Staging and Treatment The significance of this classification is that treatment depends on the stage of the disease as defined by the TNM system. Your doctor has to know the stage to decide on appropriate therapy and to interpret the always evolving guidelines for treatment produced by major cancer centers and research groups.
This system has to be understood precisely so that very critical decisions can be made. Some stages of cancer are best treated surgically, others with radiotherapy , still others with chemotherapy . It is also becoming more and more common to use two of these treatment methods together and sometimes all three. Occasionally, they are given in sequence.
All these decisions are closely correlated with the stage of the tumor . In treating colon cancer, for example, chemotherapy with the drugs 5-fluorouracil and levamisole may be given for Stage III cancer, but not for Stages IA or IIB. Similarly, Stage I prostate cancer may be treated surgically. But surgery is not usually an option by Stage III, when the tumor has extended beyond the prostate.
Although the TNM system is not applicable to all cancers—it is not used with lymphomas, for example—it has now replaced earlier classification systems for tumors in the colon and rectum and is used to stage many other kinds of cancer. As of 1994, it is the recommended staging system for most cancers.
