Many investigators fail to publish the results of clinical trials in a timely fashion, exposing patients to dangers, said Spanish researchers in a presentation at the recent European Society for Radiotherapy and Oncology meeting (ESTRO 2016).
In the U.S., regulators insist that investigators publish the results of clinical trials within a year of completion, and this has been mandatory since 2007. But a new survey shows that of more than 800 trials with a primary completion date before January 2013, more than 80% of investigators had not even published summary results within a year.
"Millions of volunteers have participated in clinical trials to help find out more about the effects of treatments on disease, yet the important ethical issue of reporting results has been ignored widely," noted study authors Jaime Pérez-Alija and Pedro Gallego, medical physicists from the radiotherapy and oncology department at Hospital Plató in Barcelona.
Required, not completed
Examining 802 radiotherapy trials completed on or before January 2013, the researchers found that 655, or 81.7%, had not even published summary results within a year of completion. The group also looked at radiotherapy trials that began before the 2007 act was passed, and found little had changed. Among the earlier trials, 422 out of 552, or 76.4%, did not provide their results to the ClinicalTrials.gov database.
One possible reason for delay, the researcher said, is some trials are granted a deadline extension. But it's impossible to know which trials were extended as it seems the registry update is not occurring regularly.
Breaking down the results by cancer subtype, the team found eye cancer was the only subtype where more than half of trial results were published on time. In contrast, 100% of the testicular and anal cancer trials remained unpublished. Breast cancer went unpublished 78% of the time; lung cancer 73%, the group wrote.
"We have shown that a large number of study participants are routinely exposed to the risks of trial participation without the benefits that sharing and publishing results would have for patients in the future. This ethical issue should be at the heart of our current medical practice, and our leaders should be made aware that withholding these data poses a significant threat to public health," the authors wrote.
New steps needed
With new laws, both the U.S. and the European Union (EU) have taken steps to correct the situation. But if most trials -- even those funded by public institutions -- do not comply with these requirements, further measures will be needed.
The U.S. act allows for economic sanctions against trial sponsors who do not comply with the rules. However, enforcing the sanctions risks having some investigators decide not to start a trial, which would damage the health system and potentially patients.
One potential solution would be to institute a system that requires investigators applying for public funding to disclose results of all previous trials. The same would be required for privately funded trials, the team wrote.
ESTRO President Dr. Philip Poortmans said patients who agree to participate in trials "do so for the unselfish reason that they want to help others to have the best possible treatment in the future. Not to publish results is unfair to them, to future patients, and to medicine as a whole."
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
