Table 2. Anatomic Stage/Prognostic Groupsa continued...
The Ann Arbor staging system is commonly used for patients with NHL.[10,11] In this system, stage I, stage II, stage III, and stage IV adult NHL can be subclassified into A and B categories: B for those with well-defined generalized symptoms and A for those without such symptoms. The B designation is given to patients with any of the following symptoms:
- Unexplained loss of more than 10% of body weight in the 6 months before diagnosis.
- Unexplained fever with temperatures above 38°C.
- Drenching night sweats.
Occasionally, specialized staging systems are used. The physician should be aware of the system used in a specific report.
The E designation is used when extranodal lymphoid malignancies arise in tissues separate from, but near, the major lymphatic aggregates. Stage IV refers to disease that is diffusely spread throughout an extranodal site, such as the liver. If pathologic proof of involvement of one or more extralymphatic sites has been documented, the symbol for the site of involvement, followed by a plus sign (+), is listed.
Table 3. Notation to Identify Specific Sites
|N = nodes||H = liver||L = lung||M = bone marrow|
|S = spleen||P = pleura||O = bone||D = skin|
Current practice assigns a clinical stage (CS) based on the findings of the clinical evaluation and a pathologic stage (PS) based on the findings made as a result of invasive procedures beyond the initial biopsy.
For example, on percutaneous biopsy, a patient with inguinal adenopathy and a positive lymphangiogram without systemic symptoms might be found to have involvement of the liver and bone marrow. The precise stage of such a patient would be CS IIA, PS IVA(H+)(M+).
A number of other factors that are not included in the above staging system are important for the staging and prognosis of patients with NHL. These factors include the following:
- Performance status.
- Tumor size.
- Lactate dehydrogenase (LDH) values.
- The number of extranodal sites.
To identify subgroups of patients most likely to relapse, an international prognostic index was compiled for 2,031 patients with aggressive NHL. After validation by several cancer centers,[13,14] the major cooperative groups have used this index in the design of new clinical trials. The model is simple to apply, reproducible, and predicts outcome even after patients have achieved a complete remission. The model identifies five significant risk factors prognostic of overall survival (OS):
- Age (<60 years vs. >60 years).
- Serum LDH (normal vs. elevated).
- Performance status (0 or 1 vs. 2–4).
- Stage (stage I or stage II vs. stage III or stage IV).
- Extranodal site involvement (0 or 1 vs. 2–4).