ABSTRACT
Cancer is a disease with widespread occurrence, high death rate and recurrence. According to the data from the agencies of United States Centers for Disease Control and American Cancer Society, cancer is becoming the second leading cause of death, surpassing the cerebrovascular diseases due to the above-mentioned traits of cancer. It is estimated that one out of four deaths is attributed to cancer in the United States. Survival of a cancer patient depends largely on early detection, drugs and surgery. However, the yearly cancer death rate has not signifi cantly decreased despite the use of more powerful diagnostic tools, more effective drugs and more consummate surgical techniques for recent several decades. This phenomenon could be explained by the following reasons: one is that the diagnosis for cancer is usually not early enough when the primary tumor has metastasized and invaded other organs, which is beyond surgical intervention; another is that the current used therapy methods for cancer lack specifi city toward cancer tissue; the last one is due to the easy recurrence of cancer. Therefore, the development of technology that is specifi c, reliable and handy for detecting cancers at early stages functioning as the fi rst-line guidance is of utmost importance, the development of new drugs targeting cancer tissue with minimal side effect, surgical techniques that only selectively removes diseased tissues without causing collateral damage, and techniques for monitoring therapeutic responses in real-time is an inevitable task for cancer researchers.
