Predictive ability of the Cancer and Aging Research Group chemotherapy toxicity calculator in hematologic malignancy

Introduction

Chemotherapy toxicity tools are rarely studied in patients with hematologic malignancy (HM). The primary aim of this pilot study was to determine the predictive ability of the Cancer and Aging Research Group (CARG) chemo-toxicity calculator in estimating grade 3–5 toxicity in patients with HM.

Materials and Methods

Patients 60 years and older with HM were prospectively evaluated using the CARG chemo-toxicity calculator. Discrimination and calibration were checked by applying the published model in our data. Additionally, a full geriatric assessment (GA), the Short Physical Performance Battery (SPPB), and health related quality of life (HRQoL) were captured longitudinally at the start of treatment and at end of study. Secondary aims explored the association of GA metrics with chemo-related toxicities and survival.

Results

One hundred forty-five patients were approached, 118 patients consented, and 97 patients were evaluable. Most patients were newly diagnosed (n = 91). The median CARG score was 9 (range 4–18). The CARG score was not validated in our cohort of older patients with HM, with area under the receiver operation characteristic curve being 0.53 (95 % CI: 0.41–0.65). In multivariable analysis, after controlling for disease type, risk factors associated with grade 3–5 toxicity included living alone (hazard ratio [HR] 4.24, 95 %CI: 2.07–8.68, p < 0.001), increase in body mass index (HR 1.06, 95 %CI: 1.01–1.12, p = 0.03) and a higher social activities score (HR 1.27, 95 %CI: 1.06–1.51, p = 0.01). In multivariable analysis of overall survival, the only prognostic factor was an objective marker of physical function (SPPB score HR = 0.85, 95 %CI:0.78–0.93, p < 0.001).

Discussion

The CARG chemo-toxicity calculator was not predictive of grade 3–5 toxicity in patients with hematologic malignancy. The SPPB was associated with overall survival in multivariable analysis, suggesting future use as an objective biomarker in HM. We also report a comprehensive trajectory of function, QoL, psychosocial well-being, and cognition among older adults with HM. The predictive accuracy of the CARG chemo-toxicity calculator may be affected by the diverse range of HM treatment options that are not traditional chemotherapy.