What is defined as a new tumor or frank cancer?

The term "de novo" refers to a new tumor or frank cancer that arises independently, rather than from an existing tumor or as a result of metastasis. In oncology, it specifically denotes the initial occurrence of cancer that has not developed from preexisting cancerous cells. This concept is essential in clinical contexts, as it helps distinguish between new primary tumors and tumors that have developed due to the spread of cancer from one part of the body to another.

Other terms used in oncology can describe different processes related to cancer. Metastasis refers to the spread of cancer cells from the original tumor to other parts of the body, indicating that the cancer is not new but rather an extension of an existing disease. Progression denotes the advancement of cancer in terms of size or spread but does not imply the creation of a new tumor. Relapse, on the other hand, describes a scenario where cancer returns after a period of improvement, not the emergence of a completely new cancer. Hence, "de novo" is clearly the correct choice when looking for a term that signifies a new and independent tumor formation.