Over the past 30 years, awareness and screening have led to an emphasis on early diagnosis of cancer. Although the goals of these efforts were to reduce the rate of late-stage disease and decrease cancer mortality, secular trends and clinical trials suggest that these goals have not been met; national data demonstrate significant increases in early-stage disease, without a proportional decline in later-stage disease. What has emerged has been an appreciation of the complexity of the pathologic condition called cancer. The word “cancer” often invokes the specter of an inexorably lethal process; however, cancers are heterogeneous and can follow multiple paths, not all of which progress to metastases and death, and include indolent disease that causes no harm during the patient’s lifetime. Better biology alone can explain better outcomes. Although this complexity complicates the goal of early diagnosis, its recognition provides an opportunity to adapt cancer screening with a focus on identifying and treating those conditions most likely associated with morbidity and mortality.
在过去30年中，（对癌症的）认知和筛查唤起了人们对癌症早期诊断的重视。虽然这些努力的目的是为降低晚期疾病比率并降低癌症死亡率，但长期趋势和临床试验均表明这些目标都没有达到; 国家数据显示在晚期疾病无下降趋势的同时，早期疾病显著攀升。这些已显现的现象是对称为癌症的病理状态复杂性的评估。“癌症”这一词汇常会唤起我们对这一无法避免的致命过程的恐怖阴影; 然而，癌症具有多样性并有多种多样的发展，并不是所有癌症都会最终导致转移和死亡，比如包括对患者终生都不会造成伤害的惰性疾病。更好的生物学本身能解释更好的结果。虽然这种复杂性使得早期诊断的目标复杂化，但对它的认知为适应重在识别和治疗这些与发病率和死亡率最紧密相关情况的癌症筛查提供了条件。