When coding the grade of a tumor, which of the following statements is true?

The statement indicating that only the primary tumor grade should be coded is accurate because it reflects standard practice in oncology coding. Tumor grading is intended to provide information about the differentiation of the cancer cells, which is most accurately represented by the primary tumor. The primary tumor is the original site of the cancer, and its grade is the most relevant indicator of the aggressiveness of the disease at diagnosis.

In coding, the focus is typically on the characteristics of the primary tumor because this is where treatment decisions and prognostic evaluations are primarily based. Although metastatic tumors can exhibit different characteristics from the primary tumor, their grades are often not used for initial treatment planning. Therefore, coding the grade of the primary tumor aligns with established protocols and guidelines in oncology, ensuring consistency and accuracy in the treatment and research processes.