What is the primary purpose of the TNM staging system?

The primary purpose of the TNM staging system is to assess the extent of cancer spread in the body. This system evaluates three key components: the size and extent of the primary tumor (T), whether the cancer has spread to nearby lymph nodes (N), and whether there are metastases to distant sites (M). By systematically categorizing these factors, the TNM staging provides a standardized method for healthcare professionals to determine the overall stage of the cancer. This information is crucial because it informs treatment decisions, prognosis, and helps in evaluating the patient’s response to therapy.

The other options, while related to cancer care, do not represent the core function of the TNM system. Classifying types of cancer and determining traditional treatment options are important aspects of oncology but are not the primary focus of the TNM staging. Similarly, measuring patient recovery rates is related to outcomes after treatment rather than the assessment of the initial extent of disease. The TNM system is specifically designed as a diagnostic and staging tool, making option B the most accurate choice.