Non-Hodgkin lymphoma natural history

Prognosis
The most significant factor in overall prognosis is the grade, or aggressiveness, of the lymphoma. Indolent (low-grade) non-Hodgkin's lymphoma is generally not curable, but is typically slowly progressive and responds temporarily to therapy. Aggressive and highly aggressive (intermediate- and high-grade) NHL's are potentially curable with combination chemotherapy. Long-term survival or cure rates for these diseases vary with a number of prognostic factors.

International Prognostic Index
The International Prognostic Index, or IPI, is the most widely used prognostic system for non-Hodgkin's lymphoma. This system uses 5 factors:
 * Age
 * Lactate dehydrogenase level (a blood test)
 * Performance status
 * Clinical stage
 * Sites of extranodal disease

However, it should be noted that the IPI was developed prior to the introduction of rituximab. As rituximab has become a standard part of therapy for B-cell NHL's, the impact on the prognostic value of the IPI is unclear.

FLIPI
For the subtype of NHL known as follicular lymphoma, a modified version of the IPI called the FLIPI (follicular lymphoma international prognostic index) has been developed. The factors which figure into the FLIPI are age, clinical stage, lactate dehydrogenase level, hemoglobin level, and number of nodal sites involved. As with the IPI, the FLIPI was developed and validated prior to the widespread use of rituximab, so the same caveats apply as were mentioned with the IPI above.