Hypertrophic pulmonary osteoarthropathy with primary lung cancer

Hypertrophic pulmonary osteoarthropathy (HPO) is a rare paraneoplastic syndrome that is frequently associated with lung cancer; however, the incidence of clinically apparent HPO is not well known. The clinical data of 6,151 patients with advanced lung cancer between January 1996 and December 2008 were retrospectively analyzed in Zhejiang Cancer Hospital (Hangzhou, China). Data pertaining to the presentation of HPO, diagnosis, treatment, pathology, follow-up and clinical course were documented. HPO was confirmed using bone scintigraphy by the identification of symmetrical, abnormally high uptake in the joints, and/or long bones with digital clubbing in the extremities as well as joint pain. The clinical characteristics were investigated based on clinical and pathological records. The patients were presenting with lung cancer for the first time and had not received treatment. Among the 6,151 lung cancer patients, 115 (1.87%) demonstrated an abnormally high uptake on bone scintigraphy and digital clubbing in the extremities combined with joint pain. A total of 109 patients received surgery or chemotherapy treatment and 92 exhibited improved symptoms. The improvement rate of HPO was lower in the non-surgery compared with the surgery patients (77.4 vs. 91.1%; P=0.049). Bone scintigraphy was repeated in 85 patients within 3-6 months, and the HPO symptoms improved in 70 patients. The present retrospective study indicated that 1.87% of patients with lung cancer showed characteristics that were identified as HPO. The majority of the patient symptoms and the bone scintigram of HPO improved as a result of treatment.