Circulating Free RNA as a Therapeutic Evaluation in Diffuse Large B-cell Lymphoma: A Case Series from the Indonesian Cancer Center.

Cancer is still the leading cause of death worldwide. Despite advances in diagnosis, management with the rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone (R-CHOP) chemotherapy regimen, and careful clinical and radiologic evaluation, diffuse large B-cell lymphoma (DLBCL) still carries high recurrence in clinical practice. This case series aims to assess the potential of circulating free RNA as a biomarker for evaluating therapeutic responses in DLBCL. This case series was conducted at Dharmais National Cancer Center Hospital in Jakarta in 2020. The subjects were 13 DLBCL patients who came for treatment to our hospital in 2020. Sampling was carried out by taking peripheral blood, which was taken 7-14 days after the patient underwent the 3rd and 6th cycles of chemotherapy or before and 7-14 days following the 3rd cycle of chemotherapy. Circulating free RNA (cfRNA) was extracted and assessed. The quantity of cfRNA was subsequently examined twice as matching samples from each patient, with the following results - (1) no mutations detected; (2) mutation detected solely in the second examination; (3) mutation only detected in the first examination; and (4) changes in gene mutations and mutation types. Statistic tabulation neither showed an association between recurrency and clinical variables nor detected cfRNA from the matching samples. This case series underscores the challenges in utilizing cfRNA as a biomarker for therapeutic evaluation in DLBCL due to heterogeneity and increased mutations in post chemotherapy conditions. Further research with larger sample sizes is needed to emphasize the role of cfRNA in DLBCL disease monitoring.