Pb2256: epidemiology and outcomes of hodgkin lymphoma in uruguay. a national registry

Topic: 17. Hodgkin lymphoma - Clinical Background: Hodgkin Lymphoma (HL) accounts for 10% of lymphomas in adults. In Uruguay, incidence is 2.7/100.000/year but no data regarding epidemiology, prognostic factors, treatment patterns and outcomes are available. Uruguayan Group for the Study of Lymphomas (GULI) have collected this information among patients from 10 private and public institutions creating the first national registry on this disease. Aims: Describe clinical characteristics of patients with classic HL in Uruguay, treatment patterns and outcomes in our country. Methods: Observational registry of patients older than 15 years with confirmed HL from participating institutions diagnosed from 2009-2021. Results: 294 patients were included. 54% from public institutions, 46% from private ones. 53% were male. Median age at diagnosis was 35 (15-83) 8 patients (2.7%) HIV positive. Nodular sclerosis subtype accounted for 80% of cases, 10% mixed cellularity, 3% lymphocyte depleted, 2% lymphocyte-rich, 0,7%, Primary nodular lymphocyte-predominant, no data in 4,3%. Bone marrow biopsy was performed in 65% of patients and in 45% of those staged by PET/CT Advanced stage disease was observed in 164 (58%) patients, more frequently in patients from public institutions (64.7%) than in private ones (50%) p=0,012. 52% had B symptoms and 23% were Bulky. 120 were early stage disease, 50 (42%) favorable and 69 (58%) unfavorable. PET/TC was used for staging in 50%, the rest were stratified by CT scan. First line therapy consisted of AVBD in 94%, median number of cycles was 6 (1-8) both in early and advanced stage disease. Interim PET/TC was used in 107(39%), 65% of whom achieved a compete metabolic response at this stage. Complete remission was observed in 73,8% of patients, 80% evaluated by PET. We have seen an increasing use of PET/TC in the last years in accordance to government funding of this study. Staging PET was approved in 2015, interim PET in 2017 and End of Treatment (EOT) PET in 2012. (Figure 1) With a median follow up 46 months (0,85-163,1), median OS was not reached, 5-years OS was 89%. No OS difference between patients treated in public and private institutions was observed. Patients with early stage have an OS advantage over those with advanced stage in our cohort, with a 5-year OS of 94% and 84% respectively (p=0,017). Although we found a trend to a better OS in patients in CR, it was not statistically significant. (p=0.271) 55 (19,2%) patients from the cohort were refractory or relapsed. Median progression free survival has not been reached. 5-year PFS was 75%. No difference in PFS regarding stage at diagnosis was observed. However, a longer PFS was seen in patients from private institutions; 5 year FPS 84% vs 66% in public ones (p=0.008) Summary/Conclusion: We have observed that HL in Uruguay presents more frequently in advanced stages and this is particularly more frequent among patients from the public system. One reason could be the delay in seeking medical attention in these patients. Early-stage favorable HL occurs in 17% and unfavorable in 25%. Median number cycles of treatment were 6 irrespective of the calculated risk. This is important to remark due to current recommendations for the treatment of early and favorable disease with 2-4 cycles of ABVD. The most widely used treatment was ABVD and end-of treatment CR was achieved in 73.8%. 5-year OS was 89% and PFS 75%, similar to that reported by the SEER registry and by Cancer Research UK. We found a difference in PFS between patients treated in public versus private centers, favoring the privates ones. This is the first multicenter study that shows the epidemiology and characteristics as well as the management of HL in Uruguay, highlighting the importance of national registries Keywords: Epidemiology, Hodgkin’s lymphoma