筛查在三类恶性肿瘤精准预防策略中的意义

Screening strategy on precision prevention strategies for three types of malignant tumors

恶性肿瘤大体可分为快速进展肿瘤、缓慢进展肿瘤和“惰性”肿瘤。快速进展肿瘤(如肝癌、胰腺癌、胆管癌等)发病早、发病到死亡时间短、治疗效果差,这类肿瘤应重点实施1级预防;缓慢进展肿瘤(如肺癌、结直肠癌、乳腺癌、胃癌等)发病较晚、有明确癌前病变、从发病到死亡时间较长、对治疗效果较好,适合于2级预防;“惰性”肿瘤(前列腺癌、甲状腺癌等)不影响人群期望寿命,适合于3级预防。对“惰性”肿瘤开展早期筛查,可能导致过度医疗。对快速进展肿瘤早期筛查难以捕捉到早期癌症,投入产出比低。对于缓慢进展肿瘤,开展肿瘤筛查利大于弊,适合2级预防,但是存在过度诊断问题。针对不同类型肿瘤采用合适的防治策略具有十分重要的意义。目前继续开展大样本队列研究和随访完整的随机对照临床研究,才能准确评估癌症预防和控制的效果。本文围绕恶性肿瘤进展特征与患者预后特征,讨论筛查手段对肿瘤精准预防的意义。

Malignant tumors can be classified into three categories,rapidly progressing tumors,slowly progressing tumors,and"indolent"tumors.Rapidly progressing tumors(such as liver cancer,pancreatic cancer,and cholangiocarcinoma)have acute onset,shorter time duration from onset to death,and poorer treatment effects,which warrants primary prevention.Slowly progressing tumors(such as lung cancer,colorectal cancer,breast cancer,and gastric cancer)have slow onset,clear precancerous lesions,longer time duration from onset to death,and better therapeutic effects,which is accordingly suitable for secondary prevention.“Indolent”tumors(such as prostate and thyroid cancer)do not affect the life expectancy and are suitable for tertiary prevention.Early screening of“indolent”tumors may lead to overtreatment.Furthermore,early screening of rapidly progressing tumors is difficult to identify early cancers,which results in low cost-effectiveness.In contrast,for slowly progressing tumors suitable for secondary prevention,early screening may have cost-effectiveness,though there might be over-diagnosis.It is crucial to adopt appropriate prevention and treatment strategies for diverse types of tumors.Currently,large-scale cohort studies and randomized controlled clinical trials with complete follow-up may accurately evaluate the effect of cancer prevention strategies.This review discusses the significance of screening in precision prevention of tumors based on the characteristics of tumor progression and patients’prognosis.