Background
Systemic inflammation has prognostic value in cancer and is considered aetiological of cachexia by the Global Leadership Initiative on Malnutrition (GLIM). Lactate dehydrogenase (LDH) also has recognized prognostic value. The present study aimed to evaluate the ability of a laboratory cachexia score (LCAS) defined by LDH, CRP and albumin, to identify cachexia and predict outcome in advanced lung cancer.

Methods
Patients (n = 261) with serum LDH, CRP and albumin measurement receiving palliative radiotherapy for advanced lung cancer between 2009 and 2015 were identified. Subjects were stratified by LDH and LCAS. This was compared to GRIm and LIPI, two previously described LDH based prognostic scores, which do not incorporate CRP.

Results
On follow up there were 201 deaths. LDH and LCAS were associated with 1-year survival independent of ECOG-PS, MUST, weight loss, BMI, SMI, SMD, metastases, mGPS or NLR (all p < 0.001). On multivariate analysis LCAS (1.36, 1.13–1.63, p = 0.001), LIPI (1.50, 1.17–1.92, p = 0.02), metastases (1.53, 1.15–2.04, p = 0.004) and ECOG-PS (1.28, 1.04–1.57, p = 0.019) were independently associated with poorer overall survival.

Conclusion
LCAS appears to identify cachexia and stratify survival. This may represent a useful aetiological criterion within the GLIM framework and a more powerful prognostic tool than the phenotypic criteria.