The long term follow-up of early stage follicular lymphoma treated with radiotherapy, chemotherapy or combined modality treatment

Impact of age on long-term relative survival benefit of radiotherapy for early-stage grade I-II follicular lymphoma from the SEER database (2000-2015)

The aim of this study was to investigate the effect of age on long-term mortality and net survival benefit of radiotherapy (RT) for early-stage grade I-II FL. Five thousand three hundred and five patients with early-stage grade I-II FL in the SEER database (2000-2015) were identified. Primary therapy included RT alone (RT, 20.7%), chemotherapy alone (CT, 27.6%), combined modality therapy (CMT, 5.9%), and observation (45.8%). Inverse probability of treatment weighting (IPTW) was conducted to balance the treatment arms. Relative survival (RS), the standardized mortality ratio (SMR), and transformed Cox regression were used to compare survival differences between treatments. RT with or without CT had significantly higher 10-year OS (approximately 78%) and RS (>95%), but lower SMR (1.47-1.76), compared with CT (67.8%; 86.3%; 2.35; ps < .001), observation (70.2%; 91.2%; 1.82; ps < .05). RT was an independent predictor of better OS and RS in multivariate analyses (p < .001). No significant interaction between age and RT was identified for RS (Pinteraction = .509) or OS (Pinteraction = .769), indicating similar survival benefits across all-ages patients. RT was associated with long-term OS and net survival benefits in patients with early-stage grade I-II FL, irrespective of age.HighlightsThe pattern and incidence of mortality varied by age-group as elderly patients often die of other diseases other than FL beyond 5 years.Radiotherapy was associated with higher long-term OS/RS and better SMR compared with other approaches, regardless of age.

Advances in Treatment of Follicular Lymphoma

Follicular lymphoma (FL) is a heterogeneous disease with varying prognosis owing to differences in clinical, laboratory, and disease parameters. Although generally considered incurable, prognosis for early and advanced stage disease has improved because of therapeutic advances, several of which have resulted from elucidation of the biologic and molecular basis of the disease. The choice of treatment for FL is highly dependent on patient and disease characteristics. Several tools are available for risk stratification, although limitations in their routine clinical use exist. For limited disease, treatment options include radiotherapy, rituximab monotherapy or combination regimens, and surveillance. Treatment of advanced disease is often determined by tumor burden, with surveillance or rituximab considered for low tumor burden and chemoimmunotherapy for high tumor burden disease. Treatment for relapsed or refractory disease is influenced by initial first-line therapy and the duration and quality of the response. At present, there is no consensus for treatment of patients with early or multiply-relapsed disease; however, numerous agents, combination regimens, and transplant options have demonstrated efficacy. While the number of therapies available to treat FL has increased together with an improved understanding of the underlying biologic basis of disease, the best approach to select the most appropriate treatment strategy for an individual patient at a particular time continues to be elucidated. This chapter considers prognostic factors and the evolving treatment landscape of FL, including recent and emerging therapies, as well as remaining unmet needs.

How to manage early-stage follicular lymphoma

INTRODUCTION

Early-stage follicular lymphoma (FL) is characterized by good prognosis and can be cured with involved-field radiotherapy (IF-RT) in most cases. PET scan is a milestone of diagnostic work-up, with the aim of identifying a truly localized disease; however, staging in most of the studies was without PET.

AREAS COVERED

We have searched in MEDLINE (inclusive dates 1994-2020) data about localized FL management. While high-quality evidence is lacking, current guidelines recommend IFRT or involved-site RT as first-line treatment in limited stages FL. Since a significant proportion of disease relapse occurred in non-irradiated areas, it has been hypothesized that occult disease could be present at diagnosis and could persist after RT, contributing to relapse. Available treatment options include watch-and-wait, chemotherapy, RT plus chemo- or chemo-immunotherapy, and RT combined with rituximab (R).

EXPERT OPINION

RT combined with chemotherapy could increase PFS, but a clear OS benefit is lacking and toxic effects could be unacceptable. A promising strategy is represented by R combined with IF-RT, with low relapse rate outside the radiation fields and without the toxicity reported with chemotherapy. The study of prognostic factors in PET-staged patients, the reduction of RT fields and doses, and a response-adapted strategy represent new perspectives to investigate.

Progression of disease within 24 months of initial therapy (POD24) detected incidentally in imaging does not necessarily indicate worse outcome

Progression of disease within 24 months of initial therapy (POD24) has previously been identified as a predictor of reduced overall survival (OS) for patients with follicular lymphoma (FL). Here we attempt to validate this finding in a retrospective cohort and understand whether the method by which progression is determined, clinically or radiographically, influences POD24 robustness. We reviewed records of 635 patients with FL and included 317 patients in our analysis. POD24 occurred in 21.5% of patients and it was evident that OS was significantly lower in the POD24 group. In multivariate analysis both POD24 and FLIPI were independently associated with inferior OS. POD24 that was detected by incidental routine imaging did not predict reduced OS as opposed to progression that was detected clinically. Although surveillance imaging is generally discouraged in FL, it still is a routine practice by many physicians, and therefore our findings are of significant clinical implications.

Limited stage grade 3 follicular lymphoma patients can experience favorable outcomes with combined modality therapy

Controversy exists regarding the optimal management of limited stage grade 3 follicular lymphoma (FL3). We assessed the treatment outcomes of 190 consecutive patients with stage I-II FL. Fifty two patients had FL3 disease, in whom the median age was 55 years. At a median follow-up of 65 months, 5-year progression-free survival (PFS) and overall survival (OS) rates were 76.6% and 87.6%, respectively. Patients receiving systemic therapy followed by radiation therapy (RT) had a significantly better PFS (p=.003) than those treated with RT alone, but similar OS (p = .476). Patients treated with RT had 100% local control. Compared to 132 patients with grade 1-2 FL, those with FL3 had similar PFS (p = .493) and OS (p  =  .330). Patients with FL3 can experience favorable outcomes when treated with a combination of systemic therapy and RT, comparable to low grade FL.

Treatment of localized-stage follicular lymphoma

Follicular lymphoma (FL) is the most common indolent lymphoma, and it most frequently presents in an advanced stage. Therapeutic considerations for advanced stage are different from those of localized-stage FL, in which radiotherapy (RT) is generally recommended. However, the available evidence suffers from shortcomings that are relatively specific to this clinical entity due to its rarity and long survival with all available treatment modalities, including that most of the existing evidence originated at a time when diagnostic classifications, staging procedures and radiotherapeutic standards were different from those available today and when anti-CD20 monoclonal antibodies were not available. Available treatment modalities include observation, systemic therapy only, RT only and RT in combination with systemic therapy. We review the evidence available with each of them and the data from present-day clinical practice studies as well as briefly discuss what diagnostic and therapeutic developments may take place in the next few years.

Clinical management and outcomes of completely resected stage I follicular lymphoma

Recent studies have revealed the clinical and biological features of stage I follicular lymphoma (FL), but information about patients with stage I FL who underwent total resection after tissue biopsy is limited. Among 305 FL patients diagnosed between 2001 and 2013, clinical stage I disease was observed in 36 patients. Of these, 18 patients underwent total resection after diagnostic tissue biopsy. We used ¹⁸F-fluorodeoxyglucose positron emission CT for staging assessment in 13 of 18 patients (72.2%). The median age was 56.5 years. Six patients (33.3%) were male. The soluble interleukin-2 receptor alpha concentration was significantly lower than in patients with residual disease. Among these 18 patients, 7 patients (38.9%) were treated with a "watch-and-wait" (WW) policy, 7 (38.9%) were treated with involved-field irradiation, and 4 (22.2%) received systemic chemotherapy. Patients with resected disease were treated with significantly different strategies from those with residual disease (p = 0.0026). Five patients experienced relapse during follow-up (median follow-up: 48.2 months). All relapses were distant from the primary site, irrespective of treatment strategy. Among all stage I patients, disease resection was not a significant factor for survival (p = 0.9294). Collectively, the choice of treatment strategy was significantly influenced by patient status. Resection status was not significantly associated with survival after several treatment strategies.

Systemic Front Line Therapy of Follicular Lymphoma: When, to Whom and How

The natural history of follicular lymphoma is usually characterized by an indolent course with a high response rate to the first line therapy followed by recurrent relapses, with a time to next treatment becoming shorter after each subsequent treatment line. More than 80% of patients have advanced stage disease at diagnosis. The time of initiation and the nature of the treatment is mainly conditioned by symptoms, tumor burden, lymphoma grading, co-morbidities and patients preference. A number of clinical and biological factors have been determined to be prognostic in this disease, but the majority of them could not show to be predictive of response to treatment, and therefore can’t be used to guide the treatment choice. CD20 expression is the only predictive factor recognized in the treatment of FL and justifies the use of “naked” or “conjugated” anti-CD20 monoclonal antibodies as a single agent or in combination with chemo- or targeted therapy. Nevertheless, as this marker is almost universally found in FL, it has little role in the choice of treatment. The outcome of patients with FL improved significantly in the last years, mainly due to the widespread use of rituximab, autologous and allogeneic transplantation in young and fit relapsed patients, the introduction of new drugs and the improvement in diagnostic accuracy and management of side effects. Agents as new monoclonal antibodies, immuno-modulating drugs, and target therapy have recently been developed and approved for the relapsed setting, while studies to evaluate their role in first line treatment are still ongoing. Here we report our considerations on first line treatment approach and on the potential factors which could help in the choice of therapy.

[Radiotherapy in localized stages of follicular and diffuse non-Hodgkin's lymphomas]

Treatment with monoclonal antibodies, especially rituximab, is more and more frequent and questions the interest of radiotherapy in limited stages of diffuse B-cell large cell and follicular non-Hodgkin's lymphomas. From a review of literature, it appears that radiotherapy is of interest in bulky disease, patients with incomplete metabolic response, elderly patients receiving short chemotherapy and those with recurrence after exclusive chemotherapy. Finally, this article gives recommendations on available techniques of radiotherapy and doses to be delivered.

New drugs for follicular lymphoma

Despite the improvement in prognosis since the advent of rituximab, follicular lymphoma is still incurable and remains the cause of death of most afflicted patients. With the expanding knowledge of the pathogenesis of B-cell malignancies, in the last few years a plethora of new therapies acting through a variety of mechanisms have shown promising results. This review attempts to analyze the evidence available on these new drugs, which include new monoclonal antibodies and immunoconjugates, the anti-angiogenic and immunomodulatory agent lenalidomide, the proteasome inhibitor bortezomib, inhibitors of B-cell receptor pathway enzymes, such as ibrutinib, idelalisib, duvelisib and entospletinib, BCL2 inhibitors and checkpoint inhibitors. We conclude that despite the high expectations around the new therapeutic options for patients with refractory disease, these new drugs have side effects that require caution with their use, particularly in light of the still short follow up and the lack of both randomized trials and data on combination regimens.

Long-term complication in follicular lymphoma: assessing the risk of secondary neoplasm in 242 patients treated or not with 90-yttrium-ibritumomab-tiuxetan

BACKGROUND

Non-Hodgkin lymphoma patients have a 25% increased risk of secondary primary neoplasms (SPNs). Regarding the controversy about the increased risk of SPN in patients exposed to radioimmunotherapy (RIT), we have analyzed this issue in a cohort of follicular lymphoma (FL) patients treated with/without RIT.

PATIENTS AND METHODS

A retrospective study including all consecutive FL patients diagnosed since 2001 was performed. Demographic, clinical data including the incidence of any kind of neoplasm (excluding basocellular skin carcinoma) were recorded.

RESULTS

A total of 242 patients were registered, male/female: 103/139, mean age: 59.9 yr (15-86), stage IV (57.8%), and Follicular Lymphoma Prognostic Index (FLIPI) low-risk (62.15%) predominance. Ninety-six patients (39.7%) were treated with 90Y-IT. The median follow-up for patients treated or not with 90Y-IT was 61 (8-273) and 38 (1-171) months. With respect to SPN incidence, 38 (15.6%) patients have at least two cancers, in 17 (44.7%), FL was the SPN; for the rest (226), the global incidence of SPNs was 9.3% (21), but there were no differences related to the exposition or not to 90Y-IT (P = 0.26). In seven patients, more than two (2-6) different therapies were registered; four were exposed to fludarabine-based therapy, three to radiotherapy and two to autologous stem-cell transplantation, and in the RIT cohort, two patients developed myelodysplastic syndrome.

CONCLUSION

This is one of the largest single institution reports assessing the risk of SPN in FL patients treated (96) or not (146) with 90Y-IT. It seems that 90Y-IT does not increase significantly the risk of SPN but avoiding its use after fludarabine and other intense cytotoxic schemes is recommended.