Oncologist Experience With Rituximab Factors Into Early Discontinuation Rate

The less experience an oncologist has with administering rituximab, the more likely a Medicare beneficiary with non-Hodgkin lymphoma (NHL) is to discontinue treatment, according to a new study. In addition, early rituximab discontinuation was associated with inferior lymphoma-specific and overall survival.

In many complex healthcare settings, provider experience, or clinical volume, is linked with improved outcomes. This report, published in the Journal of the National Comprehensive Cancer Network, indicates a similar finding for high-quality cancer care.

Even as anticancer therapies become more complex, the researchers wrote, studies looking at physician-level experience and cancer treatment outcomes are lacking.

This population-based study involved adults 66 years or older diagnosed with B-cell NHL in 2004 through 2011 to see how the level of physician experience using rituximab and managing its infusion-related reactions would be associated with ending treatment early.

The authors chose rituximab to study because, while it is successful against lymphomas, its adverse effect profile differs from standard chemotherapies; infusion-related reactions (IRRs) occur in more than 50% of patients during the first 2 exposures, a rate significantly higher than for biologics that came after rituximab for solid tumors. Although most IRRs can be managed, they are occasionally life threatening.

Using SEER-Medicare data, a 12-month review of each initiation of rituximab was used to categorize physician volume (0, 1-2, or 3 or more initiations per year). Modified Poisson regression was used to account for provider-level correlation and estimated relative risk (RR) of early rituximab discontinuation, which was defined as fewer than 3 cycles within 180 days of starting therapy. Cox proportional hazards were used to measure the impact of rituximab discontinuation on survival.

Of the 15,110 patients who began rituximab with 2684 physicians, 7.6% experienced early rituximab discontinuation. A little more than one-fourth of patients (26.1%) initiated rituximab with a physician who had no rituximab initiations during the preceding 12 months. Compared with patients treated by physicians who had 3 or rituximab initiations in the prior year, those treated by physicians without initiations were 57% more likely to experience early discontinuation (adjusted RR [aRR], 1.57; 95%, 1.35-1.82; P <.001 for 0 vs ≥3; and aRR, 1.19; 95% CI, 1.03-1.37; P = .02 for 1-2 vs ≥3).

Additionally, rituximab discontinuation was associated with higher risk of death (adjusted hazard ratio, 1.39; 95% CI, 1.28-1.52; P <.001).

Reference

Huntington SF, Hoag JR, Wang R, et al. Physician experience and risk of rituximab discontinuation in older adults with Non-Hodgkin’s lymphoma. J Natl Compr Canc Netw. 2019;17(10) doi: 10.6004/jnccn.2019.7314.