Evaluating the cancer aging and research group model in predicting immunochemotherapy toxicity among elderly patients with diffuse large B-cell lymphoma

Background: The management of diffuse large B-cell lymphoma (DLBCL) in elderly patients is complicated by an increased risk of treatment-related toxicity associated with aging. This study aimed to validate the effectiveness of the Cancer Aging and Research Group (CARG) model in elderly patients with DLBCL receiving rituximab-based chemotherapy. Methods: In this prospective study, elderly DLBCL patients (aged 65 years or older) receiving rituximab-based chemotherapy were consecutively assessed between August 2016 and December 2021 at one medical center in Taiwan using the CARG model to predict treatment-related toxicity. Patients were categorized into low-, medium-, and high-risk groups based on their CARG scores. Comparisons were made regarding toxicities and survival rates among these groups. Results: Ninety-one patients, with a median age of 70 years (range 65–96), were included. A substantial 81 % (74 patients) experienced grade 3–5 toxicity. The overall 2-year survival rate was 63.8 % after a median follow-up of 28 months (range, 2–46). The risk of grade 3–5 toxicity was 83 %, 78 %, and 87 %, respectively, among the low-, medium-, and high-risk groups (p = 0.60). The receiver operating characteristic (ROC) curve for CARG was 0.521 (95 % CI, 0.376–0.666), which was significantly lower than that for the Eastern Cancer Oncology Group score (ROC = 0.701, 95 % CI, 0.571–0.831). Similarly, compared with those of low-risk patients, hazard ratios for overall survival were 9.22 (95 % CI, 1.23–69.1; p = 0.031) and 14.6 (95 % CI, 1.90–112; p = 0.010) for medium- and high-risk patients, respectively. Conclusion: While CARG exhibited limitations in predicting treatment-related toxicity in elderly DLBCL patients, it demonstrated potential efficacy in predicting survival outcomes.