The Future of TNM Staging in Rectal Cancer: The Era Of Neoadjuvant Therapy

Despite profound changes in the treatment of rectal cancer in recent years, staging has remained unchanged. There is no doubt that the Tumor Node Metastasis (TNM) staging system is of major importance in predicting prognosis, and in selecting patients for adjuvant therapy or participation in clinical trials. However, the application of neoadjuvant therapy changes the meaning of the different stages and, because of histologic changes, makes staging difficult. This article evaluates the various therapies, their implications for staging, and its meaning. It also indicates problems and proposes a standard for reporting.