Abstract:
Tumor markers are assuming a growing role in all aspects of cancer care, starting from screening to follow-up after treatment, and their judicious application in clinical practice needs a thorough understanding of the basics of pathophysiology, techniques of identification or testing, reasons for out-of-range levels of tumor markers, as well as the knowledge of evidence of their role in any given malignancy. These are, at the most, just an adjunct to diagnosis, and establishing a diagnosis on the basis of tumor markers alone (especially a single result) is fraught with associated pitfalls because of the problem of nonspecificity. In reality an ideal tumor marker does not exist. Detection can be done either in tissue or in body fluids like ascitic or pleural fluid or serum. Clinical uses can be broadly classified into 4 groups: screening and early detection, diagnostic confirmation, prognosis and prediction of therapeutic response and monitoring disease and recurrence. In addition to variable sensitivity and specificity, the prevalence of a particular malignancy may be a major determinant in the application of a particular test as a screening tool. Serum levels, in certain situations, can be used in staging, prognostication or prediction of response to therapy. Monitoring disease is, perhaps, the most common clinical use of serum tumor markers. Rising trend in serum levels may detect recurrence of disease well before any clinical or radiological evidence of disease is apparent (\"biochemical recurrence\"). Sampling should ideally be repeated after 5-6 half-lives of the marker in question (or the marker with the longest half-life if multiple markers are being considered); but if found elevated, the next sampling after 2-4 weeks, for additional evidence, may be justified.
摘要:
肿瘤标志物在癌症治疗的各个方面发挥着越来越重要的作用,从筛查开始到治疗后的随访,他们在临床实践中的明智应用需要对病理生理学的基础知识有透彻的了解,识别或测试技术,肿瘤标志物水平超出范围的原因,以及它们在任何特定恶性肿瘤中作用的证据的知识。这些是,最多,只是诊断的辅助手段,由于非特异性问题,仅根据肿瘤标志物(尤其是单一结果)进行诊断充满了相关的陷阱。实际上,不存在理想的肿瘤标志物。可以在组织或体液如腹水或胸膜液或血清中进行检测。临床应用大致可分为四类:筛查和早期发现,诊断确认,预后和预测治疗反应和监测疾病和复发。除了可变的灵敏度和特异性,特定恶性肿瘤的患病率可能是特定测试作为筛查工具应用的主要决定因素.血清水平,在某些情况下,可用于分期,对治疗反应的预测或预测。监测疾病是,也许,血清肿瘤标志物的临床运用最为普遍。血清水平的上升趋势可以在疾病的任何临床或放射学证据明显之前检测到疾病的复发(“生化复发”)。理想情况下,应在所讨论的标记物(或如果考虑多个标记物,则半衰期最长的标记物)的5-6个半衰期后重复采样;但如果发现升高,2-4周后的下一次采样,为了获得更多证据,可能是合理的。