Early host adaptation defined by nutritional and inflammatory dynamics predicts disease progression in solid tumours

Whether inflammatory and nutritional parameters shift meaningfully in the first months of systemic treatment - and whether these shifts predict outcomes - has not been adequately addressed. We set out to track these changes from treatment initiation to month 3 in adults with newly diagnosed solid tumors, with progression-free and overall survival as primary endpoints.

This was a single-center prospective study running from August 2023 through August 2024. Patients aged ≥ 18 with histologically proven solid tumors who were about to start systemic anticancer therapy were consecutively enrolled; 100 completed both assessment points. At each visit - baseline and month 3 - we recorded anthropometric data, performed BIA for body composition, administered the MNA-SF, measured handgrip strength and gait speed, and collected fasting blood samples for biochemical analysis. Wilcoxon signed-rank test, Spearman correlation, ROC curves, and logistic regression were the main analytical tools.

No sarcopenia was detected at baseline. By month 3, only one patient (1%) had developed it. Body fat percentage dropped significantly (P = 0.019); SMI and muscle mass stayed stable. MNA scores were essentially unchanged. Third-month CRP was the only independent predictor of both progression and survival (cut-off 4.74 mg/L; AUC 0.672; P = 0.008). CRP ≥ 4.74 mg/L conferred a 3.63-fold higher progression risk on multivariate analysis (OR 3.63; 95% CI 1.34-9.85; P = 0.011). Albumin correlated with SMI at month 3 (r = 0.214; P = 0.033).

Sarcopenia was uncommon this early in the disease course. Inflammation, however, was not. Third-month CRP predicted outcomes independently - even in patients whose nutritional scores and muscle indices remained intact. This dissociation suggests inflammatory activation precedes measurable compositional decline. The positive correlation between albumin and SMI supports albumin's role as both a nutritional and functional marker. Routine CRP and albumin checks during early treatment may prove useful for identifying patients who need closer follow-up.