Increased Serum Lipase with Associated Normoamylasemia in Cancer Patients

Abstract

Measurements of the activity of both lipase (triacylglycerolacylhydrolase, EC 3.1.1.3) and α-amylase (EC 3.2.1.1) in serum are commonly used as aids in the diagnosis and follow-up of acute and recurrent pancreatitis (1); 19% of pancreatitic patients present with normal serum amylase (2), thus leaving lipase as the main hematochemical marker of this disease in a substantial number of patients. Lipase and amylase are increased also in conditions other than pancreatitis, such as several nonmalignant hepatobiliary and gastrointestinal diseases, sepsis, renal failure, pulmonary failure, and subdural bleeding (1)(2)(3)(4). In 1987, Stein et al. (5) reported on a non-Hodgkin’s lymphoma patient with major lipase activity (up to seven times the upper reference value), with no parallel increase in amylase; in this case, the authors demonstrated a specific immunoglobulin G with high affinity for lipase as the cause of increased serum lipase activity. More recently, Donnelly et al. (6) have reported a chronic increase in serum lipase, again with no associated hyperamylasemia or clinical evidence of pancreatitis, which the authors suggested to be tumor-derived; furthermore, Munoz-Perez et al. (7), after observing chronic increased serum lipase in another patient with massive abdominal metastases from a suspected pancreatic adenocarcinoma, suggested that the biochemical profile characterized by increased lipase and normal amylase could be an early finding of a malignant neoplasm. We report on four cases in which serum lipase increase first anticipated an otherwise undetectable tumor relapse or progression. Serum lipase activity was measured with a commercially available kinetic colorimetric co-lipase method (Lipase KC, Bayer Italia S.p.A., Divisione Diagnostici). Briefly, in the assay, pancreatic lipase catalyzes the hydrolysis of the 1,2-diglyceride sulfate to produce fatty acids and 2-monoglyceride. The latter, in the presence of specific auxiliary enzyme, release glycerol, which is then converted, by glycerokinase, into glycerol-3-phosphate and …