The distribution of forkhead box protein 3 (FOXP3)+ T-regulatory (TREG) cells predicts survival and transformation risk in follicular lymphoma, according to a new study. “No biological predictors of risk of transformation existed in the literature,” says investigator Randy Gascoyne from the BC Cancer Research Centre, Canada.

Follicular lymphoma has a highly variable clinical progression and can transform into an aggressive and potentially fatal lymphoma. Immunosuppressive TREG cells have been shown to affect antitumor responses and previous studies on the association of TREG cells with survival in follicular lymphoma have provided contradictory results. “Virtually all these studies have been hindered by including patients treated with different therapies,” adds Gascoyne.

Farinha et al. used a cohort of 105 patients with follicular lymphoma from a previous phase II clinical trial in which all patients had received the same treatment. The researchers constructed tissue microarrays using diagnostic biopsies from the patients, stained for TREG cell markers (CD4, CD25 and FOXP3) and quantified the number and distribution of TREG cells in the samples. They found that the pattern, but not the number, of FOXP3+ TREG cells in or around the neoplastic follicles was associated with survival in follicular lymphoma and had a significant impact on overall survival, progression-free survival, and crucially, risk of transformation.

Gascoyne plans to validate these results for follicular lymphoma using in patients who have received chemotherapy and rituximab.