Bone pain from granulocyte colony stimulating factor: does clinical trial sponsorship by a pharmaceutical company influence its reporting?

It is alleged that pharmaceutical companies sometimes unfairly present clinical trial results. To our knowledge, studies have not explored whether such alleged unfair reporting also occurs in the testing of palliative care agents in cancer patients, a particularly vulnerable group. Therefore, a systematic search was conducted to retrieve all published, prospective clinical trials that used granulocyte colony stimulating factor starting in 2003. Because granulocyte colony stimulating factor can cause severe bone pain - a concerning but historically under-reported symptom in cancer patients - this symptom was assessed to determine whether differences in reporting occurred based on pharmaceutical company-sponsorship. A total of 239 published clinical trials met the present study's eligibility criteria and were retrievable. Within this entire group of studies, 65 (27%) were pharmaceutical company-sponsored, and only 31 (13%) reported on bone pain. However, pharmaceutical company-sponsored trials reported on bone pain at a higher rate compared with other studies: 23% versus 9% (P= 0.005), and this conclusion did not change after adjusting for dose, use of the slow release formulation and year of publication. The reporting of adverse events from cancer symptom control and palliative care interventions should be improved - especially in trials not sponsored by pharmaceutical companies.