Review of current therapies for secondary hypertrophic pulmonary osteoarthropathy.

Hypertrophic osteoarthropathy (HOA) is a disabling condition that may occur secondarily to primary lung cancer. It is characterized by digital clubbing, arthralgia/arthritis, and periostosis of the tubular bones. The pain associated with HOA can be disabling and often refractory to conventional analgesics. We performed a comprehensive review of the literature using the PubMed database on treatment modalities available for HOA. We found 52 relevant articles-40 case reports, six case series, two review papers, and four combined case series and review papers. There were no randomized controlled trials reported. We then classified treatments used for HOA into two categories: (1) treatment of primary cause (i.e., resection of tumor, chemotherapy, radiotherapy, treatment of infection, etc.) and (2) symptomatic treatments (i.e., bisphosphonates, octreotide, NSAIDs, vagotomy, etc.). Subsequently, we summarized the main findings for each treatment. Although the clinical diagnosis of HOA has existed for over 100 years, the pathogenesis mechanism has not yet been elucidated, and treatment options for this condition remain experimental. Primary treatment is the most widely reported modality to be efficacious. In cases which primary therapy is not possible, several symptomatic treatment modalities are suggested, with various degree of success. Further research is needed to clarify the pathophysiological mechanism of HOA as to appropriately direct therapy.