In academic publishing, papers may be retracted when errors, research misconduct, or problems with the publication process undermine confidence in their findings. As more research is published, the number of retractions has also increased, with cases involving data manipulation, image fabrication, and manipulation of the peer review process becoming more prominent alongside plagiarism and duplicate publication.
To investigate trends in retracted research on brain and central nervous system (CNS) tumors, a study published in Volume 12 of the Chinese Neurosurgical Journal on August 10, 2026, analyzed retracted papers in this field.
The study found that retractions have increased over time, with China, the United States, and India accounting for the highest numbers of retracted papers based on the first author's country. More concerningly, nearly 90% of the cited papers continued to receive citations after retraction, raising concerns about the continued use of unreliable research in this field. The study was conducted by researchers from Beijing Tiantan Hospital, Capital Medical University China.
"Given the rising trend of retractions in biomedical research and the absence of systematic data for CNS tumor retractions, this study was conducted to characterize the landscape of retracted publications and inform efforts to maintain research integrity in neuro-oncology," the study notes.
The researchers searched the publicly accessible Retraction Watch Database for retracted papers published between 1975 and 2025, using tumor names from the 2021 World Health Organization Classification of Tumors of the Central Nervous System to identify relevant articles. Using records available as of December 31, 2025, the researchers identified 582 retracted papers on CNS tumors published in 217 journals. Of the 217 journals, 16 had each published at least 10 retracted papers, accounting for 42.61% of all retractions. Another 30 journals lacked a 2024 impact factor, and 19 of these had been removed from major journal indexes.
The number of retractions increased over time, peaking at 130 in 2023. Of these articles, 78.01% (454 out of 582) had originally been published after 2015. Nearly three-quarters of the retracted papers (434 out of 582) focused on gliomas, glioneuronal tumors, and neuronal tumors.
Of the 582 papers, 469 (80.58%) were retracted due to research misconduct, with paper mill involvement, image duplication, and compromised peer review among the most common reasons. The highest number of retracted papers came from China, with 401 out of 581 articles (69.02%) based on the first author's country. The United States followed with 68 papers (11.70%), while India accounted for 47 papers (8.09%). However, these figures reflect retraction counts, not retraction rates, as total publications per country were not assessed.
Most retracted papers involved basic research, such as laboratory studies (75.26%, or 438 papers), while clinical research accounted for 17.01% (99 papers). One of the most concerning findings was that many retracted papers continued to be cited after being withdrawn. Of the 582 articles, 515 had received at least one citation, with a combined total of 12,151 citations. Among these 515 papers, 462 (89.71%) continued to receive citations after retraction, and 182 papers (35.34%) received more citations after retraction than they had before it.
These findings suggest that even though a paper has been retracted, its findings may still be used in later research, highlighting the importance of checking a paper's retraction status before citing it.
"The persistence and high rate of post-retraction citations in the CNS tumor field raise concerns about evidence-based patient care. Clinicians and principal investigators are strongly advised to check the retraction status of articles before citing them via databases such as Retraction Watch, PubMed, or Web of Science," the study notes.
The study calls for better systems to alert researchers in neuro-oncology when papers have been retracted, preventing unreliable findings from continuing to influence future research.
