Lancet Oncology Formatting Requirements: Complete Author Guide

Lancet Oncology publishes a focused set of article types, each with specific length requirements. The editorial office is strict about word limits, and even small overages can result in administrative returns.

Word counts exclude the abstract, references, figure legends, tables, and the Research in Context panel. The 3,000-word limit for Articles is notably tighter than comparable oncology journals like JAMA Oncology, which also allows 3,000 words but has different inclusion/exclusion rules for word counts.

The 30-reference limit for Articles is also strict. If you're writing a clinical trial report, you'll need to be selective about which prior studies you cite. Move extensive literature discussion to the appendix if needed.

Lancet Oncology requires a structured abstract for Articles, limited to 300 words. The required headings are:

• Background
• Methods
• Findings (not "Results")
• Interpretation (not "Conclusions")
• Funding

Two things to note here. First, Lancet Oncology uses "Findings" instead of "Results" and "Interpretation" instead of "Conclusions." Using the wrong headings will get your paper returned. Second, the Funding section is part of the abstract itself, not a separate element. Name all funding sources in a single sentence at the end of the abstract.

The Background section should be 1-2 sentences establishing the rationale. Don't open with "Cancer is a leading cause of death worldwide" or similar generic statements. Get straight to the specific question.

The Methods section should cover study design, setting, participants, interventions, and primary endpoint in concise terms. For clinical trials, include the trial registration number here.

Findings must include specific numerical results: hazard ratios, confidence intervals, P values, and response rates for primary and key secondary endpoints. Lancet Oncology reviewers expect to evaluate the data from the abstract alone.

Interpretation should be 2-3 sentences that put your findings in clinical context. What do these results mean for patients? Don't overstate or suggest practice changes that your data don't directly support.

This is the most distinctive formatting element of Lancet journals, and it's mandatory for all Articles. The Research in Context panel is a structured box with three sections:

Evidence before this study: Describe the systematic search you conducted to identify existing evidence. Include databases searched, search terms, date range, and language restrictions. Summarize what was known before your study.

Added value of this study: Explain what your study contributes beyond existing evidence. Be specific about the novelty.

Implications of all the available evidence: Discuss what the totality of evidence (including your study) means for clinical practice, policy, or future research.

The Research in Context panel doesn't count toward the 3,000-word limit, but it must be substantive. Lancet editors take this seriously. A vague or poorly researched Evidence before this study section will draw criticism. You need to show that you actually conducted a systematic search, not just cited papers you already knew about.

The title page must include:

• Full title (avoid abbreviations)
• All author names with affiliations
• Corresponding author's contact details (address, phone, email)
• Word count for body text
• Number of figures, tables, and references
• Contributor statement (who did what)

Lancet Oncology uses its own contributor statement format rather than CRediT roles. Each author's specific contributions must be described, and all authors must confirm they had access to the raw data. At least one author (usually the corresponding author) must serve as guarantor, taking responsibility for the integrity of the work.

Lancet Oncology permits approximately 5 display items (figures and tables combined) for Articles. Multipanel figures count as one item.

Figure requirements:

• Minimum resolution: 300 DPI for photographs, 600 DPI for line art
• Accepted formats: TIFF, EPS, or high-resolution JPEG
• Maximum file size: 10 MB per figure
• Single column width: 79 mm (3.1 inches)
• Double column width: 168 mm (6.6 inches)
• Font in figures: must be legible at final print size (minimum 6-point)
• Color figures are free online and in print
• Each figure uploaded separately

Table requirements:

• Created in Word using table function
• Every column must have a header
• No vertical rules
• Horizontal rules at top, bottom, and below headers only
• Use footnotes for abbreviations (superscript letters)
• P values to 2-4 decimal places

For clinical trial reports, Kaplan-Meier curves must include numbers at risk below the x-axis. Forest plots should show individual and pooled effect estimates with confidence intervals. These are standard expectations but frequently done incorrectly.

Lancet Oncology uses the Lancet reference style, a numbered format based on Vancouver conventions with some specific differences.

Key formatting rules:

• Superscript citation numbers in text, placed after punctuation
• List all authors up to 6; for 7 or more, list the first 3 followed by "et al"
• Journal titles abbreviated per NLM/Medline conventions
• Use italics for journal titles
• Include volume and page range, but not issue number
• No period after journal abbreviation

Example reference:

1 Smith AB, Jones CD, Williams EF, et al. Immunotherapy combinations in advanced melanoma: a phase 3 randomized trial. Lancet Oncol 2025; 26: 312-20.

Note the formatting specifics: italicized journal title, bold volume number, shortened final page number (312-20, not 312-320), and a space before the semicolon after the year. These details differ from standard Vancouver style and will be flagged if incorrect.

The reference manager style for Lancet journals is available in Zotero, EndNote, and Mendeley. Make sure you're using the Lancet-specific style, not generic Vancouver.

Lancet Oncology calls supplementary material the "appendix." It's published online and undergoes full peer review.

The appendix can include:

• Additional figures and tables
• Extended methods (including full statistical analysis plans)
• Trial protocols (required for clinical trial reports)
• CONSORT/PRISMA flow diagrams (if not in main text)
• Additional subgroup analyses
• Sensitivity analyses

For clinical trials, Lancet Oncology requires the full trial protocol to be submitted as part of the appendix. This is not optional. The protocol is made available to reviewers and, if the paper is accepted, published alongside the article.

Appendix items are labeled as "appendix p 1," "appendix p 2," etc., referring to page numbers within the appendix document. This is different from most journals, which label items as "Supplementary Figure 1," etc.

Lancet Oncology strongly prefers Word submissions. The journal's editorial workflow is built around Word documents, and LaTeX submissions create friction during production.

Word submissions:

• 12-point font (Times New Roman or similar serif font)
• Double-spaced throughout
• Continuous line numbering
• Wide margins (at least 1 inch / 2.5 cm)
• Page numbers on every page

LaTeX submissions:

• Not the standard workflow; convert to Word if at all possible
• If you must submit LaTeX, provide compiled PDF and all source files
• Expect conversion issues during production, especially with complex tables

For oncology manuscripts, Word is almost always the right choice. Clinical trial reports, observational studies, and translational research papers don't typically require the mathematical typesetting that makes LaTeX valuable. Save yourself the hassle and submit in Word.

Lancet Oncology has formatting and policy elements that set it apart from other oncology journals. These are the ones that most commonly trip up first-time submitters.

1. Research in Context is non-negotiable. The panel must demonstrate a genuine systematic search, not just a narrative summary of papers you know. Reviewers and editors evaluate the quality of your search strategy.

2. "Findings" and "Interpretation," not "Results" and "Conclusions." This is the most common abstract heading error. It seems trivial but will get your manuscript returned.

3. Protocol submission for trials. The full trial protocol must be submitted with clinical trial reports. This isn't just a summary; it's the actual protocol document, including statistical analysis plan. If your protocol is proprietary, discuss access arrangements with the editorial office before submission.

4. Independent statistical review. For clinical trial reports, Lancet Oncology may request independent statistical verification of your results. Be prepared to share raw data and analysis code with a statistician appointed by the journal.

5. Presubmission enquiry recommended. Lancet Oncology encourages presubmission enquiries for Articles. Submit a brief summary of your study and the editors will tell you whether it's likely to be of interest. This saves time compared to formatting a full submission that gets desk-rejected.

The most frequent reasons for administrative return at Lancet Oncology:

• Missing Research in Context panel
• Using "Results/Conclusions" instead of "Findings/Interpretation" in the abstract
• Exceeding the 3,000-word limit or 30-reference limit
• Missing trial protocol in the appendix for clinical trial reports
• CONSORT/PRISMA checklists not uploaded
• Funding not listed within the abstract
• Contributor statement missing or incomplete