胃癌介绍精品课件.ppt

* * * * * 胃癌介绍 * 胃癌好发部位：胃窦、胃小弯、贲门、胃大弯 一、胃的解剖和生理 * 居全球所有癌症死亡率的第二位 居我国各种消化道恶性肿瘤的首位 居全身肿瘤的第三位 男∶女 = 2∶1 二、胃癌的流行病学 * 胃癌的发病率和死亡率在不同国家、地区相差很大。（东亚、东欧、南美为高发地域；北非和西非发病率最低） 我国各省、市、自治区胃癌的发病率和死亡率分布也不平衡。（以西北地区和东南沿海发病率较高；而广东、广西、贵州为低发区） 在同一省市内其发病率也不平衡 年龄：50岁 二、胃癌的流行病学 * 胃癌的病因尚未完全清楚，但已经知的许多因素均可以增加胃黏膜上皮细胞癌变发生的机会。 1. 2. 3. 4. 地域环境及饮食生活习惯 幽门螺杆菌感染 癌前病变 遗传因素 其他相关因素，如性别、年龄、血型等。 三、胃癌的病因 * 地域环境及饮食生活习惯 1. 胃癌的发病有明显的地域差别 长期食用熏、烤、腌制食物、高盐食物和盐渍食品者的发病率高，与该类食品中亚硝酸盐、真菌毒素、多环芳烃化合物等前致癌物或致癌物的含量高有关 吸烟者的胃癌发病率较不吸烟者高50% 三、胃癌的病因 * 幽门螺杆菌(HP)感染 2. HP是引发胃癌的主要因素之一 胃癌高发区人群HP感染率高 HP能促使硝酸盐转化成亚硝酸盐及亚硝胺而致癌 HP感染引起胃粘膜慢性炎症并通过加速粘膜上皮细胞的过度增殖导致畸变致癌 HP的毒性产物可能具有促癌作用 三、胃癌的病因 * HP是一种微弯曲棒状的革兰氏阴性杆菌，存在于多数慢性胃炎病人的胃型上皮表面和腺体内的粘液层中。HP通过其产生的粘附素粘附到胃上皮细胞表面，分泌尿素酶、细胞毒素相关蛋白和细胞空泡毒素及其他一些物质而致病。 * 癌前病变 3. 胃癌的癌前病变有胃溃疡、慢性萎缩性胃炎、胃息肉及术后的残胃炎，这些病变常伴有不同程度的长期慢性炎症过程、胃粘膜肠上皮化生或非典型增生。 三、胃癌的病因 * 遗传因素 4. 胃癌有明显的家族聚集的倾向，有胃癌家族史者的发病率高于普通人群2-3倍 遗传素质使易感者对致癌物质更为敏感 三、胃癌的病因 * 四、胃癌的病变过程 * Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to fight your best for it. Life is more like a battlefield. If you want something, you have to