Less provider experience with rituximab may increase the likelihood of early treatment discontinuation in Medicare beneficiaries with non-Hodgkin lymphoma (NHL), according to a new study published in the Journal of the National Comprehensive Cancer Network. 

The complexities of many cancer treatments can affect delivery and outcomes in care settings. Because of the established association between volume of care provided and clinical outcomes, “it is plausible that the quality of cancer care could also be better for patients receiving complex systemic therapies at the hands of medical oncologists who have greater experience with those agents,” the researchers wrote.

The study aimed to evaluate the association between physician-level experience and cancer treatment outcomes. Researchers conducted a population-based study of adults aged 66 years and older who were diagnosed with B-cell NHL from 2004 through 2011 using SEER-Medicare data. Approximately half of the cohort had advanced-stage disease at diagnosis and most initiated rituximab alongside chemotherapy.

Using these data, the researchers analyzed outcomes in patients receiving rituximab.

Rituximab, the first FDA-approved targeted monoclonal antibody for cancer, has been shown to provide clinical benefit in numerous lymphoma settings. However, its adverse effect profile differs from standard chemotherapies, with a high rate of infusion-related reactions (IRRs) occurring during the first 2 exposures, according to the researchers. As a result, physicians with less experience prescribing rituximab may be less familiar with managing these IRRs in their patients, they wrote.

Among the 15,110 patients who initiated rituximab with 2684 physicians, 7.6% experienced early rituximab discontinuation, according to the study. Approximately one-fourth of patients started rituximab therapy with a physician who had no rituximab initiations during the preceding 12 months.

Additionally, compared with patients treated by physicians who had 3 or more 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% CCI, 1.35-1.82; P<0.001 for 0 vs ≥3, and aRR, 1.19; 95% CI, 1.03-1.37; P=.02 for 1-2 vs ≥3).

The study also showed that rituximab discontinuation was associated with a higher risk of death (adjusted hazard ratio, 1.39; 95% CI, 1.28-1.52; P>.001).

Other factors associated with early discontinuation were advanced age, CLL histology, limited-stage disease, higher comorbidity score, Medicaid dual coverage, and disability.

“Given the increasing number of newer anticancer therapies with unique and potentially life-threatening adverse effects, future studies should explore the impact of physician-level volume on therapeutic clinical outcomes,” the researchers concluded.

Reference
Huntington SF, Hoag JR, Wang R, et al. Physician experience and risk of rituximab discontinuation in older adults with non-Hodgkin’s lymphoma. Journal of the National Comprehensive Cancer Network. 2019. Doi: https://doi.org/10.6004/jnccn.2019.7314