Circulating procalcitonin in aseptic carcinoma patients: a specificity study with (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography as benchmark.

Background: The goal of the study was to evaluate the specificity of serum procalcitonin (PCT) in a large cohort of patients with solid carcinomas at different stages.

Methods: The study involved 447 patients having histologically confirmed carcinoma of the breast, head and neck, ovary, cervix or non-small cell lung carcinoma. Patients with a history of small cell lung cancer, neuroendocrine tumors, medullary thyroid carcinoma, sepsis, systemic inflammatory syndrome, renal failure and/or serum C-reactive protein above 5 ng/mL were excluded. Additionally, those with suspicious infectious or inflammatory diseases in (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography were also excluded. Serum PCT concentrations were measured using a Kryptor system (BRAHMS) and a clinical cut-off at 0.5 ng/mL was used to define positive results.

Results: Serum PCT concentrations did not change at different cancer stages (Kruskal-Wallis, p>0.05). No patient had a PCT concentration >0.5 ng/mL.

Conclusions: Our data show that solid carcinomas "per se" did not increase circulating PCT concentrations, regardless of the histotype and stage of the disease.