| I (Approximately 13% of all patients are in this group.) |
A localized tumor that is completely removed with pathologically clear margins and no regional lymph node involvement. |
| II (Approximately 20% of all patients are in this group.) |
A localized tumor that is grossly removed with (a) microscopic disease at the margin, (b) involved, grossly removed regional lymph nodes, or (c) both (a) and (b). |
| III (Approximately 48% of all patients are in this group.) |
A localized tumor with gross residual disease after incomplete removal or biopsy only. |
| IV (Approximately 18% of all patients are in this group.) |
Distant metastases are present at diagnosis. |
