Comparative assessment of primary and paraneoplastic gout in lung cancer

Abstract

Introduction. Lung cancer (LС) is the most common cause of the so-called paraneoplastic syndrome (PNPS) development, caused by the complex immunoinflammatory, degenerative and vascular distant changes. The risk of LC development is increased in patients with gout which proves the connection between violations of purine metabolism and carcinogenesis. Paraneoplastic (neoplastic) gout is one of the relatively frequent manifestations of LC, but such a relationship of the diseases requires further study. The objective of the study: to compare the clinical and laboratory course of primary gout and disease in the LC patients compared with the tumor process clinical course in the other signs of PNPS presence and to identify risk factors. Materials and methods. 113 patients with gout (97 men and 16 women aged 33 to 79 years) were observed. They were divided into two groups: the first group consisted of 54 patients with primary gout and the second group consisted of 59 patients with paraneoplastic variant of LC. Whereas in the 1st group the ratio of men and women was 26:1, in the 2nd – only 3: 1, and the average age was 50 and 59 years, respectively. The clinical course of gout and tumor process in the 2nd (main) group was compared with that in 199 LC patients with PNPS (comparison group), which was diagnosed in 15.5 % of LC observations. Purine metabolism was assessed by blood levels of uric acid and oxypurinol, their renal clearance, serum activity of xanthine oxidase, xanthine deaminase, adenosine deaminase, and 5-nucleotidase. Results. Paraneoplastic (neoplastic) gout develops in 3.5 % of the LC patients and in 22.9 % of those with PNPS. It differs from the primary (idiopathic) gout by the greater frequency of the disease development in women, the hand joints involvement and the metabolic type of hyperuricemia, but less often observed urolithiasis, peripheral tophi, chronic form of arthritis and the absence of renal type of purine metabolism impairment. Patients with tumorous gout differ from other LC patients with PNPS by the absence of bilateral and median lobe localization of the lung process, but relatively frequent occurrence of Pancoast tumor, high levels of uric acid and xanthine oxidase in the blood. The development of paraneoplastic gout depends on the clinical course of the LC (tumor invasion into the thoracic wall and pericardium, the number of distant organs metastasis) and the power of chemotherapy, the use of alkylating antineoplastic agents and alkaloids. Treatment-associated myelodepression, radiation pneumofibrosis and acute thrombophlebitis development depends on paraneoplastic gout. The presence of gout does not worsen the survival of LC patients with PNPS. LC patients with hyperuricemia (> 420 μmol / l in men and > 360 μmol / L in women) should be prescribed with xanthine oxidase inhibitor - allopurinol in the complex of therapeutic measures. Conclusions . Paraneoplastic gout is a frequent PNPS manifestation in LC, its course has peculiarities compared with the primary gout and is closely related to the tumor process character and the power of chemotherapy, it can determine the complications development in the course of therapeutic interventions. The data presented in the study require further comparative analysis of the other signs of PNPS, comparison of tumor and idiopathic variants of the musculoskeletal system lesion, cutaneous vasculitis and autoimmune systemic syndromes, which might assist in developing of the additional prognostic criteria for the tumor process clinical course, increasing the efficiency of therapy and its control quality.