Colorectal serrated pathway cancers and precursors

The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction.     

扶正消瘤颗粒对原发性肝癌血清中VEGF、HIF-1α表达的影响及临床意义＊

目的 探讨扶正消瘤颗粒对原发性肝癌血清中血管内皮生长因子（Vascular endothelial growth factor，VEGF）和缺氧诱导因子-1α（Hypoxia inducible factor-1α，HIF-1α）表达的影响及临床意义。方法 选择符合纳入标准的原发性肝癌患者66例，按1∶1随机分试验组和对照组。观察治疗过程中两组VEGF、HIF-1α水平的变化及对患者临床疗效指标的影响。结果 （1）在性别、年龄、合并乙型肝炎、Child-Pugh分级、AFP值、临床分期方面，试验组和对照组差异无统计学意义（P > 0.05）。（2）肝癌患者在治疗各时间节点的VEGF和HIF-1α表达水平呈线性正相关（r = 0.829，P < 0.001）。（3）VEGF浓度在经导管动脉化疗栓塞术（Transcatheter arterial chemoembolization，TACE）后3月降至术前水平（P > 0.05），HIF-1α在TACE后3月仍高于术前（P < 0.05）。（4）扶正消瘤颗粒可降低HIF-1α水平，下调VEGF的表达。（5）扶正消瘤颗粒可减少TACE序贯RFA治疗后的不良反应，提高患者的生活质量（P < 0.05）。（6）血清中VEGF水平与生活质量无明显相关性（P > 0.05，r = 0.251），HIF-1α水平与生活质量存在正相关性（P < 0.05，r = 0.450）。结论 扶正消瘤颗粒可明显改善TACE序贯RFA治疗后患者生活质量，降低HIF-1α水平，下调VEGF的表达，抑制肿瘤血管生成。