PATIENTS WITH FOLLICULAR LYMPHOMA (FL) IN MAINTAINED COMPLETE RESPONSE (CR) AT 30 MONTHS SHOW A SURVIVAL SIMILAR TO A SEX‐ AND AGE‐MATCHED SPANISH GENERAL POPULATION

Abstract

Introduction: FL is an indolent lymphoma characterized by the responsiveness to therapy followed by repeated relapses. The use of immunochemotherapy has allowed high CR rates with substantial advances in PFS and OS. However, patients who experience early progression still have poor outcome, whereas on the contrary, life expectancy of those with durable responses seems reasonably good. CR at 30 months has recently been suggested as potential surrogate for PFS in these patients. The aim of the present study was to analyze the group of patients in maintained CR at 30 months and to compare their OS with that of the general population. Methods: The training cohort consisted of 263 patients (median age, 59 years; F/M, 142/121) consecutively diagnosed with FL grades 1, 2 or 3a in two centers between 2004 and 2014, with the only criterion being the need of treatment that consisted of rituximab combinations (61% R-CHOP). Response was evaluated by CT scan. A “land-mark” at 30 months from diagnosis was established to assess survival. Relative survival (RS) was analyzed with respect to the sex- and age-matched Spanish population. An independent series of 693 patients (median age, 58 years; F/M, 380/313) diagnosed with FL in 19 Spanish hospitals from the GELTAMO group were used as validation cohort. Results: In the training cohort, 79% of patients achieved CR/CRu, 17% PR and 4% showed failure to treatment. After a median follow-up of 7.1 years, 10-year PFS and OS were 49% and 78%, respectively. During the follow-up prior to 30 months, 66 patients (43 in CR/CRu and 23 in PR) eventually progressed, whereas 21 PR patients reached CR status. As shown in the table, after excluding 14 patients who died before the land-mark, 188 were in maintained CR and 61 had eventually progressed. In table and figure, OS and RS of these groups are detailed. No decrease in the life expectancy was observed for patients in CR at 30 months. Interestingly, in this group, the quality of response (CR vs. PR) nor PET/CT-assessed response (negative vs. positive) did not influence significantly RS. Initial high ß2 microglobulin and high-risk FLIPI were associated with poorer OS. The impact of CR at 30 months on RS was validated in the independent GELTAMO series as shown in the table. Conclusion: Patients with FL treated with immunochemotherapy who maintain CR at 30 months from diagnosis show similar survival than a sex- and age-matched general population. This information should be taken into account when these patients are considered candidate for potentially toxic treatments. (Table Presented).