The Follicular Lymphoma International Prognostic Index, or FLIPI, is a standardized guide to help oncological diagnosticians accurately calculate survival rates based on certain factors. The relationship of FLIPI score and lymphoma has been the subject of debate, but it is largely valued as a tool.
Using data collected from 4167 patients from 1985 to 1992, an international panel derived and validated an index based on five diagnostic factors (see below). This was an outgrowth of the more general International Prognostic Index (IPI) for intermediate grade lymphomas. The FLIPI score applies specifically to follicular lymphoma (FL), the most common low grade form of the cancer. It is especially helpful because FL, while slow growing, is notoriously difficult to treat. It is therefore necessary to have a quantifiable measure of survivability.
The five factors which are taken into account when computing the FLIPI are:
1. Over 60 years of age
2. Disease at stage III or IV
3. Five or more nodules or tumors detected, or more than four lymph node groups involved
4. Serum hemoglobin less than 12 g/dL
5. Elevated serum LDH
Each of these factors is assigned one point if positive, the points are totaled to give the final FLIPI score and lymphoma prognoses are based on this score. The following are the three levels of risk into which the FLIPI score can place a person:
0-1 points/Low risk. At this level, a person can expect a 91 percent survival rate at 5 years from diagnosis and 71 percent at ten years.
2 points/Intermediate risk. The five year survival rate is 78 percent and the ten year is 51 percent.
3-5 points/High risk. At the worst level, five and ten year survival rates drop to 53 percent and 36 percent, respectively.
The relationship between FLIPI score and lymphoma survival rates is often misunderstood, however. Too often, a "five year survival rate" is taken to mean that the patient is likely to live only five years. There are two major errors in this reasoning. First, the five year rate can easily include data from patients who went on to live for six, twelve, or even thirty more years. Secondly, with most diseases, survival expectations rise for each year you live after the initial diagnosis. So, for example, the five year survival rate might be 78 percent at diagnosis, but if you are still alive after a year, that rate might increase to 85 percent.
It's important to understand what FLIPI is, how it can be used, and how it is computed, but also keep in mind that it is only one of many tools that you and your doctor can use to design effectively courses of treatment.