The "chronology of cancer" is a concept that describes the nature of cancers through the measure of time. The field extends from carcinogenesis to development, progression, and metastasis. Carcinogenesis is a multi-step process, which results from the accumulation of multiple genetic or epigenetic alterations. Various chronologies of gastrointestinal cancers have been reported for carcinogenesis caused by different risk factors. These chronologies are useful for developing cancer prevention strategies. The tumor growth rate is one of the most important factors in this field. Combining the factors of time and tumor growth enables us to estimate the time at which cancer or metastasis occurred, retrospectively, and to predict the survival of cancer patients, prospectively. It is noteworthy that these chronologies differ significantly among individual cases, even of cancers derived from the same organ. Thus, they are useful for individualization. We can apply the knowledge obtained in this field to the basic research and the diagnosis and treatment of cancers. The chronology of cancer is a classical but interesting field, which helps us consider and explore the essence of cancer. We review the topics related to the chronology of gastrointestinal cancer, ranging from carcinogenesis to metastasis.
Keywords: Chronology; Gastrointestinal cancer; Tumor growth rate.