Hodgkin Lymphoma Outcomes: Can We Expect Ethnic Parity in a Hispanic Prevalent Population?

BACKGROUND

It is estimated that 8110 persons will be diagnosed with Hodgkin Lymphoma (HL) in the US during 2019, but the advent of new treatment options has increased the cure rate to at least 80%. It has been reported that the rates of HL are lower in the adolescent and young adult (AYA) Hispanic population but significantly higher in the Hispanic population older than 65. The relative survival estimates are stated to be similar between AYA Hispanics (HI) and non-Hispanics (NH) but for ages 65-84, HI have a significantly higher mortality rate. Pediatric studies have suggested that ethnicity plays a role in outcomes in patients with HL but there is limited data in the adult population. There is an unmet need in the field, where dossiers on underrepresented ethnic minorities need to be carefully considered and compared to existing data. Therefore, our study aims to compare survival outcomes in Hispanics vs Non-Hispanics with HL, who were treated at the only NCI designated cancer center of South Texas. To our knowledge this is the largest cohort of HL patients from a single academic institution that serves primarily Hispanics.

METHODS

We located and retrospectively analyzed a total of 616 patients with diagnosis of Lymphoma (HL and NHL) by International Classification of Diseases (ICD) codes and identified 116 cases of HL; all the patients received care at UT Health San Antonio, between 2008-2018. Key variables for each patient included age, gender, race/ethnicity, comorbidities, insurance status, stage, BM and extranodal involvement, treatment received, outcome at 3 and 5 years and vitality status in 2018. Continuously distributed outcomes were summarized with the mean and standard deviation and categorical outcomes were summarized with frequencies and percentages. The significance of variation in the mean with disease category was assessed with one way ANOVA and the significance of associations between categorical outcomes was assessed with Pearson's Chi Square or Fisher's Exact test as appropriate. Multivariate logistic regression was used to model binary outcomes in terms of covariates and indicators of disease. All statistical testing was two-sided with a significance level of 5%. R1 was used throughout.

The study was approved by the local Institutional Review Board. The findings will be available to patients, funders and medical community through traditional publishing and social media.

RESULTS

We identified 116 patients with HL, of which 73 were HI (63%), 43 NH (36%) and 1 not specified (1%). In regard to race, 92% identified as Caucasian, 4% as African American, 3% other and 1% Asian. The median age at diagnosis was 37.4, (SD 15.13). There were 49 females (42%) and 67 males (58%). The most common funding source was commercial insurance N=54 (47%), followed by a hospital payment plan N=30 (26%), Medicare N=16 (14%), unfunded N=13 (11%) and Medicaid N=3 (2%). Most prevalent co-morbidities were HTN N=28 (24%) and diabetes mellitus N= 23(20%); 50% of patients had no co-morbidities (N=63).At diagnosis ECOG of 0-1 was seen in 108 patients (93%); 8 were Stage I (7%), 39 stage II (33%), 32 stage III (28%), and 37 stage IV (32%). EBV was positive in 26 patients (22%). There were 15 patients that were HIV positive (13%), 54% with CD4 count <200, and 12 (75%) on antiretroviral therapy at diagnosis.

Median PFS was 853.85 days (SD 912.92). We excluded patients who were lost to follow up or had not reached 3/5 years. At 3 year follow up there was: complete response in 37 HI (74%) vs 22 NH (92%); disease progression in 8 (16%) vs 0 (0%); death in 5 (10%) vs 2 (8%), respectively (p-value= 0.094). At 5 year follow up there was: complete response in 30 HI (77%) vs 17 NH (90%); progressive disease in 2 (5%) vs 0 (0); death 7 (18%) vs 2 (11%), respectively (p-value = 0.619). At the end of 2018, 41 HI (84%) were alive compared to 22 NH (88%) [p-value 0.74].

CONCLUSION

Within the limitations of sample size, our study demonstrates that in the prevalently Hispanic population of our institution, HI patients with HL have no statistically significant difference in outcome when compared to NH patients.