Evaluating Evolution of Incidence Rates of Hodgkin Lymphoma Subtypes

the Cancer Therapy Advisor take:

Recent declines in nodular sclerosis (NS) rates represented true incidence changes, whereas long-term rate decreases for mixed cellularity (MC) and increases for non-otherwise specified (NOS) Hodgkin lymphoma (HL) were attributed to evolutions in diagnostic and/or classification practices, according to an article published online in the journal Cancer Epidemiology, Biomarkers & Prevention.

In this study, the investigators analyzed detailed histology-specific HL incidence rates from 1992 through 2011 using U.S. SEER data (n=21,372) and NOS pathology reports (regional subset from 2007-2011) for insight into diagnostic and classification practices.

Results showed cHL rates that were previously stable decreased after 2007 for whites [annual percent change (APC) and 95% CI: -3.6% (-5.6%, -1.5%)]. Similarly, a decline was observed in NS rates after 2007 by 5.9% annually, varying by gender, age, and race/ethnicity.

Furthermore, between 1992 and 2011, the overall incidence rates for MC and NOS declined (APC -4.0% [-4.7%, -3.3%]) and rose (5.3% [4.5%, 6.2%]), respectively.

There was minimal observation of trends in combined rates, suggesting increasing misclassification of MC, LD, and specific NS subtypes as NOS.

Out of 165 reviewed NOS pathology reports, 88 addressed classification choice. From these 88, 20 (12.1%) justified the classification, 21 (12.7%) had insufficient biopsy material, and 27 (16.4%) reported coders missed specific subtype information.