Hofvind Solveig, Bjurstam Nils, Sørum Ragnhild, Bjørndal Hilde, Thoresen Steinar, Skaane Per
The Cancer Registry of Norway, Norway.
J Med Screen. 2006;13(4):192-6. doi: 10.1177/096914130601300406.
To describe the distribution and prognostic tumour characteristics of interval breast cancers diagnosed in four periods after index screen (1-6, 7-12, 13-18 and 19+ months) in a population-based screening programme inviting women aged 50-69 years to biennial screening.
The Norwegian Breast Cancer Screening Programme (NBCSP) Methods: In all, 848 interval breast cancer cases were diagnosed in 437,235 screening examinations. The distribution and prognostic tumour characteristics of the interval cancers diagnosed in four periods in the screening interval will be described. Proportions and rates will be compared by chi(2)-test.
A total of 70% of the interval cancers in the NBCSP were diagnosed in the second year of the interval. Except for tumour size (P = 0.027), we found no evidence of adverse prognostic breast characteristics (grade, lymph node involvement, oestrogen and progesterone receptor positive) in invasive tumours diagnosed during the second versus the first year of the screening interval (Chi square P > 0.05 for all). The prognostic characteristics of the tumours did not differ by age groups. It was a decreasing interval cancer rate per 10,000 women-years by age.
The risk of interval cancer increases by time after index screen, and 70% of the interval cancers in the NBCSP were diagnosed in the second year of the interval. Prognostic histological tumour characteristics did not differ by time after index screen, thus mean sojourn time (tumour growth rate) seems important for stating an optimal screening interval in a population-based screening programme.
描述在一项针对50 - 69岁女性的两年一次筛查的人群筛查项目中，初次筛查后四个时间段（1 - 6个月、7 - 12个月、13 - 18个月和19个月以上）诊断出的间期乳腺癌的分布及预后肿瘤特征。
挪威乳腺癌筛查项目（NBCSP）
在437,235次筛查检查中，共诊断出848例间期乳腺癌病例。将描述在筛查间期四个时间段诊断出的间期癌的分布及预后肿瘤特征。比例和发生率将通过卡方检验进行比较。
NBCSP中70%的间期癌在间期的第二年被诊断出。除肿瘤大小外（P = 0.027），在筛查间期第二年与第一年诊断出的浸润性肿瘤中，我们未发现不良预后乳腺特征（分级、淋巴结受累情况、雌激素和孕激素受体阳性）的证据（所有卡方检验P > 0.05）。肿瘤的预后特征在不同年龄组之间无差异。按年龄计算，每10,000妇女年的间期癌发生率呈下降趋势。
间期癌的风险随初次筛查后的时间增加，NBCSP中70%的间期癌在间期的第二年被诊断出。预后组织学肿瘤特征在初次筛查后的时间上无差异，因此平均停留时间（肿瘤生长速率）对于在人群筛查项目中确定最佳筛查间期似乎很重要。
