Pathological diagnosis is maybe non-essential for special gastric cancer: Case reports and review

Histopathological results are critical for the diagnosis and surgical decision regarding gastric cancer. How-ever, opposite opinions from radiology and pathology can sometimes affect clinical decisions. The two cases reported in this article were both highly suspected as gastric cancer by clinical manifestations and radiologic findings, although both showed negative results in the first biopsy examination. One was confirmed as gastric cancer by the time of the 6 th biopsy, while the other was still negative even after 8 biopsies. With a definite pathologic result and the agreement of the patient for the latter case, both of them finally received surgery. Postoperative pathological examination revealed find-ings that were the same as Borrmann type Ⅳ gastric cancer. We believed that duplicate biopsies under ra-diologic guidance were necessary for highly suspected gastric cancer cases in the absence of a definite pathol-ogy result, and patients should be under close follow-up. We propose that, if gastric cancer is highly sus-pected when typical radiology changes of widely diffuse gastric parietal lesions suffice to exclude lymphoma and other similar situations, and even in absence of a posi-tive biopsy result, a diagnostic laparotomy under lapa-roscopy and even radical gastrectomy may be reason-ably performed by an experienced gastric cancer center with the agreement of the patient after being decided by a multidisciplinary discussion team.

抗EGFR治疗转移性结直肠癌:耐药机制及潜在对策

作为表皮生长因子受体(EGFR)的高效靶向药物,西妥昔单抗和帕尼单抗常用于转移性结直肠癌(mCRC)患者的临床治疗。尽管这些药物取得良好的疗效,但耐药现象也常伴相随。目前,研究人员已经明确了KRAS、NRAS、BRAF突变以及HER2扩增对上述药物疗效的影响,并提出了相应的对策。但EGFR及其配体的异常,PIK3CA、PTEN、TP53、MET、HER3、IRS2、FGFR1和MAP2K1等基因的突变或扩增,胰岛素生长因子-1(IGF-1)的过表达,Bcl-2介导的细胞凋亡调节蛋白(Bim)的低表达,错配修复基因缺陷(dMMR),以及表观遗传不稳定等因素,也可导致mCRC的耐药。尽管耐药的出现具有遗传或表观遗传的异质性,但上述与此有关的分子改变大都集中在某些关键的信号通路上,如RAS/RAF/MAPK通路和PI3K/Akt/mTOR通路。因此,许多研究开始尝试靶向这些信号以期开发出新的治疗方案。本文中,我们对抗EGFR治疗耐药性的产生机制进行了综述,并提出了临床实践中的潜在对策。