When submitting an abstract or late-breaking placeholder to any ASCO Meeting, the First Author must agree to the following Prior Presentation/Publication Policy and Confidentiality Policy on behalf of all parties involved with the study. The First Author is responsible for communicating the policies to all involved parties, including co-authors and sponsors, complying with these policies, and will be held accountable for any policy violations of the abstract.

Please note: Trials in Progress (TPS) abstracts are excluded from these policies.

Prior Presentation/Publication Abstract Submission Policy


Prior to the ASCO Meeting, the contents and conclusions of the abstract must not be presented at or published in conjunction with any scientific, medical, or educational meeting with the following exceptions: 

  • Studies previously submitted to ASCO Meetingsi are eligible for acceptance even if previously presented or published in the scientific, medical, or educational arena. Abstracts presented at these ASCO Meetingsi may also be submitted for presentation at any other ASCO Meeting. Authors are strongly encouraged to provide updated data in the abstract, as the novelty of the data will be taken into account during the abstract selection process. (No new or updated data may be added to an abstract after it has been formally submitted.) 
  • Study results may be presented at closed (non-public) meetings, such as investigator or cooperative group meetings, so long as no meeting materials are publicly disseminated.


In addition, the contents and conclusions of the abstract must not be published in a scientific, medical, or educational publication (in any medium), in whole or in part, before the abstract is publicly released by ASCO. Pre-prints (non-peer-reviewed online comment drafts) are permitted before the abstract is submitted.

Any violation of these policies may subject the abstract to rejection or removal from the ASCO Meeting.

Confidentiality Policy 

Compliance with the Confidentiality Policy by all parties related to the abstract is the responsibility of the First Author, and the First Author will be held accountable for any violations of ASCO’s Policy. 

Once an abstract is submitted to an ASCO Meeting, the abstract and any study data to be presented at the ASCO Meeting are confidential. For late-breaking placeholders, the Confidentiality Policy does not apply until the study data is submitted to ASCO. For abstracts previously presented in an ASCO Meeting,i the Confidentiality Policy applies only to new or updated data or information in the study.   

After the abstract is submitted to and prior to the abstract information being publicly released in conjunction with an ASCO Meeting, the author, coauthors, sponsor of the research, journalists, and others must not: 

  • make the information public, or provide it to others who may make it public (such as news media), or
  • use the information for trading in the securities of any issuer, or provide it to others who may use it for securities trading purposes.

Confidentiality lifts once ASCO publicly releases the abstracts in conjunction with the ASCO Meeting.ii Once the abstract is publicly released by ASCO, the Confidentiality Policy is no longer in effect, and authors are free to discuss their study findings publicly, although ASCO expects the formal presentation (including slides and/or poster) of the study data to be made at the ASCO Meeting.  

If, after submission, an abstract or its data has been released in a manner that does not comply with ASCO’s Confidentiality Policy, the abstract is not eligible for inclusion in the ASCO meeting. The abstract may be subject to rejection or removal unless an official Confidentiality Policy Exception applies (see additional information on Confidentiality Policy Exceptions below).

Even when an Exception applies or is granted, ASCO retains the right, in its discretion, to accept or not accept any abstract for the ASCO Meeting on the basis of peer review and, once an abstract is accepted, to place the abstract or change its placement in the ASCO Meeting program depending on the extent of information released. If an Exception applies or is granted, the study is unlikely to be included in the official press program for the ASCO Meeting.

Email specific inquiries about exceptions to ASCO’s Confidentiality Policy.

Confidentiality Policy Exceptions

ASCO recognizes that certain federal and international laws require disclosure of certain clinical trial results 1) through federal and international registries within a certain time period of trial completion, or 2) in relation to drug approvals by federal and international regulatory agencies. Should disclosure of confidential information be required in either of these circumstances before ASCO makes the abstract public, the required disclosure will not be viewed as a breach of ASCO’s Confidentiality Policy.

Other than required disclosure for regulatory purposes as outlined above, Exceptions to ASCO’s Confidentiality Policy require advance communication with ASCO prior to any public release. Communication should be directed to the CP Exceptions team with at least 48 hours’ notice where feasible.

Exceptions to the Confidentiality Policy may be granted by ASCO in extremely rare circumstances for public health reasons or to meet the requirements of state, national, or international government agencies. In these rare cases, requests should be directed to the CP Exceptions team for step-by-step guidance. 

A Securities and Exchange Commission (SEC) Exception may apply to the extent required to comply with securities laws.

SEC Exceptions

In general, an abstract in this situation is still eligible for inclusion in the ASCO Meeting provided that the company submits to ASCO, in advance of any public release, a letter signed by the company’s legal counsel that contains the abstract title, indicates the format/nature of the public disclosure, and attests that (a) public disclosure of the information is necessary for the company to comply with applicable securities laws, and (b) the information disclosed is the minimum necessary for such compliance. In addition, ASCO requires that the lead author be copied on the company’s request for an exception.

If the submission is in order, the SEC Exception is self-executing and does not require pre-approval from ASCO. If an SEC Exception applies, the abstract is eligible to be peer-reviewed and will not be rejected or removed from the meeting on the basis of a Confidentiality Policy violation.

To the extent that the SEC Exception applies, corporate partners of the company may, jointly or separately, issue a press release with the same information at that time. The abstract itself may not be released publicly by the company or lead author, as ASCO holds the copyright to the abstract. 

Subject always to the company’s regulatory obligations, ASCO would strongly prefer that the company’s press release: 

  1. summarize study data cited in the abstract in a qualitative fashion rather than providing specific quantitative information;
  2. avoid interpretations about the implications of the data for practice; and
  3. note that full data has been submitted to the ASCO Meeting.

By way of illustrating these preferences, a statement that a study “met its primary endpoint of increasing survival” is considered qualitative, while a statement that “survival was increased by 20% with the study drug” is considered quantitative. A quote such as “We are encouraged by these promising results” would not be viewed as interpretive, while a quote such as “These findings support this drug as first-line therapy in lung cancer” could be seen as an interpretation of the data. Information that is also appropriate for a press release includes that which is already publicly available.

For companies’ convenience, a sample press release is available further illustrating these preferences.

If the press release or press coverage conveys significantly more information than ASCO’s stated preferences and illustrated by the sample press release, the abstract may or may not be accepted into the ASCO Meeting on the basis of peer review. If the abstract has already been accepted when the press release is issued, the abstract’s placement in the meeting program may be changed.

The Exception will be publicly noted on ASCO.org once the abstract has been formally accepted to the meeting.

Other Situations

ASCO does not grant Exceptions for preprint publications (non-peer-reviewed online comment drafts) occurring after abstract submission. Once an abstract has been submitted to the ASCO Meeting, preprint publications will be considered violations of ASCO’s Confidentiality Policy.

Specific inquiries about exceptions to ASCO’s Confidentiality Policy should be emailed to the CP Exceptions team.

iASCO Meetings:

  • ASCO Gastrointestinal Cancers Symposium
  • ASCO Genitourinary Cancers Symposium
  • ASCO Quality Care Symposium
  • ASCO Breakthrough
  • ASCO Plenary Series

ii Most abstracts will be publicly available online at ASCO.org approximately one week before the Annual Meeting, with Late-Breaking Abstracts (LBAs), including Plenary, becoming publicly available in conjunction with the Annual Meeting. Abstracts in the symposia listed above will be publicly available online at ASCO.org on or just before the opening day of the symposium. Exact posting dates and times will vary from year to year. Press releases issued at or after ASCO’s public release do not violate ASCO policies.