Stage redistribution and survival among Medicare beneficiaries before and after the approval of positron emission tomography scan for non-Hodgkin lymphoma

Recent survival trends in diffuse large B-cell lymphoma--Have we made any progress beyond rituximab?

Background

Population‐based studies previously showed an improvement in overall survival (OS) for patients with diffuse large B‐cell lymphoma (DLBCL) who received chemoimmunotherapy with rituximab. However, there is limited data (especially at the population level) that show a similar trend in OS improvement, in the most recent time period. We hypothesized that survival for DLBCL patients diagnosed in the United States has continued to improve in recent years and intended to measure outcome improvements.

Methods

Using the SEER‐18 registries, we compared the incidence and relative survival rates (RSRs) of DLBCL patients between 2002‐2007 and 2008‐2013 (availability of novel agents, broader use of autologous hematopoietic cell transplantation and improvement in supportive care). Multivariable Cox regression models were used to assess associations between the year of diagnosis and OS while controlling for age, gender, stage, and ethnicity.

Results

There were a total of 53 439 patients with DLBCL who were diagnosed between 2002 and 2013. Of these, 25 810 were diagnosed during time period‐1 and 27 629 diagnosed during time period‐2. There was a slight decline in incidence of DLBCL (time period‐1 vs time period‐2), 7.75 (95% CI = 7.66‐7.84) vs 7.43 (95% CI = 7.34‐7.52) cases per 100 000 persons, respectively (P < .0001). Overall, there was a modest improvement in DLBCL RSRs, with 5‐year RSR improving from 61% (time period‐1) to 64% (time period‐2) and the improvement was noted across all subsets of patients. On multivariable analysis, patients diagnosed in time period‐2 had lower mortality relative to time period‐1 (HR = 0.87, 95% CI = 0.85‐0.89).

Conclusions

Our study shows an improvement in the outcomes of DLBCL patients beyond the introduction of rituximab, although the magnitude of improvement is small. It will be interesting to see the impact of chimeric antigen receptor‐T cell therapy translating to population‐level survival in the next 5 years.

Changes in dynamics of excess mortality rates and net survival after diagnosis of follicular lymphoma or diffuse large B-cell lymphoma: comparison between European population-based data (EUROCARE-5)

BACKGROUND

Since 2001, the World Health Organization classification of tumours of haematopoietic and lymphoid tissues and the International Classification of Diseases for Oncology (third edition) have improved data collection for lymphoma subtypes in most European cancer registries and allowed reporting on the major non-Hodgkin lymphoma subtypes. Treatment of non-Hodgkin lymphoma has changed profoundly, benefiting patients with follicular lymphoma or diffuse large B-cell lymphoma. We aimed to compare dynamics of cancer mortality in patients with follicular lymphoma or diffuse large B-cell lymphoma in five large European areas using data for survival from the largest number of collaborative European population-based cancer registries (EUROCARE).

METHODS

We considered follicular lymphoma and diffuse large B-cell lymphoma cases in patients aged older than 15 years diagnosed between Jan 1, 1996, and Dec 31, 2004, and recorded in 43 cancer registries in five areas: Scotland and Wales, and northern, central, eastern, and southern Europe. We excluded cases incidentally diagnosed at autopsy or known from death certificates only. The vital status could be updated on Dec 31, 2008, in all registries but the French ones (Dec 31, 2007). We obtained changes in net survival with the Pohar-Perme estimator and excess mortality rate with a flexible parametric model according to age and year of diagnosis.

FINDINGS

We identified 13,988 follicular lymphoma and 25,320 diffuse large B-cell lymphoma cases. We noted improvements in 5-year net survival for all ages between the 1999-2001 and 2002-04 periods for both cancers (except for follicular lymphoma in Scotland and Wales and diffuse large B-cell lymphoma in eastern Europe). For follicular lymphoma, 5-year net survival in northern Europe was 64% (95% CI 58-71) in 1999-2001 versus 75% (69-80) for 2002-04, for Scotland and Wales, it was 71% (66-76) versus 68% (64-72), for central Europe, it was 64% (61-67) versus 72% (70-75), for southern Europe, it was 67% (63-70) versus 73% (70-76), and for eastern Europe, it was 50% (43-57) versus 61% (54-69). For diffuse large B-cell lymphoma, 5-year net survival in northern Europe was 41% (35-49) versus 58% (54-62), in Scotland and Wales, it was 44% (41-48) versus 52% (49-54), in central Europe, it was 46% (44-47) versus 50% (48-51), in southern Europe, it was 44% (42-47) versus 50% (48-52), and in eastern Europe, it was 47% (41-54) versus 46% (43-50). We noted the largest area disparity during the 2002-04 period between eastern and northern Europe. We noted a significant effect of the year of diagnosis on the excess mortality rate for all ages in all areas, except for diffuse large B-cell lymphoma in eastern Europe. The excess mortality rate was not constant during the follow-up period: we noted a high rate early for both lymphomas, except for follicular lymphoma in northern Europe.

INTERPRETATION

Although survival for follicular lymphoma and diffuse large B-cell lymphoma is improving, the results from this study should foster the search for more and better means of improvement of access to adequate care than that at present, as there remains variation in survival between European regions. Study of the dynamics of the excess mortality rate seems to be a useful clinical indicator to help the practitioner's choice of optimum management of patients.

FUNDING

Compagnia di San Paolo, Fondazione Cariplo Italy, Italian Ministry of Health, European Commission, Registre des Hémopathies Malignes de Côte d'Or, and French Agence Nationale de la Recherche.