实施期间明显增加，在 50-69 岁年龄组中最为明显。特定阶段相对生存率的趋势受阶段编码和分类变化的影响较小。我们的研究表明，挪威特定阶段发病率趋势受到编码和分类实践变化的影响。在未来与挪威乳腺癌特定阶段趋势和阶段转移相关的研究和评估中，应考虑这些发现。
