What does M1 signify in cancer staging?

M1 signifies the presence of distant metastasis in cancer staging. This term is part of the TNM staging system, where 'M' stands for metastasis. When cancer is classified as M1, it indicates that the cancer has spread from the original site to distant organs or lymph nodes. This information is crucial for determining the extent of disease progression and guiding treatment decisions. Recognizing M1 status allows healthcare professionals to tailor patient management strategies appropriately, as distant metastasis often indicates more advanced disease which may require systemic therapies rather than localized treatments. Understanding the implications of M1 staging is vital for accurate prognosis and treatment planning in oncology.