这种形式的肺癌肿瘤扩散速度快，所以通过手术移除肿瘤的可能性极小。
With this form of lung cancer, tumours spread quickly so it is rarely possible to remove the tumours surgically.
由于肿瘤的存在微转移的可能性，没人知道早做手术于晚做手术是否会带来不同的结果。
No one can say whether or not having surgery earlier would have made any difference because of the possibility of micrometastases.
临床试验是人们帮助医生找到改善健康和肿瘤治疗所进行的研究性工作。
Clinical trials are research studies in which people help doctors find ways to improve health and cancer care.
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