Pattern of Care in Indolent Non Follicular Lymphoma: A Report from NF10 Project, an International, Prospective, Observational Study Coordinated By the Fondazione Italiana Linfomi

Background: Indolent non follicular B-Cell Lymphomas (INFL) are a heterogeneous group of lymphomas and include small lymphocytic lymphoma (SLL), lymphoplasmacytic lymphomas (LPL) and marginal zone lymphomas of splenic (SMZL), nodal (NMZL) and extranodal (ENMZL) subtypes. In 2010 the NF10 study was started by the Fondazione Italiana Linfomi as a prospective registry specifically devised for investigating the prognosis of this group of lymphomas. We provide a preliminary report describing registered cases with an emphasis on initial therapy.

Methods: The registration of consecutive adult patients with newly diagnosed INFL and no exclusion criteria is ongoing at a dedicated website via secure HTTP protocols. For the purposes of the study in addition to the conventional INFL subtype, the category of disseminated MZL and CD5- low grade lymphoma were also considered. So far the study has been activated in 65 centers in Europe and South America.

Results: Between July 2010 and July 2015, 665 cases have been registered. The current report is based on 395 cases that have been validated. Forty-seven (12%) cases were registered as SLL, 76 (19%) as LPL, 59 (15%) as CD5-low grade and 213 (54%) as MZL, including 73 (18%) SMZL, 18 (5%) NMZL, 81 (21%) ENMZL or 41 (10%) disseminated subtypes.

Median age was 67 years (range 29-94), 53% of patients were males; Ann Arbor stage was III-IV in 79%; 14% had B symptoms, 7% had ECOG performance status > 1, lactate dehydrogenase and b2-microglobulin were elevated in 70% and 54% of cases, respectively. Six percent of cases were HCV positive (HCV+ rate was 7.5% among MZL cases). Regarding HBV infection, 21% of patients were HBcAb-positive and 3% of patients were HBsAg-positive.

Immediate systemic therapy was planned in 50% of patients. SMZL, SLL and CD5-low grade were the subtypes with the lower rates of immediate therapy (44%, 46% and 24% respectively) whereas ENMZL were addressed to systemic therapy in 67% of cases. When systemic therapy was prescribed rituximab (R) was used in 88%. In 81% of patients R was combined to cytotoxic therapy including alkylating agents in 40%, CHOP-like in 18%, bendamustine in 17% and fludarabine in 6%.

ENMZL and CD5-low grade had the highest rates of R-alkylating use (61% and 64%); SMZL and MZL were frequently treated with R-CHOP like regimens (35% and 40%).

Young age at diagnosis (less than 60 years) and increased b2-microglobulin were more frequently associated with patients requiring immediate systemic therapy. With 22 months of median follow up, 2-year progression free survival and overall survival (OS) were 88% (95CI: 83-92) and 95% (95CI: 91-97) respectively; the initial choice of deferring immediate therapy did not impact on OS.

Conclusions: We provide a complete report on the initial approach to patients with INFL showing that immediate therapy is required in half of the cases with a heterogeneous approach among INFL subtypes. The majority of patients requiring therapy was treated with the combination of R and alkylating agents. The NF10 study confirms that a web-based world-wide cooperation allows the collection of a relevant and complete data set, providing a platform for future prognostic and pathobiological studies in order to identify novel and more efficient therapeutic targets.