中文摘要：

恶性肿瘤是严重威胁人类健康的疾病,肿瘤的转移与复发是治疗所面临的两大难题,但其机制还不清楚,肿瘤干细胞理论时此提出新的解释,其认为肿瘤中存在一小群具有自我更新和不定潜能的肿瘤细胞,可能是肿瘤转移和复发的根源.到目前为止,研究人员已经在白血病、多发性骨髓瘤、乳腺瘤、中枢神经系统肿瘤、肺癌分离并鉴写出了肿瘤干细胞，在胃癌和肝癌中也发现了肿瘤干细胞存在的证据，肿瘤干细胞学说的提出与证实使人类对肿瘤的转移，复发有了新的认识，必将对肿瘤转移、复发的治疗及预防产生重大影响。

英文摘要：

Malignant turmors still remains the disease seriously threatening human being＇s health,Metatasis and neeurrenee are the two hang ups for cancer treatment,but the mechanism is yet uneleur,The theory of the eancer stem cell gives a new explanation that a small group of tumor cells with selfrenewal and indefinite poteney exist in the tumors,which are regarded as the sources in metastasis and recurrence of the tumors.So far tumor stem cells have already been separated and determined in leukemia,multiple my eloma,breast capcer,CNS tumor and lung cancer,The evidernce for existence of tumor stem cells have also been found in gastrie and liver cancet,.The human beings have new cognitions for metastasis and recurrence of turnor with proposal and werification of the theory of the camcer stem cell,which will produce a signifcant in fluence on treatment of tumor and prevention for the metastasis and recurrenee.