Using the cancer aging and research group- breast cancer (CARG-BC) predictive model in older adults (OA) with early breast cancer: an external validation study
摘要
Decision-making for chemotherapy in early breast cancer (EBC) in OA (older adults: age ≥ 65 years) is complex due to frailty, multimorbidity, and competing risks for mortality. Magnuson (2021) developed a chemotherapy toxicity prediction score, CARG-BC; its external validation can improve generalizability.
ObjectivesCARG-BC’s ability to predict grade 3 + chemotoxicity in OA with EBC (primary), unplanned healthcare use, and changes to chemotherapy protocol (secondary).
MethodsA single center retrospective cohort study comprising OA with EBC who received (neo) adjuvant chemotherapy from 2013–2023. Clinical, demographic, CARG-BC, and healthcare usage variables were extracted from patient records. Risk groups based on CARG-BC score were compared using T-test (continuous variables) & χ2 test (categorical variables). Toxicity risk based on CARG-BC score was assessed using logistic regression. The predictive ability of the CARG-BC score was evaluated by calculating AUC.
ResultsOf 243 patients, the median age was 70 years (range 65–86), 99.6% female, 80.2% with comorbidities, 33.7% with polypharmacy, 28.8% living alone, and 8.2% seen in the geriatric oncology clinic. Over half (53.9%) had grade 3 + toxicities. Healthcare utilization included 19.8% of patients with at least one unplanned clinic visit, 29.6% an emergency care visit, and 14.4% a hospitalization. The median CARG-BC score was 7 (IQR 3, 8) and the CARG-BC AUC was 0.76 (95% Confidence interval [CI] 0.70, 0.82). The odds of grade 3 + toxicity is increased by 1.33 times per CARG-BC point increase.
ConclusionThe CARG-BC model retained good discrimination for grade ≥ 3 chemotoxicity and should be used in shared-decision-making with OA.