Abstract P067

Excellent outcomes with low intensity treatment based on age and stage in children and adults with nodular lymphocyte predominant Hodgkin lymphoma (NLPHL): a 10yr retrospective analysis of patients from 8 UK centres.

Background: NLPHL is a rare subtype of Hodgkin lymphoma with no standardised treatment (trt). We performed an audit of trt and outcomes in the UK over a period of 10 years.

Methods: This is a retrospective cohort study of patients (pts) all ages diagnosed with NLPHL between 2011-2022 across 8 UK centres. PFS and OS were measured from date of diagnosis (or response) until first event.

Results: Of the total 203 pts, 144 were male (71%). Median age at diagnosis was 38 years (range 8-84); 32 pts (16%) were <18, 130 pts (64%) were stage I-II, 160 pts (83%) did not have B symptoms. A watch and wait (W&W) approach was adopted in 39 pts (19%), of whom 16 (41%) later commenced trt; at a median time of 1.7 years (IQR: 0.9 –3.8), 13 pts (81%) had chemotherapy (CT) and 3 (19%) radiotherapy (RT). Of the remaining 164 pts, 13 (8%) had lymphnode excision only, 59 (36%) had RT, 78 (48%) CT and 14 (8%) had CT+RT (combined modality treatment, CMT). Age and stage influenced trt: W&W pts were older than all other groups, stage I/II pts were more likely to undergo excision or RT. W&W and RT were not used in pts<18: 5 pts (16%) had excision, 26(81%) CT and 1(3%) CMT. For the 92 CT/CMT pts, the most common regimens were: CVP [N=41 (45%); cyclophosphamide, vinca alkaloid, prednisolone] with (26;28%), or without (15;16%) Rituximab (R), R-CHOP[N=24 (26%); rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone] and ABVD [N=19 (21%); doxorubicin, bleomycin, vincristine, dacarbazine] with (6;6%) or without (13;14%) R. Overall response rates did not differ between CT (93%), RT (100%) and CMT (100%): p=0.17. With a median follow up of 4.2 years (IQR 2.2-6.7), 5yr PFS was 80% (95%CI: 72-86) and OS 92% (86-95) for the whole cohort. PFS by stage and initial trt is shown in Fig 1A/B/C. There were 16 deaths, none directly related to lymphoma, 1 related to salvage trt, 4 due to COVID-19. PFS did not differ significantly for pts in PR vs CR after first line trt [HR1.89 (0.70-5.12), p=0.21; Fig.1D]. Transformation to high grade was reported in 8 adults (4%). Delaying trt in 16 patients in the W&W cohort who subsequently required trt did not appear to affect outcome; all are alive (median follow-up: 3.8 yrs), 13/16 (81%) showing no active disease.

Conclusions: Outcomes in NLPHL are excellent with low intensity trt based on age and stage, also in pts in PR at end of first line trt. A W&W approach prevents a proportion of pts needing trt and it does not impact negatively on survival.