Prognostic Value of Prospective Longitudinal CRP to Albumin Ratio among Older Outpatients with Cancer

SIMPLE SUMMARY: The prognostic value of the C-reactive protein to albumin ratio (CAR) among older adults with cancer is not known. As an inflammation and nutrition-based score, the CAR could be used as a biomarker of cancer-cachexia. We aimed to assess the prognostic value of longitudinal trajectories of the CAR on overall survival among older adults with cancer. By identifying two distinct clusters in the longitudinal trajectories of the CAR with significantly different overall survivals, we were able to characterize older patients with cancer which are the most at-risk to have a cancer-cachexia trajectory. For these patients (typically the most frail with a metastatic cancer), we suggest an early assessment of muscle mass in order to start a multimodal rehabilitation as soon as possible. ABSTRACT: The prognostic value of the CRP to albumin ratio (CAR) among older adults with cancer is not known. Six hundred and three older outpatients with cancer and undergoing geriatric assessment before therapeutic decisions were prospectively recruited from the PF-EC cohort study. Serum albumin levels, serum CRP levels and the CAR were prospectively recorded at baseline, and at each consultation thereafter, as follows: 1, 3, 6, 9, 12, 18, 24 and 36 months. Frailty was defined as a G8-index ≤ 14. The primary endpoint was longitudinal variation in the CAR during the study follow-up. Two clusters in the longitudinal trajectories of the CAR were identified, one favourable, with lower values and better overall survival (cluster A), and the second with higher values and less favourable overall survival (cluster B). The median CAR [95% CI] for clusters A and B were respectively: 0.17 [0.04–0.48] and 0.26 [0.04–0.79] at baseline (p = 0.01), and 0.18 [0.02–3.17] and 0.76 [0.03–6.87] during the study follow-up (p < 0.0001). Cluster B was associated with the frailest patients with metastatic disease, mainly driven by a high CRP level at baseline, and low albumin during the study follow-up. Our study results suggest that the most risk-prone patients have a cancer-cachexia trajectory.