Van Dijck J A, Verbeek A L, Beex L V, Hendriks J H, Holland R, Mravunac M, Straatman H, Werre J M
National Expert and Training Centre for Breast Cancer Screening in the Netherlands, Nijmegen.
Int J Cancer. 1997 Jan 17;70(2):164-8. doi: 10.1002/(sici)1097-0215(19970117)70:2<164::aid-ijc5>3.0.co;2-v.
Recent case-referent studies in the Nijmegen breast-screening programme have shown a reduction in breast-cancer mortality of approximately 50% due to screening of women aged 65 years and older. In this type of study, however, the results may be biased because of self-selection. The purpose of our present study was to compare the breast-cancer mortality rate in a population invited for screening with that of a reference population from an area without a screening programme. In 1977-1978, 6773 women aged 68-83 years were enrolled in the mammographic screening programme in Nijmegen, The Netherlands. The women were followed up until 31 December, 1990. The reference population consisted of women from the same birth cohort from Arnhem, a neighbouring city without mass screening, for whom the entry date was 1 January, 1978. The ratios of the Nijmegen and Arnhem breast-cancer mortality rates with 95% confidence intervals (CI) were calculated. In the study period, 173 patients were diagnosed with primary breast cancer in Nijmegen vs. 183 in Arnhem; 40 Nijmegen patients had died of breast cancer vs. 51 Arnhem patients. The cumulative mortality-rate ratio was 0.80 (95% CI = 0.53-1.22). In the periods 1978-1981, 1982-1985 and 1986-1990, the mortality rate ratios were 1.44 (95% CI = 0.67-3.10), 081 (95% CI = 0.37-1.79) and 0.53 (95% CI = 0.27-1.04), respectively. After adjustment for the difference in incidence rate that existed between the Nijmegen and Arnhem populations, mammographic screening of women older than 65 can be expected to yield a 40% reduction in breast-cancer mortality after 10 years.
奈梅亨乳腺癌筛查项目最近的病例对照研究表明，对65岁及以上女性进行筛查可使乳腺癌死亡率降低约50%。然而，在这类研究中，结果可能因自我选择而产生偏差。我们当前研究的目的是比较受邀参加筛查人群的乳腺癌死亡率与来自未开展筛查项目地区的对照人群的乳腺癌死亡率。1977年至1978年，荷兰奈梅亨有6773名年龄在68至83岁之间的女性参加了乳房X线筛查项目。这些女性一直被随访至1990年12月31日。对照人群由来自阿纳姆同一出生队列的女性组成，阿纳姆是邻近城市，未开展大规模筛查，其进入研究的日期为1978年1月1日。计算了奈梅亨和阿纳姆乳腺癌死亡率的比值及95%置信区间（CI）。在研究期间，奈梅亨有173例患者被诊断为原发性乳腺癌，阿纳姆有183例；奈梅亨有40例患者死于乳腺癌，阿纳姆有51例。累积死亡率比值为0.80（95%CI = 0.53 - 1.22）。在1978年至1981年、1982年至1985年和1986年至1990年期间，死亡率比值分别为1.44（95%CI = 0.67 - 3.10）、0.81（95%CI = 0.37 - 1.79）和0.53（95%CI = 0.27 - 1.04）。在对奈梅亨和阿纳姆人群之间存在的发病率差异进行调整后，预计对65岁以上女性进行乳房X线筛查10年后可使乳腺癌死亡率降低40%。
