Reassessing pre-chemotherapy laboratory testing in R-CHOP: Are we doing too much?

Abstract Background: Routine laboratory testing prior to chemotherapy administration is a cornerstone of hematology and oncology practice, aimed at ensuring the safety and efficacy of treatment. However, over time, standardized protocols may accumulate excessive or low-yield laboratory tests that offer limited value to clinical decision-making. In 2018, Mayo Clinic implemented standardized treatment protocols using Epic Beacon, an electronic health record module that integrates chemotherapy regimens with associated laboratory testing and clinical workflows. While well-intentioned, these protocols may include redundant tests that delay treatment initiation, increase patient discomfort and anxiety, and burden providers with excessive in-basket communications. We hypothesize that many laboratory tests currently embedded within prechemotherapy workflows are unnecessary and can be safely omitted without compromising patient care. Methods: We conducted a retrospective cohort study evaluating the pre-treatment laboratory testing associated with the R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy protocol within the Mayo Clinic Rochester Division of Hematology. The study included 100 patients diagnosed with diffuse large B-cell lymphoma who received treatment between January 1 and December 31, 2024. Patients were excluded if they had incomplete medical records or received treatment outside the Mayo Clinic system. Data was abstracted via chart review using the Mayo Data Explorer. We analyzed complete blood counts (CBC), which include 12 individual tests, and comprehensive metabolic panels (CMP), which include 16 individual tests, obtained prior to each treatment cycle. For each cycle, we assessed the proportion of abnormal laboratory results and the proportion of abnormal results deemed clinically relevant which were defined as those that prompted a treatment delay, dose reduction or early termination of a cycle. Results: The cohort comprised 100 patients with a mean age of 68.2 years (SD 13.4) and a median age of 71 years (IQR 58.75–77); 57 were male and 43 were female. Based on available documentation, disease stage was classified as limited (stage I/II; n=41) or extensive (stage III/IV; n=59). A total of 519 R-CHOP cycles were administered, including 419 subsequent cycles (cycles 2–6). Fifteen patients discontinued treatment early, although none of the discontinuations were attributable to abnormalities in pre-infusion laboratory testing. Among the 419 subsequent cycles, 34 (8.1%) experienced treatment delays, with only one delay resulting from a clinically significant laboratory abnormality (hyperglycemia). Additionally, 23 patients underwent regimen modification (dose reduction or drug holding), but none of these were due to pre-infusion lab abnormalities.Of the 411 comprehensive metabolic panels (CMPs) obtained prior to these cycles, 315 (76.6%) contained at least one abnormal value, yielding a total of 786 abnormal results. Similarly, 405 of 415 (97.6%) complete blood counts (CBCs) demonstrated at least one abnormality, generating 2,696 abnormal values in total. Despite the high frequency of abnormal findings, the overall clinical yield was minimal, with only 1 of 826 pre-infusion laboratory panels (0.12%) leading to a modification in clinical management. Conclusion: Routine pre-infusion laboratory testing prior to R-CHOP chemotherapy frequently identifies abnormal results. However, these abnormalities are rarely clinically significant and do not affect treatment decisions. These findings support the reconsideration of current testing protocols to reduce unnecessary testing, enhance workflow efficiency, and minimize patient and provider burden without compromising safety.