| Affiliation: | 1. Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA American College of Surgeons Cancer Programs, Chicago, Illinois, USA;2. American College of Surgeons Cancer Programs, Chicago, Illinois, USA;3. Department of Pathology, University of California San Francisco, San Francisco, California, USA;4. Department of Pathology, Basingstoke and North Hampshire Hospital, Basingstoke, UK;5. Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA;6. Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA;7. West Virginia University Cancer Institute, Morgantown, West Virginia, USA;8. Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA;9. Department of Surgery, University of Utah Huntsman Cancer Institute, Salt Lake City, Utah, USA;10. Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA |
| Abstract: | The standard for cancer staging in the United States for all cancer sites, including primary carcinomas of the appendix, is the American Joint Committee on Cancer (AJCC) staging system. AJCC staging criteria undergo periodic revisions, led by a panel of site-specific experts, to maintain contemporary staging definitions through the evaluation of new evidence. Since its last revision, the AJCC has restructured its processes to include prospectively collected data because large data sets have become increasingly robust and available over time. Thus survival analyses using AJCC eighth edition staging criteria were used to inform stage group revisions in the version 9 AJCC staging system, including appendiceal cancer. Although the current AJCC staging definitions were maintained for appendiceal cancer, incorporating survival analysis into the version 9 staging system provided unique insight into the clinical challenges in staging rare malignancies. This article highlights the critical clinical components of the now published version 9 AJCC staging system for appendix cancer, which (1) justified the separation of three different histologies (non-mucinous, mucinous, signet-ring cell) in terms of prognostic variance, (2) demonstrated the clinical implications and challenges in staging heterogeneous and rare tumors, and (3) emphasized the influence of data limitations on survival analysis for low-grade appendiceal mucinous neoplasms. |
