Cancer is one of the main causes of morbidity and mortality worldwide. The most frequent types of this disorder are lung, breast, colorectal, prostate, stomach and liver cancers. In 2012, approximately 14.1 million new cases of the disease were registered, resulting in about 8.2 million of deaths . Most of these deaths could be avoided if an early diagnosis is achieved. As a result, many efforts have been made to develop new methods for an early and accurate cancer diagnosis. It would allow less aggressive and mutilating treatments of patients, leading to better prognostics with greater chances of cure. Besides that, it would result in a reduction of cancer treatment costs at advanced stages and metastasis.