Addition of Rituximab to Front-Line-Treatment Highly Improved the Outcome of Elderly Patients with Follicular Lymphoma: a Population Based-Study From the Modena Cancer Registry
Authors: Luminari Stefano , Biasoli Irene , Marcheselli Luigi , Bellei Monica , Dondi Alessandra , Mastronardi Sonia , Cesaretti Marina , Federico Massimo 
Published: October 2019

Abstract 5077

Background:

The benefit of adding Rituximab to combination chemotherapy in Follicular Lymphoma (FL) has been established in several randomized clinical trials (RCT). All of them have shown improvements in response rates, time to progression or overall survival (OS). The aim of the study was to assess the impact of the introduction of Rituximab in the treatment of FL in the general population of elderly patients, usually not included in RCT.

Methods:

All FL patients diagnosed in the province of Modena, Italy that had been diagnosed between 1997 and 2010 were identified from the archives of the Modena Cancer Registry that covers a population of approximately 600. 000 people. In the studied region Rituximab was available for first line treatment of FL since 2004. Therefore, for study purposes patients were grouped according to the year of diagnosis in 2 study periods (1997–2003, and 2004–2010). Elderly patients were defined using a cut off for age at 60 years. Clinical and treatment characteristics and also OS were compared according to the period of diagnosis and also, regarding the use or not of Rituximab as part of first line treatment. Moreover, a Cox regression analysis was performed to identify clinical factors and treatment characteristics associated with OS.

Results:

A total of 340 FL patients were identified of whom 177 (52%) were older than 60 years. No difference was found regarding clinical characteristics at diagnosis (age, gender, stage, bulky disease and LDH level) among study periods. Regarding treatment, no difference was found for the first general approach (watch and wait, chemotherapy or radiotherapy) across time. Among 229 patients initially treated with chemotherapy, antracyclines (ADM) or fludarabine (F)-based-regimens were the most frequently used. However, the use of ADM and/or F-based-regimens decreased from 82% (85/104) in the first period to 66% (83/125) in the last period (p=0. 03). Elderly patients (67%; 83/124) received less frequently ADM or F-based-regimens in comparison with younger patients (81%; 85/105) (P<0. 001). In contrast, the use of Rituximab alone or as part of front line treatment remarkably increased from 15% (16/104) in the first period to 94% (118/125) after 2003 (p<0. 001). This increase was also observed among elderly patients (8% (4/49) in the first period and 92% (69/75) in the last period, p<0. 001). After a median follow up of 68 months (range 8 to 176) for living patients, median OS was not reached. In univariate analysis factors associated with inferior OS were older age (>60), period of diagnosis before 2004, no use of Rituximab and abnormal LDH levels. The 5-years OS increased from 73% to 85% moving from first to second study periods (p=0. 008). In the Cox-Regression analysis, age > 60 (HR 11. 27 95%CI 5–25) and abnormal LDH level (HR 2. 7 95%CI 1. 56–4. 8) at diagnosis were identified as independent adverse risk factors. In contrast, the use of Rituximab yielded a protective effect (HR 0. 4 95%CI 0. 23–0. 79). In multivariate analysis period of diagnosis and use of Rituximab were mutually exclusive. Comparing young with elderly patients, only the latter group had a significant improvement in OS across the study periods: among the young, the 5-years OS in the first and second period was 89% and 98%, respectively, p= 0. 07; and among the elderly the 5-years OS in the first and second period was 58% and 72%, respectively p=0. 02.

Conclusion:

The present population based study showed a remarkable improvement in OS of FL patients after 2003, as a consequence of introduction of Rituximab as part of first line treatment. This improvement was mostly pronounced in the elderly population.

Disclosures:

No relevant conflicts of interest to declare.