Which stage in the cancer staging system addresses the involvement of regional lymph nodes?

The cancer staging system, particularly the TNM system, is used to describe the extent of cancer in a standardized way. In this system:

• The "T" category refers to the size and extent of the primary tumor.
• The "N" category specifically addresses the involvement of regional lymph nodes. It indicates whether cancer has spread to nearby lymph nodes and to what extent, which is crucial for assessing the progression of the disease and potential treatment options.
• The "M" category denotes the presence of distant metastasis, indicating whether cancer has spread to other parts of the body beyond the primary tumor site.
• The "C" designation is not part of the TNM system; instead, it may refer to clinical staging, which uses various assessments to evaluate cancer.

Thus, the "N" category is the correct choice as it specifically pertains to the status of regional lymph nodes in the cancer staging process. Understanding the "N" category is vital in determining prognosis and guiding treatment decisions for patients with cancer.