What percentage of follicular lymphomas are due to t(14;18) translocation issues?

From the Guidelines

Approximately 85% of follicular lymphomas are due to translocation issues, specifically the t(14;18) translocation, as indicated by the presence of BCL2+ or t(14;18)+ in these cases. This percentage is based on the guidelines provided by the National Comprehensive Cancer Network 1. The t(14;18) translocation leads to the overexpression of the BCL2 protein, which plays a crucial role in inhibiting programmed cell death (apoptosis), thereby allowing abnormal B-cells to accumulate in lymph nodes. Key points about follicular lymphoma and its genetic basis include:

• The involvement of the BCL2 gene on chromosome 18 and the immunoglobulin heavy chain gene on chromosome 14 in the t(14;18) translocation 1.
• The use of the t(14;18) translocation as a diagnostic marker due to its high prevalence in follicular lymphoma 1.
• The existence of other genetic alterations in about 10-15% of follicular lymphomas that lack the t(14;18) translocation 1. Understanding the genetic basis of follicular lymphoma, such as the role of the t(14;18) translocation, has significant implications for the development of targeted therapies aimed at counteracting the effects of BCL2 overexpression in the treatment of this type of non-Hodgkin lymphoma 1.

From the Research

Translocation Issues in Follicular Lymphomas

• The majority of follicular lymphoma (FL) cases are characterized by the t(14;18)(q32;q21)/IGH::BCL2 translocation, which leads to the overexpression of BCL2 2.
• Approximately 85% of FL cases harbor this translocation, which is referred to as classic FL in the current World Health Organization classification 2.
• In contrast, about 15% of FL cases are negative for the t(14;18) translocation, which can present diagnostic challenges 2.
• The t(14;18)/IGH-BCL2 translocation is also present in 60% to 90% of nodal follicular lymphomas, and its prevalence and clinical significance have been examined in gastrointestinal follicular lymphomas 3.
• The presence of the t(14;18)/IGH-BCL2 translocation was detected in 81% of gastrointestinal follicular lymphoma cases, and its presence was associated with an adverse clinical course 3.

Prevalence of Translocation

• The overwhelming majority of FL cases have the characteristic t(14;18) translocation involving the IgH/bcl-2 genes 4, 5.
• The t(14;18) translocation is present in almost all cases of FL, resulting in the overexpression of BCL2, an anti-apoptotic protein 6.