TORONTO – Breast-cancer screening has long been viewed as one of the most important tools for reducing mortality from the disease. That is why recent doubts about its effectiveness – intensified by the publication in February of the 25-year follow-up to the Canadian National Breast Screening Study – have come as such a shock.
多伦多——乳腺癌筛查一向被看作降低该疾病死亡率的最重要的工具之一。因此，不久前公布的对其有效性的质疑令人震惊——同样令人震惊的还有去年2月发表的加拿大国家乳腺筛查研究25年随访记录。乳腺癌筛查这样有利于疾病早期发现的手段怎么可能没有降低死亡率？