JCO Formatting Requirements: Complete Author Guide

JCO requires an abstract for most article types, and Original Reports use a structured abstract. Systematic reviews, consensus guidelines and meta-analyses also use a structured abstract, while other review articles use an unstructured one.

Structured abstract headings (Original Reports):

• Purpose

• Patients and Methods (or Materials and Methods, Methods, or a similar heading)

• Results

• Conclusion

Abstract specifications:

• Word limit: 275 words for Original Reports and Review Articles; 200 words (unstructured) for Clinical Trial Updates

• Structure: Mandatory subheadings as listed above

• Trial registration: ASCO requires the registration identification number and the URL of the trial's registry when you submit

Critical detail: JCO uses "Purpose" not "Objective," "Background," or "Introduction." ASCO does not scrutinize headings at first submission, but expects them at revision. Similarly, "Conclusion" is singular, not "Conclusions."

The abstract for a clinical trial paper should follow a specific formula: Purpose states the hypothesis and primary endpoint. Patients and Methods describes the design, population, intervention, and statistical approach. Results presents the primary endpoint result with confidence intervals. Conclusion states the clinical implication.

Include specific numbers in the abstract. "Overall survival was significantly improved" isn't acceptable at JCO. "Median overall survival was 18.2 months vs 14.1 months (HR, 0.73; 95% CI, 0.60 to 0.89; P =.002)" is what's expected.

JCO allows up to 6 display items (figures and tables combined) for Original Reports. Additional figures and tables may be placed in an appendix to be published online.

Figure specifications:

Table requirements:

• Cite tables in the order they appear in the text, using Arabic numerals

• Place tables at the end of the manuscript

• Table legends include pertinent notes and definitions of all abbreviations and acronyms used in the table

• No table pieces such as Table 1a and 1b; manuscripts with them are returned for correction

• Report actual P values rather than "P >.05"; two digits are sufficient for P > .01

• Report outcomes with both absolute and relative differences and confidence intervals where appropriate

Survival curves: Kaplan-Meier curves are the most common figure type at JCO. The journal expects:

• Risk tables showing the number of patients at risk at selected time points (this can sit below the x-axis)

• For clinical trial outcomes submitted to JCO, the number of patients censored for each arm or group at the same intervals, with reasons for censoring where possible

• Outcomes reported with absolute and relative differences and confidence intervals where appropriate

Waterfall plots and swimmer plots: Ensure bars are clearly labeled and that response criteria (RECIST, etc.) are defined in the legend.

JCO uses its own reference style, numbered in the order of citation, which differs from AMA and JAMA format. ASCO notes that a Journal of Clinical Oncology reference style is available for EndNote and can be applied to all ASCO journals.

In-text citations: Number references in the order in which they are cited in the text.

Reference list format (ASCO's sample style):

Knox S, Hoppe RT, Maloney D, et al: Treatment of cutaneous T-cell lymphoma with chimeric anti-CD4 monoclonal antibody. Blood 87:893-899, 1996

Key formatting details:

• Author names: last name and initials, with the author list followed by a colon (for example, "Dolan ME, Pegg AE:")

• List up to three authors; for more than three, list the first three followed by "et al"

• Journal names abbreviated (for example, "Clin Cancer Res"), followed by volume, page range and year, with no issue number in the sample style

• At first submission, include all customary reference information; ASCO adjusts reference formatting and verifies data against PubMed-indexed citations after acceptance

JCO self-citation: Use "J Clin Oncol" as the abbreviated journal name.

ASCO lists no reference limit for Original Reports. Review Articles are limited to 150 references and Correspondence to 10.

Common reference mistakes: Letting a reference manager's APA or AMA preset reformat the list. Switching citation styles mid-draft without re-running the formatting is the single most common reference error we see in pre-submission review.

JCO uses the term "Data Supplement" for supplementary material. ASCO publishes it online only.

Data Supplement contents:

• Extended methods and statistical details

• Appendix figures

• Appendix tables

• Trial protocols (full or redacted)

• CONSORT flow diagrams (if not in the main manuscript)

• Patient-level data (when appropriate)

Protocol requirement: For interventional studies involving human subjects, ASCO asks for the full protocol, or a redacted version, uploaded as a supplemental file. The full protocol is preferable, but at minimum the submission must include these sections, reflecting the most recent revised version of the protocol:

• Selection of patients, including eligibility and ineligibility criteria

• Schema and treatment plan, including administration schedule

• Rules for dose modification

• Measurement of treatment effect, including response criteria, definitions of response and survival, and methods of measurement

• Reasons for early cessation of trial therapy

• Objectives and the entire statistical section, including end points

ASCO makes the protocol available to editors and reviewers during peer review and publishes it online if the manuscript is accepted. Primary planned endpoints, planned or unplanned subset analyses, and the statistical analysis used to assess them must be clearly stated. Most authors learn about the protocol requirement only after submission, causing delays.

CONSORT compliance: ASCO asks authors of randomized trials and other comparative studies to follow ICMJE and CONSORT guidelines and to submit a CONSORT diagram for studies in which two or more groups are compared. The CONSORT diagram does not count toward the table and figure limit.

Title page (first page of manuscript):

• A succinct title, not longer than 175 characters including spaces, that includes the disease name, drug name and/or clinical trial name where applicable and does not allude to a result or conclusion of the study

• Author list (first name, middle initial, last name, degree(s)) and each author's affiliated institution

• Acknowledgments of research support for the study (all funding sources must also be entered into the submission system)

• Name, affiliation and email address of the corresponding author (only one corresponding author is allowed)

• Running head of 65 characters or fewer, including spaces, as a condensed version of the title

• Where and when the study has been presented in part elsewhere, if applicable

• Disclaimers, if any

Cover letter requirements:

• Confirm the manuscript is original and not under consideration elsewhere

• List any related manuscripts by the same authors

• Describe the clinical significance of the work

• State whether the work was previously presented at a meeting (and which one)

• Mention any suggested reviewers; ASCO encourages authors to suggest up to four reviewers, entered in the submission system

JCO's cover letter is particularly important for clinical trial papers. The editor needs to assess whether the trial is large enough, well-designed enough, and clinically relevant enough for JCO's audience. Include the sample size, primary endpoint, and a brief statement of the main finding.

Clinical trial registration is mandatory. ASCO requires registration of clinical trials in a public trials registry at or before the time of first patient enrollment as a condition of consideration for publication. It accepts ClinicalTrials.gov or any primary register of the WHO International Clinical Trials Registry Platform that includes the minimum 24-item registration dataset. Provide the registration identification number and the URL of the registry when you submit.

Protocol for interventional studies. Described above but worth repeating: ASCO asks for the full protocol, or a redacted version, and it is the item we see authors miss most often in pre-submission review.

ASCO conflict-of-interest disclosure. All authors submit disclosures through ASCO's disclosure database (coi.asco.org). ASCO uses a general disclosure model that covers all financial relationships with companies over the past 2 years, whether or not they relate to the manuscript.

Prior presentation disclosure. If any of the data was presented at a conference (ASCO Annual Meeting, ESMO, ASH, etc.), disclose this in the cover letter and on the title page. ASCO says prior conference presentations do not affect a submission when this information is included.

Author contributions. Co-authors complete an Author Contribution Questionnaire, alongside their conflict-of-interest disclosures, after the submission.

Human investigations statement. Reports on human experimentation must include a statement that the investigators performed the work after approval by a local Human Investigations Committee and in accord with an assurance filed with and approved by the Department of Health and Human Services where appropriate, and a statement that the investigators obtained informed consent from each participant or each participant's guardian.

Statistical methods. ASCO's statistical guidelines ask for two-sided P values in randomized trials (plus the two-sided P value of a standard test if the design was Bayesian or one-sided), actual P values rather than "P >.05", outcomes with absolute and relative differences and confidence intervals where appropriate, and attention to multiple comparisons and the exploratory nature of studies with multiple or secondary end points.

Biomarker and genomic data. ASCO requires datasets relevant to predictive or prognostic markers to be anonymized and submitted with the work as a supplemental file. Before publication, datasets or sequences relevant to the research must be provided in full, either as a supplementary file or deposited in a public database such as GenBank, Gene Expression Omnibus, or Array Express, with the accession number in the text of the final manuscript.

Trade names. Do not use proprietary or trade names in the title or abstract.

In our pre-submission review work with JCO-targeted manuscripts, four gaps show up most often before these papers reach peer review. All four trace back to a written JCO requirement, which makes them cheap to fix before upload.

Statistical reporting thin for trial manuscripts. ASCO's statistical guidelines ask trial authors to report two-sided P values, absolute and relative differences with confidence intervals, and to address multiple comparisons. Submissions where the statistical methods section lacks detail on primary endpoint analysis, power calculation, and handling of missing data tend to draw questions before peer review begins in our pre-submission experience. Reviewers specifically check whether the stated primary endpoint matches the registered protocol.

Non-compliant CONSORT reporting for randomized controlled trials. ASCO asks authors of randomized trials to follow ICMJE and CONSORT guidelines and to submit a CONSORT diagram for studies in which two or more groups are compared. Manuscripts that describe a randomized design in the methods but arrive without the diagram are a common gap in our pre-submission reviews. The flow diagram must account for all participants through each stage from enrollment to analysis.

Protocol not attached for registered trials. For interventional studies, ASCO requires the full protocol or a redacted version. Manuscripts reporting trial results that reference a registry identifier without attaching the protocol document are a recurring gap in our pre-submission reviews. This applies to both primary and secondary endpoint analyses.

Structured abstract not following JCO format for Original Reports. JCO Original Reports require a structured abstract with the following headings: Purpose, Patients and Methods, Results, and Conclusion. Manuscripts submitted with unstructured abstracts or with non-standard heading labels (Background, Methods, Discussion) are expected to be corrected at revision, since ASCO does not scrutinize formatting at first submission. The Conclusion statement must reflect the primary endpoint finding, not a general synthesis.

A Journal of Clinical Oncology formatting and readiness check evaluates manuscript structure, statistical documentation, and trial reporting compliance against these desk-rejection patterns before you submit.

For a manuscript-specific signal before you submit, run a Journal Of Clinical Oncology submission readiness check.

Or see example reports before you finalize.

Authors should submit to Journal of Clinical Oncology when the manuscript is built around clinically meaningful oncology evidence, clear patient or practice implications, and figures that make the treatment, biomarker, or outcomes claim easy to audit. Authors should avoid JCO when the work is mainly exploratory biology, a small institutional series without external relevance, or a methods-heavy analysis that would fit a specialty oncology or translational venue better.

The formatting pass should therefore check more than margins: the abstract, tables, trial identifiers, statistical methods, references, and cover letter all need to show why oncology readers need this paper now.