Dr Arora on A Retrospective Analysis of Temporal Trends to Assess MCL Incidence From 2000-2021

"Looking at incidence, we focused on one main factor called APC, and we were able to statistically define the APC across multiple year sets [i.e., time intervals]."

Ruby Arora, MD, a resident physician of Internal Medicine in the Department of Medicine at the University of Illinois College of Medicine, discussed the design of a retrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database evaluating temporal trends in mantle cell lymphoma (MCL) incidence from 2000 to 2021. Given that MCL represents a relatively uncommon subtype of non-Hodgkin lymphoma (NHL), accounting for approximately 5% of cases, the SEER database provided the necessary sample size and longitudinal data to allow for robust statistical evaluation of changes in MCL incidence and survival rates across defined time periods, according to Arora.

The analysis used SEER data from 22 US states spanning over 2 decades to quantify annual percent change (APC) trends in incidence rates. APC was assessed across discrete 5-year intervals to determine statistically significant changes in MCL incidence over time. Arora emphasized that stratifying APC by these temporal blocks permitted a more granular and statistically meaningful assessment of evolving epidemiologic patterns.

Findings demonstrated a statistically significant decline in MCL incidence in the most recent 5-year interval compared with preceding periods, Arora said. This downward trend aligns with the broader decline observed in the overall incidence of NHL in the US during the same timeframe. The results suggest that MCL incidence may be following the general epidemiological trajectory of other NHL subtypes, although the biological or environmental factors contributing to this trend were not directly evaluated in this study.

The ability to identify statistically robust shifts in MCL incidence using SEER data strengthens the validity of the findings and supports the use of population-based registries to assess long-term epidemiologic trends in rare lymphoma subtypes.