A 66-year-old man was diagnosed with follicular lymphoma 6 years ago. He responded well to oral chlorambucil chemotherapy. Four years later, his disease recurred and he received intravenous combination chemotherapy along with the therapeutic antibody rituximab.
What prognostic features are useful in planning therapy in this disease?
Follicular lymphoma (FL) is a low-grade malignancy and is the second commonest type of non-Hodgkin lymphoma (NHL). Its incidence increases with age.1
Presentation is usually with asymptomatic lymphadenopathy but patients may have systemic symptoms such as weight loss, fevers, lethargy or night sweats. The bone marrow may be involved with resulting cytopenias. Most patients present at an advanced stage because the disease develops slowly with few symptoms, but localized disease is sometimes seen and this has a good outlook. The behaviour of FL, although indolent in most cases, is variable and there is a significant risk (around 2%–3% per year) of transformation to a histologically aggressive large-cell NHL.2
Diagnosis is usually made from histology of lymph node, bone marrow or other tissue and is supported by the finding of a typical t(14;18) chromosomal translocation. Staging investigations include a computed tomography scan of the neck, chest, abdomen and pelvis and a bone marrow biopsy.
Follicular lymphoma is not curable, with the debatable exception of localized (stage Ia) presentations. For most patients, the disease course is characterized by responses to treatment followed by observation, relapse and further therapy. Subsequent responses tend to be of shorter duration and the median overall survival is 10 years. A significant minority will transform to high-grade NHL, a situation which has a poor outlook.2
A useful prognostic score has been designed employing five risk factors, which are readily available at diagnosis (Table 31.1). This score, the Follicular Lymphoma International Prognostic Index (FLIPI), is useful in the design of studies that stratify therapy according to patient risk group. It can also help clinicians to decide whether more intensive therapy is justified for some patients.3 Three risk groups are identified according to the number of risk factors from the FLIPI, with 5-year survival rates ranging from 52% to 90% (Table 31.2).
Table 31.1The Follicular Lymphoma International Prognostic Index (FLIPI) |Favorite Table|Download (.pdf) Table 31.1 The Follicular Lymphoma International Prognostic Index (FLIPI)
|Parameter ||Adverse factor |
|Age≥60 years || |
|Ann Arbor stage ||III-IV |
|Haemoglobin level ||<120 g/l |
|Serum LDH level ||>Upper normal limit |
|Number of nodal sites ||>4 |
Table 31.2Assigning risk groups using the FLIPI and the impact on survival