Q: Staging of cancer is traditionally important. What is the AJCC, who funds it, what does it do? How essential is it for the proper care of cancer patients?
A: The American Joint Committee on Cancer (AJCC) is a multidisciplinary organization with roots dating back to 1959 with the goal of developing and promoting national standards for cancer staging in the U.S. Currently, 22 member organizations spanning multiple disciplines – cancer care, registry, cancer control, pathology, epidemiology, education, outreach and advocacy – support its mission. The AJCC provides worldwide leadership in the development, promotion and maintenance of evidence-based systems for the classification and management of cancer in collaboration with multidisciplinary organizations dedicated to cancer surveillance and to improving care. Administrated by the American College of Surgeons (ACoS) with governance overseen by representatives from founding and other sponsoring organizations, financial support is also provided by several of its member organizations. Notably, other than its core administrative team, it is a nearly completely volunteer-led organization that receives evidence-based input from hundreds of expert volunteers.
Cancer staging serves as the principal communication tool between physicians and their patients and among physicians for clinical decision making and prognostic assessment. Cancer staging is also used for clinical trial design, eligibility, stratification, and analysis. It serves a critical role as the foundation for reporting on an institutional, regional, state, national, and international registry level to facilitate understanding of the broader cancer landscape. With all of this, cancer staging is a key pillar in translational research.
The AJCC published the First Edition AJCC Cancer Staging Manual in 1977. To maintain relevance, AJCC cancer staging systems have been revised and expanded every 5 to 7 years across myriad disease sites included in the manual. The most recent version – the Eighth Edition AJCC Cancer Staging Manual – was published in late 2016 and implemented nationwide in the U.S. on January 1, 2018. It is likely that other countries will also adopt these new staging systems.
The foundational elements of AJCC staging are disease-site specific and anatomic-based (TNM system). Components of the TNM staging system include T (primary tumor), N (regional node and non-nodal regional disease), and M (distant metastasis). The TNM-based system has been employed globally, and continues to benefit from a 30-year partnership with the Union for International Cancer Control (UICC). Cancer staging is performed for a patient at presentation as well as at varying times during their cancer continuum. Such staging classifications include: clinical and pathological (the two most commonly used), posttherapy/post-neoadjuvant therapy (for patients who receive “upfront” systemic and/or radiation treatment as an initial component of their care), recurrence/retreatment (for formal cancer restaging), and autopsy (aTNM). Patients are grouped into cohorts according to risk into various prognostic stage groups.
Despite its success over the past several decades, TNM/anatomic-based staging systems have been de facto constrained in their ability to accommodate improved understanding of cancer biology. In order to be useful, however, they need to be clinically relevant, reflect contemporary practice, and be optimally refined by iterations as our understanding of a given cancer matures.
In an effort to retain clinical relevance, the AJCC has expanded its principles of cancer staging to include non-anatomic based factors (e.g., Gleason score, PSA, mitotic rate) beginning with the 6th Edition (2002), and in the 8th Edition has integrated molecular signatures into some staging chapters (e.g., breast). Formal AJCC acceptance criteria have also been recently developed to serve as a framework for inclusion of contemporary risk models. These changes are overall reflective of a strategic evolution from population-based staging to a more personalized approach.
Given the rapid advances in our understanding of the clinical, molecular, and immunological underpinnings of cancer across multiple cancer types, it is likely that a less “staccato” approach to cancer staging will be devised and implemented by the AJCC; strategically configured and coordinated iterative or “rolling” updates can more efficiently exploit integration of clinically relevant advances into the cancer staging arena. Failure to maintain relevance in this exciting and unprecedented era of cancer discovery and care will eventually render any staging system obsolete.
Jeffrey Gershenwald’s contact info is included in the author affiliations at the top of this page.
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