求翻译：胃癌的发生率和死亡率居各类肿瘤前列，化疗是胃癌治疗的一个重要手段，部分病人往往会因胃癌细胞的多药耐药（multidrug resistance，MDR）而导致化疗无效或逐渐由有效转为无效。故研究胃癌的MDR产生机制对提高胃癌的化疗效果，延长病人的生存期有着重要的意义。本文对抗胃癌药物的耐药机制研究现状进行了综述，并对其进行了思考。是什么意思？

Gastric cancer incidence and mortality rates forefront of various types of tumors, chemotherapy is an important means of cancer treatment, some patients because of gastric cancer cells are often multi-drug resistant (multidrug resistance, MDR) caused by chemotherapy or gradually from effective to in

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The stomach cancer formation rate and the mortality rate occupy each kind of tumor front row, the chemotherapy are an important method which the stomach cancer treats, because the partial patients often can the stomach cancer cell multi-medicines bear the medicine (multidrug resistance, MDR) to caus

The front ranks of the various types of cancer incidence and mortality of gastric cancer, chemotherapy is an important means of treatment of gastric cancer, some patients are often due to multidrug resistance of human gastric cancer cell line (multidrug resistance,MDR) caused by chemotherapy gradual

The front ranks of the various types of cancer incidence and mortality of gastric cancer, chemotherapy is an important means of treatment of gastric cancer, some patients are often due to multidrug resistance of human gastric cancer cell line (multidrug resistance,MDR) caused by chemotherapy gradual