Stages of Mesothelioma

Knowing the stage of your mesothelioma will be a factor in helping your doctor formulate a treatment plan. The most definitive and most widely used system is the TNM International Staging System for Diffuse Malignant Pleural Mesothelioma, also called the International Mesothelioma Interest Group System. This system takes into consideration Primary Tumor (T), Lymph Nodes (N) and Metastases (M). There is no established staging system for peritoneal mesothelioma. Peritoneal patients may be staged according to the general TNM system for cancer, or on the bulk of the tumor present (i.e., minimally bulky, moderately bulky, etc.). Because the TNM system is very in depth, and difficult for interpretation by lay persons, following is a simplified version. Stage I is the earliest stage; Stage IV the most advanced.

Stage I

Mesothelioma involves the right or left pleura and may also have spread to the lung, pericardium or diaphragm on the same side. Lymph nodes are not involved.

Stage II

Mesothelioma has spread from the pleura on one side to nearby lymph nodes next to the lung on the same side. It may also have spread into the lung, pericardium or diaphragm on the same side.

Stage III

Mesothelioma has invaded the chest wall, muscle, ribs, heart, esophagus or other organs in the chest on the same side with or without spread to lymph nodes on the same side as the primary tumor.

Stage IV

Mesothelioma has spread into the lymph nodes in the chest on the side opposite the primary tumor, or extends to the pleura or lung on the opposite side or directly extends into organs in the abdominal cavity or neck. Any distant metastases in included in this stage.