In a pooled analysis of patients with follicular lymphoma treated in National Clinical Trials Network trials reported in the Journal of Clinical Oncology, Rutherford et al found evidence that bone marrow biopsies can be avoided in response assessment.
The investigators stated, “Bone marrow biopsies are performed before/after therapy to confirm complete response in patients with lymphoma on clinical trials. We sought to establish whether bone marrow biopsies add value in assessing response or predict progression-free survival or overall survival outcomes in follicular lymphoma….”
The analysis included a pooled population of 580 previously untreated patients with follicular lymphoma from seven Alliance and SWOG trials that completed enrollment between 2008 and 2016. A sensitivity analysis (including 385 patients treated in an ECOG study) was also performed.
Among the 580 patients in the Alliance/SWOG cohort, 5 (0.9%) had positive baseline bone marrow biopsies, complete response on imaging, and subsequent positive bone marrow biopsies (P < .0001 vs null hypothesis of ≥ 10%); as stated by the investigators, this finding indicates that bone marrow biopsy was irrelevant to response in 99% of patients. Among 344 patients with complete response on imaging after treatment, 5 (1.5%) had bone marrow biopsies that altered response assessment. In the sensitivity analysis in the ECOG cohort, 5 (1.3%) of 385 patients had bone marrow biopsies that affected response assessment.
To account for the fact that some patients do not undergo confirmatory bone marrow biopsies, a landmark survival analysis from first radiologic complete response was performed among patients with positive baseline bone marrow biopsies in the Alliance/SWOG cohort. Among 187 patients with complete response on imaging, no significant differences between 47 with negative bone marrow biopsies to confirm response vs 140 with no repeat bone marrow biopsy were observed in progression-free survival (adjusted hazard ratio [HR] = 1.10, 95% confidence interval [CI] = 0.62–1.94, P = .686) or overall survival (HR = 0.59, 95% CI = 0.23–1.53, P = .276).
The investigators stated, “We conclude that bone marrow biopsies add little value to response assessment in subjects with follicular lymphoma treated on clinical trials and we recommend eliminating bone marrow biopsies from clinical trial requirements. Bone marrow biopsies should also be removed from diagnostic guidelines for follicular lymphoma except in scenarios in which it may change management, including confirmation of limited stage and assessment of cytopenias. This would reduce cost, patient discomfort, resource utilization, and potentially remove a barrier to trial enrollment.”
Sarah C. Rutherford, MD, of Weill Cornell Medicine and NewYork-Presbyterian Hospital, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Cancer Institute and in part by Celgene and GSK. For full disclosures of the study authors, visit ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.