Relapsed/Refractory Follicular Lymphoma Prognosis and Epidemiology

The prognosis and epidemiology of relapsed and refractory follicular lymphoma have not been well documented, as most reports focus on follicular lymphoma as a whole. As such, this article includes some references relating to follicular lymphoma, with some details about relapsed and refractory forms of the disease.

Prognostic Factors

For patients with follicular lymphoma, the overall 5-year survival rate is approximately 72-77% and the median survival rate is just under ten years. However, the current prognosis rates are expected to be higher than that indicated in previous research, due to the introduction of new, targeted therapies such as rituximab.

Patients with relapsed or refractory follicular lymphoma have a poorer prognosis than those with follicular lymphoma who successfully reach remission for a prolonged period. The use of targeted treatments such as rituximab has improved rates of remission.

Factor that may influence the prognosis for the patient include age, severity of the lymphoma, hemoglobin count, involvement of lymph nodes, and LDH level. These factors have been compiled together to create a prognostic index, as described below.

Follicular Lymphoma International Prognostic Index (FLIPI)

The Follicular Lymphoma International Prognostic Index (FLIPI) is used to identify patients who are most likely to respond well to treatment and those who are most likely to relapse, based on prognostic factors. The following factors are considered in the index:

• Age: good for younger than 60 years, poor for older than 60 years
• Stage: good for stage I or II, poor for stage III or IV
• Hemoglobin: good for 125 g/L or more, poor for less than 125 g/L
• Lymph node involvement: good for 4 or less, poor for more than 4 nodes
• LDH: good for normal LDH, poor for increased LDH.

Patients are assigned an index score based on the number of factors for which they are categorized as poor. Therefore, a lower score is associated with a more positive prognosis. Patients with a score of 4 or 5 have a 10-year survival rate of 36%, whereas those with a score of 0-1 have a 71% survival rate.

Epidemiology

Follicular lymphoma is a type of non-Hodgkin lymphoma (NHL), which is the fifth most common type of cancer diagnosed in the United States. According to the America Cancer Society, it is estimated that 72,000 cases of non-Hodgin lymphoma will present in 2016. Of these, follicular lymphomas account about 1 in 5 cases; more than 14,000 cases.

The incidence of non-Hodgkin lymphoma is higher in more developed countries when adjusted for age. There is a notably low incidence in some countries, such as China and Japan. Individuals of certain ethnic backgrounds are more likely to be affected, such as those of Jewish origin.

Both males and females appear to be equally affected by follicular lymphoma, including the relapsed and refractory forms of the disease.  Elderly individuals have a higher risk of follicular lymphoma and the median age at diagnosis is between 60 and 65 years. In line with this, the disease is very rare in children and adolescents.

References

• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459616/
• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3775637/
• http://asheducationbook.hematologylibrary.org/content/2013/1/561.full
• http://emedicine.medscape.com/article/203268-overview
• http://www.cancer.ca/en/cancer-information/cancer-type/non-hodgkin-lymphoma/non-hodgkin-lymphoma/types-of-nhl/follicular-lymphoma/?region=on