Albumin can be raised as part of a non-specific increase in phase reactants, which can be an indicator of serious illness. But low albumin is also seen in conditions in general practice, which turns out to be cancer.
In a British study in general practice, it was found that low albumin (defined as less than 35 g / l) had a likelihood ratio for cancer of 2.2, which means that low albumin are associated with cancer.
In the single patient, low albumin have vastly different reasons, but an unexplained low albumin should make the practitioner consider cancer as a possible differential diagnosis.
Association between unexplained hypoalbuminaemia and new cancer diagnoses in UK primary care patients. Merriel SW, Carroll R, Hamilton F, Hamilton W. Family Practice, 2016