Bone marrow biopsies (BMB) are often obtained from patients preparing to undergo treatment for lymphoma in clinical trials. Sometimes BMB are obtained after therapy as well to confirm complete response (CR).
But a team of researchers questioned whether those BMB were really necessary. They hypothesized that only a few patients would have positive baseline BMB, CR on imaging, and subsequent positive BMB. To investigate their hypothesis, they analyzed data from 7 clinical trials with patients with follicular lymphoma (FL). Their findings were published in the Journal of Clinical Oncology.
The researchers reviewed data from 580 patients with previously untreated FL. They found only 5 (0.8%) of those patients had positive BMB, CR on imaging, and subsequent positive BMB (P <.0001). They also found that of the 344 patients who had CR on imaging after treatment, BMB altered the response assessment in only 1.5%.
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Since confirmatory biopsies were not available for everyone, the researchers also conducted landmark survival analyses to compare progression-free survival (PFS) and overall survival (OS) in patients who had CR on imaging and negative BMB with patients with CR on imaging but without repeat BMB.
These findings establish that subsequent BMB do not affect response assessment in patients with untreated FL enrolled in clinical trials. The researchers noted that the results of a biopsy changed the response assessment in only approximately 10 patients (1%).
“The landmark survival analysis was performed to compare outcomes in [participants] who did not undergo BMB with those who did have confirmatory BMB, and we found no difference in PFS and OS,” the researchers noted. “Therefore, BMB do not enable identification of distinct PFS/OS outcomes in FL patients with positive findings at baseline.”
Although BMB may not be necessary in some circumstances, such as when patients are being followed without treatment, BMB can still be useful in patients with FL in select circumstances, such as confirmation of stage 1 disease when radiotherapy can be used in a curative attempt.
But in general, BMB do not seem to provide value, and the researchers wrote, “BMB should be eliminated from diagnostic guidelines in FL, and no longer incorporated as response assessments in clinical trials for patients with FL,” the researchers concluded.
The study was limited by its retrospective nature and response criteria variation in the National Cancer Institute National Clinical Trials Network FL clinical trials. The researchers also acknowledged that a significant number of the patients did not undergo confirmatory BMB.
According to the researchers, some patients may be discouraged from participating in clinical trials by BMB requirements. Additionally, there are the cost and pain factors to consider. Therefore, these findings could be used to encourage patients with such concerns to participate in future trials.
Disclosures: Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Reference
Rutherford SC, Yin J, Pederson L, et al. Relevance of bone marrow biopsies for response assessment in US National Cancer Institute National Clinical Trials Network follicular lymphoma clinical trials. J Clin Oncol. Published online July 5, 2022. doi:10.1200/JCO.21.02301
