Lancet Oncology's AI Policy: Declaration Rules and Limits by Content Type

Allowed, with disclosure and oversight:

• Using AI tools to support your work while you remain accountable for every claim

• Documenting the tool name, version, purpose, and your oversight in the AI declaration statement

• Describing any AI used in the research process in the Methods section

Not allowed, or needing particular care:

• Listing an AI tool as an author or co-author

• Using generative AI to create figures or artwork beyond demonstrations of its capabilities in specific contexts

• Putting unpublished manuscripts or confidential data into an AI tool whose terms do not protect their privacy and confidentiality

• Granting an AI tool any right to your materials beyond providing the service to you, including the right to train the AI tool on them

The information for authors does not limit permitted AI use to grammar and language for Articles. That narrower limit applies to Comments and Correspondence.

Comments, Correspondence, and Perspectives. The information for authors describes this blue section content as a space for human interpretation of science and medicine. Use of AI-assisted tools and generative AI is not allowed for Perspectives. For Comments and Correspondence, it is permitted only to assist with grammar and spelling, and AI-assisted tools must not be used to translate Comments or Correspondence at the submission stage, improve arguments, generate new content or sentences, reorder content, shorten or summarise content, alter meaning, or generate, complete, or verify references or citations. If AI has been used, a declaration fully describing how must be included at the submission stage, and any breach of this policy will lead to rejection of the Comment or Correspondence.

Lancet Oncology's information for authors opens its AI section with the Elsevier wording: authors preparing a manuscript for an Elsevier journal can use AI tools to support them, with human oversight and control. The Lancet Group then adds requirements by content type, including the separate AI declaration statement and the limits for Comments, Correspondence, and Perspectives described above.

Check each target journal's current instructions before reusing a disclosure statement.

The information for authors does not give oncology-specific AI rules. These points apply the general rules to common oncology manuscripts.

Phase III clinical trial reports. Authors remain accountable for every clinical claim. AI involvement in interpreting hazard ratios, characterizing adverse event profiles, drawing efficacy conclusions, or formulating treatment recommendations needs careful human verification, and it should be declared in the AI declaration statement and, when it is part of the research process, described in the Methods section. Use AI to support your writing, and make the clinical judgment yourself.

Biomarker and companion diagnostic studies. If your paper uses machine learning to develop a biomarker classifier, that is research AI, described in the Methods section. If you also used an AI tool to edit your Discussion, that is manuscript-preparation AI, disclosed in the AI declaration statement. Keep the two descriptions separate.

Cancer epidemiology studies. If AI coding tools helped you write the scripts to query cancer registries or claims databases, document that use, and make sure the epidemiologists on the team verify the scripts and the clinical interpretation of incidence trends, survival patterns, and risk factor associations.

Systematic reviews and meta-analyses. Where AI is used in the research process, such as screening abstracts or extracting data, the information for authors says that use should be declared and described in detail in the Methods section.

Remember: at Lancet Oncology, manuscript-preparation AI is disclosed in a separate AI declaration statement at the end of the manuscript, and AI used in the research process is described in the Methods section.

Phase III trial: "The authors used ChatGPT (GPT-4, OpenAI) to improve the readability and English language of the Introduction section. No AI tools were involved in trial design, data management, statistical analysis, efficacy assessment, safety evaluation, or interpretation of clinical outcomes. All clinical conclusions were drawn by the study investigators. The authors take full responsibility for the published content."

Biomarker study: "Claude (Claude 3.5, Anthropic) was used to improve the readability of the Discussion section. No AI tools were used in biomarker assay development, statistical analysis, cutoff determination, or clinical interpretation. The authors take full responsibility for the published content."

Epidemiology study: "During the preparation of this manuscript, the authors used ChatGPT (GPT-4o, OpenAI) to improve the clarity of the Results and Discussion sections. GitHub Copilot (Microsoft) assisted with writing SAS scripts for database queries. All scripts were validated by the study biostatistician (E.F.). No AI tools were involved in the interpretation of epidemiologic findings. The authors take full responsibility for the published content."

Systematic review/meta-analysis: "The authors used Claude (Claude 3.5, Anthropic) to improve the language and readability of selected sections of the manuscript. The systematic search, study selection, data extraction, risk of bias assessment, meta-analysis, and evidence grading were performed entirely by the author team without AI assistance. The authors take full responsibility for the published content."

Notice that these statements name the tool and version, the purpose, and the extent of oversight, as the information for authors asks. Place the statement in a separate AI declaration statement at the end of the manuscript.

AI policies differ across journals and are updated often, so check each target journal's current instructions. For Lancet Oncology, the policy described above is the one in its August 2026 information for authors: AI use is allowed to support authors with human oversight and a disclosure statement, and Comments, Correspondence, and Perspectives are restricted.

The information for authors says editors reserve the right to determine whether the use of AI is appropriate, and that any breach of the AI policy for a Comment or Correspondence will lead to rejection. The Lancet Group's research integrity page says that if ethical or integrity concerns are flagged, editors may notify authors' institutions for investigation, even if the journal is no longer considering the paper.

During peer review: The research integrity page says editors assess all submissions for potential integrity issues and that peer review also plays a role in evaluating ethical standards and methodological rigor.

After publication, the escalation: The Lancet Group lists the corrective actions it can take: a Department of Error, an expression of concern, retraction and republication, or retraction. The clinical weight of Lancet Oncology publications amplifies every consequence.

Keep human oversight visible. The information for authors says AI tools must never be used as a substitute for human critical thinking, expertise, and evaluation. Write and verify the substance yourself, check every AI-generated reference, and document what the tool did.

Prepare the disclosure early. Collect the tool name, version, purpose, and extent of oversight for every AI use while you work, so the AI declaration statement is accurate. If you have backup journals, adapt the statement to each journal's current instructions.

Mention AI in the cover letter. While the formal disclosure goes in the AI declaration statement, mentioning AI use in the cover letter is good practice for Lancet Oncology submissions. Proactive transparency signals that you take the policy seriously.

Watch for co-author AI use. The corresponding author needs to collect every co-author's AI use for the declaration statement and check that it meets the oversight and accountability rules.