Using high-quality population data with 24 years of follow-up from the gradually introduced BreastScreen Norway program, we studied whether all breast carcinomas detected at mammography screening 50-69 years of age would progress to clinical symptoms within 85 years of age. First, we estimated the incidence rates of breast carcinomas by age in scenarios with or without screening, based on an extended age-period-cohort incidence model. Next, we estimated the frequency of non-progressive tumors among screening-detected cases, by calculating the difference in the cumulative rate of breast carcinomas between the screening and non-screening scenarios at 85 years of age.
Among women who attended BreastScreen Norway from the age of 50 to 69 years, we estimated that 1.1% of the participants were diagnosed with a breast carcinoma without the potential to progress to symptomatic disease by 85 years of age. This proportion of potentially non-progressive tumors corresponded to 15.7% [95% CI 3.3, 27.1] of breast carcinomas detected at screening.
Our findings suggest that nearly one in six breast carcinomas detected at screening may be non-progressive.
方法:使用高质量的人口数据,并从逐步引入的BreastScreen挪威计划进行了24年的随访,我们研究了在50-69岁的乳房X线摄影筛查中发现的所有乳腺癌是否会在85岁内发展为临床症状.首先,我们估计了在有或没有筛查的情况下,乳腺癌的发病率按年龄划分,基于延长的年龄-时间段-队列发病率模型。接下来,我们估计了筛查检测到的病例中非进展性肿瘤的频率,通过计算85岁时筛查和非筛查方案之间的乳腺癌累积率差异。
结果:在50至69岁参加BreastScreen挪威的女性中,我们估计,1.1%的参与者在85岁时被诊断出患有乳腺癌,但没有可能进展为有症状的疾病.潜在非进展性肿瘤的这一比例相当于筛查时检测到的乳腺癌的15.7%[95%CI3.3,27.1]。
结论:我们的研究结果表明,在筛查中发现的乳腺癌中,六分之一可能是非进行性的。