Medical and Health Content on cancer.org

The American Cancer Society is committed to giving you trustworthy, up-to-date information about cancer. Our content is developed with your needs in mind, to make cancer information easier to understand and use. It’s written by medical professionals and carefully reviewed for accuracy. Our goal is to give you answers you can rely on, help you understand what’s happening, and support you through every step of your cancer experience.

Here’s how we make that possible.

Who writes our content?

All of our cancer information is written by health care professionals working as full-time members of our Medical and Health Content Team, with input and review from experts across the organization. These professionals include:

• Oncologists and other medical doctors with experience in oncology and public health
• Advanced practice oncology nurses with hands-on clinical experience and deep knowledge of cancer care
• Researchers
• Public health experts

Our editorial process

We follow an editorial process to ensure every page on cancer.org is accurate and easy to understand. Our content is regularly reviewed and updated based on the most recent data, scientific research, and cancer care and treatment guidelines.

Here’s how we keep our information trustworthy and useful:

• We regularly update all content and monitor changes from trusted sources, including:
  • U.S. Food and Drug Administration (FDA) announcements
  • Annual ACS Cancer Facts & Figures reports
  • SEER (Surveillance, Epidemiology, and End Results) cancer statistics
  • Updates to cancer staging categories and treatment guidelines
• Our full-time medical editors, who are all health care professionals, do thorough literature reviews to revise existing content and guide the development of new topics. These experts carefully research each topic using trusted, evidence-based sources, such as:
  • Peer-reviewed scientific and medical journals
  • National and international clinical guidelines
  • Standard medical and nursing textbooks
  • Reports and recommendations from the American Cancer Society and other leading health organizations
• Our editorial team applies best practices in:
  • Health literacy
  • Plain language
  • Health equity and inclusive communication

This helps make sure the information is not only accurate, but also clear, respectful, and accessible to more people.

• Our content is peer reviewed by subject matter experts, both within the American Cancer Society and through our partnership with the American Society of Clinical Oncology (ASCO), whose patient education advisory committee includes practicing oncologists and other health care professionals and specialists.
• We collaborate with search and user experience experts (SEO and UX) to make sure our content answers real questions people have when searching for cancer information online, and that it’s easy to find and use.
• We welcome feedback from the public. When someone contacts us to share a concern or suggestion, our team reviews the content to see if updates are needed.

Together, these steps ensure our content reflects the latest science, meets the needs of people affected by cancer, and remains one of the most trusted sources of cancer information online.

How we fund our content

The American Cancer Society is a nonprofit organization. Our cancer information is made possible primarily by donations from individuals and families, many of whom have been affected by cancer. We also receive grants to support specific content initiatives like language translation or the addition of video, animations, and image galleries.  

If you have found our content helpful, consider making a donation to support our continued work.

How we stay independent

Our health content is created based on evidence, not financial interests. We do not allow donors, political parties, pharmaceutical companies, or other entities to influence our content. Even in cases where grants have been provided for specific initiatives, grantors have no influence or insight into any phase of content planning, development, or publication. This ensures that:

• Editorial decisions are made independently.
• Content reflects only medical evidence and public health guidance.
• Our role remains a neutral, trusted source of information.

Our content usage policy

American Cancer Society medical information is copyrighted material. See our Content Usage Policy to learn more or submit a request.

How to cite cancer.org

You may cite cancer.org in academic papers, publications, presentations, or reports. Below are examples in several commonly used citation styles. Each includes the page title, organization name, date last updated, full URL, and access date (where required).

• American Medical Association (AMA):
  American Cancer Society. What Is Cancer? Updated May 1, 2024. Accessed July 1, 2025. https://www.cancer.org/cancer/understanding-cancer/what-is-cancer.html
• American Psychological Association (APA):
  American Cancer Society. (2024, May 1). What is cancer? https://www.cancer.org/cancer/understanding-cancer/what-is-cancer.html
• Modern Language Association (MLA):
  “What Is Cancer?” American Cancer Society, 1 May 2024, www.cancer.org/cancer/understanding-cancer/what-is-cancer.html.
• Chicago Manual of Style (CMOS):
  American Cancer Society. “What Is Cancer?” Last modified May 1, 2024. https://www.cancer.org/cancer/understanding-cancer/what-is-cancer.html