More recently, FL patients have been treated with other regimens including: 1) rituximab combined with the chemotherapeutic alkylating agent bendamustine; 2) rituximab combined with the chemotherapeutic agent fludarabine and the inhibitor of Type II topoisomerase, mitoxantrone; and 3) rituximab combined with another immunotherapeutic agent such as galiximab, epratuzumab (monoclonal antibodies directed respectively against the CD80 or CD22 cell surface proteins on immune cells including B cells), or the immunomodulating medication, lenalidomide. While it is too soon to judge the long-term results of the latter regimens, the regimens have shown similar results when analyzed based on poor treatment responses (~10-20% poor responses). Bendamustine with rituximab may be preferable to R-CHOP or R-CVP for treating low-grade (i.e. Grades 1, 2, and possibly 3A) FL; R-CHOP may be preferred in FL that has high-risk characteristics (e.g. high levels of Beta-2 macroglobulin or bone marrow involvement). The combination of lenalidomide with rituximab has shown good potential in treating indolent cases of FL.Studies indicate that maintenance therapy with rituximab following successful induction therapy prolongs progression-free survival; for example one study found progression-free survival after 6 years of treatment was 59.2% in patients treated with rituximab maintenance and 42.7% without this maintenance; however, overall survival at 6 years was similar in the two groups, 87.4% and 88.7%, respectively. Another study found that prolonged maintenance with rituximab did not have any benefits over an eight-month maintenance period.
More than 2 dozen other genes have been reported to be mutated in rare cases of PTFL but in general the genetic abnormalities found in this disorder are fewer and less complex than those in other types of FL. PTFL has an indolent, relapsing and remitting course with a 5-year survival rate of >95%. Patients diagnosed with PTFL have been treated with chemotherapy, surgery, and combinations of these treatments. In general, these patients did well (100% survival with <5% of cases relapsing regardless of treatment modality). More recently, 36 patients have been treated with surgical resection alone followed by observation; all these patients survived with only one having a relapse. Thus, PTFL appears to be a highly indolent type of FL in which multiple studies have reported overall and progression-free survival rates of 100% and >90%, respectively, for >2 years and an estimated probability of 5-year event-free survival rate of ~96%. The therapeutic regimens versus follow-up observations that best treat this disorder in children, adolescents, and adults (adults may require different treatments than children and adolescents) requires further study. Primary follicular lymphoma of the testis
Primary follicular lymphoma of the testis (PFLT), also termed testicular follicular lymphoma, was classified as a distinct form of FL by the World Health Organization in 2016. It is an extremely rare disease that has been recognized as occurring primarily in children and adolescents but also has been reported in 5 adults.