Meine Gilmara Coelho, Rota Cláudia, Dietz Judite, Sekine Setsuo, Prolla João Carlos
Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
Arq Gastroenterol. 2011 Jan-Mar;48(1):41-5. doi: 10.1590/s0004-28032011000100009.
Gastric cancer is the second most common cause of cancer related death worldwide. Although Helicobacter pylori has been classified as a class I carcinogen, the presence of infection is not a factor that alone is able to lead to gastric cancer, and one of the possible explanations for this is the existence of different strains of H. pylori with different degrees of virulence.
To investigate the association between cagA-positive H. pylori and gastric cancer, using polymerase chain reaction (PCR) for the detection of this bacterial strain.
Twenty-nine patients with gastric cancer were matched by sex and age (± 5 years) with 58 patients without gastric cancer, submitted to upper gastrointestinal endoscopy. All patients were evaluated for the status of infection by H. pylori (through urease test, histological analysis and PCR for the genes ureA and 16SrRNA) and by cagA-positive strain (through PCR for cagA gene).
Evaluating the presence of infection by cagA-positive H. pylori, it was verified that the rate of infection was significantly higher in the group with gastric cancer when compared with the matched controls, occurring in 62.1% and 29.3%, respectively (OR = 3.95; CI 95% 1.543-10.096).
There is an association between cagA-positive H. pylori strain and risk of gastric cancer.
胃癌是全球癌症相关死亡的第二大常见原因。尽管幽门螺杆菌已被列为I类致癌物，但感染的存在并非单独就能导致胃癌的因素，对此一种可能的解释是存在不同毒力程度的幽门螺杆菌菌株。
使用聚合酶链反应（PCR）检测这种细菌菌株，研究cagA阳性幽门螺杆菌与胃癌之间的关联。
29例胃癌患者按性别和年龄（±5岁）与58例非胃癌患者匹配，接受上消化道内镜检查。所有患者均通过幽门螺杆菌感染状况（通过尿素酶试验、组织学分析以及针对ureA和16SrRNA基因的PCR）和cagA阳性菌株状况（通过针对cagA基因的PCR）进行评估。
评估cagA阳性幽门螺杆菌的感染情况时发现，与匹配的对照组相比，胃癌组的感染率显著更高，分别为62.1%和29.3%（OR = 3.95；95% CI 1.543 - 10.096）。
cagA阳性幽门螺杆菌菌株与胃癌风险之间存在关联。
