Complete remission: This term is used when all signs of the disease have disappeared after treatment. Although this does not mean that the disease is completely gone, the symptoms have disappeared and the lymphoma cannot be detected using current tests. If this response is maintained for a long period, it is called a durable remission. The longer a patient is in remission the better the prognosis or outcome. However, as with other cancers, the disease could still possibly return and long-term follow-up is necessary.

Cure: Where there are no signs of the disease reappearing, doctors may cautiously begin using the word cure. The ability to cure NHL depends on the type of lymphoma. Many high-grade lymphomas can be cured. Low-grade NHLs tend to reappear, even after long-term remission.

Partial remission: This term is used if the NHL is treated and the tumor shrinks to less than one-half of its original size.

Improvement: This term is used if the tumor rinks following therapy but is still more than one-half of its original size.

Stable disease: The disease does not get better or worse following therapy.

Refractory disease: A cancer that is resistant to treatment.

The International Prognostic Index

An international index for aggressive NHL (diffuse large cell lymphoma) identifies 5 significant risk factors prognostic of overall survival. For each positive risk factor there is a greater risk of relapse.

1. Age (60 years of age),
2. Serum lactate dehydrogenase-LDH (normal versus elevated),
3. Performance status (0 or 1 versus 2-4), (see definition below)
4. Stage (I or II versus III or IV),
5. Extranodal site involvement (0 or 1 versus 2-4).

Patients with 2 or more risk factors have less than a 50% chance of relapse-free and overall survival at 5 years.

Performance status
Performance status is defined as

0 = Normal activity
1 = Symptomatic, full ambulatory
2 = Symptomatic, bed 3 = Symptomatic, in bed 50% of the time not bedridden
4 = 100% bedridden 
5 = dead (don't ask this web master why they include this one)

So if you are 2-4 on this scale then you get one point on the IPI scale. If you are 0-1 on the Performance scale you get zero on the IPI. As you can see the goal is to have a low IPI score.