An Analysis of Rates of Discontinuation and Nonpublication in Colorectal Cancer Clinical Trials

Research output: Contribution to conferencePosterpeer-review


Background: Thousands of clinical trials are conducted every year across the world. In 2018, the National Institutes of Health — a United States government agency for biomedical and public health research subsidized by American citizen taxes — allocated over $200 million for evaluating treatments for colorectal cancer (CRC). This data provides necessary information for the advancement of pharmaceuticals and medical procedures. The nonpublication of the data from completed clinical trials poses an ethical dilemma for patients and providers. Discontinuation of trials also threatens patients as they are given potentially harmful experimental drugs or undergo procedures in which no data gets published. Here, the rates of discontinuation and nonpublication of clinical trials relating to colorectal cancer are shown in the provided tables.

Methods: We performed an advanced search on on pertaining to the treatment of CRC using the keyword colorectal cancer. We attempted to locate a publication for each registered trial by their NCT number. For each clinical trial, links to the publication provided by were searched and verified to be correct. If a publication was unable to be found using the methods above, we attempted to locate the email address of the lead investigator or sponsor listed on the website to inquire status of trial.

Results: Of the 123 (123/428, 28.7%) discontinued trials, a reason for discontinuation was provided for 49 (49/123, 39.8%) trials on and 8 (8/123, 6.5%) from email correspondence with trial authors making a total of 57 (57/123, 46.3%) reasons for discontinuation of trials found. After email correspondence, 50 (50/123, 40.7%) trials were terminated, 5 (5/123, 4.1%) were withdrawn, 2 were suspended (2/123, 1.6%), and 66 (66/123, 53.7%) were discontinued for unknown reasons. Of the 305 (305/428, 71.3%) completed trials, 244 (244/305, 80.0%) had a verifiable publication, while 61 (61/305, 20.0%) did not publish their findings or were unable to be located. Of the 244 (244/305, 80.0%), 233 (233/244, 95.5%) had provided links on or were easily searchable using research protocols highlighted above, with 11 (11/244, 4.5%) located from links provided by email correspondence with trial authors.

Conclusion: We found that over half of all results of clinical trials related to CRC did not get published. This is a problem that creates significant waste within medical research. Our study found in colorectal cancer research, nearly 1 in 3 clinical trials do not get published and 1 in 4 trials are discontinued. Not only that, but also over 1 in 5 patients were involved with clinical trials that did not publish results. More transparency is needed when it comes to clinical trials pertaining to CRC. Publication of results from both completed and discontinued RCTs can help researchers make more informed decisions. Nonpublication of clinical trials subjects patients to potentially harmful interventions while foregoing the only benefit that ensues from said interventions, which is the possibility to advance scientific research and education.
Original languageAmerican English
StatePublished - 22 Feb 2021
EventOklahoma State University Center for Health Sciences Research Days 2021: Poster presentation - Oklahoma State University Center for Health Sciences Campus, Tulsa, United States
Duration: 22 Feb 202126 Feb 2021


ConferenceOklahoma State University Center for Health Sciences Research Days 2021
Country/TerritoryUnited States


  • Colorectal Cancer
  • Clinical Trials
  • Nonpublication
  • Discontinuation


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