Financial conflicts of interest are not being declared by the authors of oncology clinical drug trials published in major medical journals, US figures reveal.

One in three authors of clinical trials used as a basis for FDA registration of oncology drugs did not declare financial payments from pharmaceutical sponsors, an analysis published in JAMA shows.

In a review of declarations of interest made by 344 US-based oncologist authors in 43 published trials in 2016 and 2017, researchers found that 110 (32%) of the authors had not fully disclosed industry payments such as speaker fees, honoraria and travel expenses.

Payments declared by authors in top journals such as The Lancet and NEJM were cross checked against the payments that are required by the Physician Payments Sunshine Act of  2010 to be notified to the Open Payments Database.

The median value of general payments to oncologist authors was US$2828, with some authors receiving up to US$20,000 from pharma sponsors. Pharma payments for research averaged US$164 644 and were as high as half a million dollars. The analysis did not include payments from pharma companies for  ‘wining and dining’ hospitality.

The journals with the highest rates of undisclosed payments were The Lancet (26 of 70 authors; 37%) and NEJM (46 of 100 authors; 46%). Oncologists publishing in these two journals also had the highest percentages of undisclosed dollars received (The Lancet, 49%; NEJM 45%).

The researchers who conducted the payments analysis noted that one in four oncologist authors did not receive any pharmaceutical sponsorship, “which indicates that abstaining from industry payments during a clinical trial is possible.”

They said the failure by oncologists to declare financial conflicts of interest would add to widespread concerns that the pharmaceutical industry’s financial relationships with medical practitioners unduly influences professional behaviour and judgement.

“In clinical trials of FDA-approved oncology drugs, bias, either real or potential, is more concerning because these oncology drugs are often associated with marginal improvement in survival but exorbitant costs,” they added.