When cancer cells enter the lymph or blood system, they can form secondary tumors elsewhere. the probability of a cure increases. they are known as benign tumors. it becomes easier to stop their spread to other organs?

When cancer cells enter the lymph or blood system, they can form secondary tumours elsewhere.  

Secondary tumours are actually metastasis, cancer that spreads to a different part of the body from where it started. This happens when cancer cells break away from the main tumour and travel via blood or lymphatic system to other certain parts of the body. It is more difficult to treat metastasis because it is not always the same type of an original tumour.