Influence of age on long-term net survival benefit for early-stage MALT lymphomas treated with radiotherapy: A SEER database analysis (2000-2015)

Treatment outcome, toxicity, and quality of life of patients with bronchus-associated lymphoid tissue lymphoma

The disease failure patterns and optimal treatment of bronchus-associated lymphoid tissue (BALT) lymphoma are unknown. This retrospective study involved 71 patients with primary BALT lymphoma who had received radiotherapy (RT), surgery, immunochemotherapy (IC), or observation. The median follow-up time was 66 months. The 5-year overall survival and lymphoma-specific survival were 91.2% and 96.1%, respectively, and were not significantly different among treatments. The 5-year cumulative incidence of overall failure for RT, surgery, IC, and observation was 0%, 9.7% (p = .160), 30.8% (p = .017), and 31.3% (p = .039). There was no grade ≥3 toxicity in RT group according to the CTCAE 5.0 reporting system. Quality of life (QoL) was at similarly good levels among the treatment groups. BALT lymphoma had a favorable prognosis but persistent risk of relapse after IC or observation. Given the very low disease failure risk and good QoL, RT remains an effective initial treatment for BALT lymphoma.

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.

Multicenter phase II study of moderate low-dose radiotherapy in indolent non-Hodgkin lymphoma: CLCG-iNHL-01 protocol

Background: Radiotherapy is an effective treatment for indolent non-Hodgkin lymphoma (iNHL); however, the optimal radiotherapy dose remains to be determined. We hypothesize that a suitable dose may exist between 4 and 24 Gy. Methods: This prospective multicenter phase II trial intends to recruit 73 sites of iNHL patients, who will receive involved-site radiotherapy of 12 Gy in four fractions. The primary objective is the 6-month clinical complete response rate. Tumor tissue, blood and conjunctival specimens will be collected to identify potential predictive biomarkers. Discussion: The CLCG-iNHL-01 trial will evaluate the efficacy and toxicity of 12 Gy in patients with iNHL and provide information on a novel hypofractionation regimen of low-dose radiotherapy. Clinical Trial Registration: NCT05543070 (ClinicalTrials.gov).

Decreased lymphoma-related deaths and improved long-term relative survival with radiotherapy for early-stage diffuse large B-cell lymphoma in the rituximab era

BACKGROUND

We aimed to investigate the incidence of lymphoma-related death (LRD) and the long-term net survival benefit of radiotherapy (RT) for early-stage diffuse large B-cell lymphoma (DLBCL) in the rituximab era.

METHODS

10,841 adults diagnosed with early-stage DLBCL between 2002-2015 were retrospectively analyzed using data from the Surveillance, Epidemiology, and End Results database. Primary therapy was categorized into combined-modality treatment (CMT, n = 3,631) and chemotherapy alone (n = 7,210). Competing risk analysis was used to evaluate the cumulative incidence of mortality. Inverse probability of treatment weighting (IPTW) was used to balance groups. The net survival benefit of RT was estimated through relative survival (RS), standardized mortality ratio (SMR), and transformed Cox regression, while controlling for background mortality.

RESULTS

Patients initially treated with CMT had a lower cumulative incidence of LRD compared to those who received chemotherapy alone (HR 0.63, 95%CI: 0.57-0.69; P < 0.001). The 10-year overall survival (OS), RS, and SMR for CMT were 66.1%, 85.0%, and 1.71 respectively, which were significantly better than those for chemotherapy alone (53.0%; 69.8%; 2.62; all P < 0.001). IPTW and multivariable analysis revealed that the addition of RT led to better OS (HR 0.67, 95%CI: 0.62-0.71; P < 0.001) and RS (HR 0.69, 95%CI: 0.65-0.74; P < 0.001). Moreover, compared with chemotherapy alone, the benefit of OS and RS for CMT increased over time within 10 years of diagnosis.

CONCLUSION

RT reduced LRD and improved the long-term net survival in early-stage DLBCL in the rituximab era. Further prospective studies are warranted to assess the specific patient population that would benefit the most from consolidative RT in early-stage DLBCL.