Long-term survival in young and middle-aged Hodgkin lymphoma patients in Sweden 1992-2009-trends in cure proportions by clinical characteristics

Abstract

Trends in Hodgkin lymphoma (HL) survival among patients treated outside of clinical trials provide real-world benchmark estimates of prognosis and help identify patient subgroups for targeted trials. In a Swedish population-based cohort of 1947 HL patients diagnosed in 1992-2009 at ages 18-59 years, we estimated relative survival (RS), cure proportions (CP), and median survival times using flexible parametric cure models. Overall, the CP was 89% (95% CI: 0.87-0.91) and median survival of the uncured was 4.6 years (95% CI: 3.0-6.3). For patients aged 18-50 years diagnosed after the year 2000, CP was high and stable, whereas for patients of 50-59 years, cure was not reached. The survival of relapse-free patients was similar to that of the general population (RS5-year : 0.99; 95% CI: 0.98-0.99, RS15-year : 0.95; 95% CI: 0.92-0.97). The excess mortality of relapsing patients was 19 times (95% CI: 12-31) that of relapse-free patients. Despite modern treatments, patients with adverse prognostic factors (e.g., advanced stage) still had markedly worse outcomes [CP stage: IIIB 0.82 (95% CI: 0.73-0.89); CP stage: IVB 0.72, (95% CI: 0.60-0.81)] and patients with international prognostic score (IPS) ≥3 had 2.7 times higher excess mortality (95% CI: 1.0-7.0, p = 0.04) than patients with IPS <3. High-risk patients selected for 6-8 courses of BEACOPP (bleomycin, etoposide, doxorubicin, cyclofosphamide, vincristine, procarbazine, prednisone)-chemotherapy had a 15-year relative survival of 87%, (95% CI: 0.80-0.92), whereas the corresponding estimate for patients selected for 6-8 courses of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) was 93% (95% CI: 0.88-0.97). These population-based results indicate limited fatal side-effects in the 15-year perspective with contemporary treatments, while the unmet need of effective relapse treatment remains of concern. BEACOPP-chemotherapy was still not sufficient in high-risk HL patients.