Appendix cancer guidelines shape almost every decision a patient and family will face: when to operate, when to refer to a peritoneal surface malignancy center, when to use systemic chemotherapy, when to watch and wait. The quality of those guidelines depends on how the people writing them actually work together. A new paper in Annals of Surgical Oncology pulls back the curtain on that process.

The Peritoneal Surface Malignancy (PSM) Consortium published a description of how it ran its most recent guideline update cycle. The disease-site leaders were trainees, residents and fellows, not senior faculty. Dr. Kiran Turaga of Yale, an Appendicure Partner, served as senior author. The model has direct relevance for anyone who relies on appendix cancer guidelines to make care decisions.

What the PSM Consortium did to update appendix cancer guidelines

Over seventeen months, a team of 317 people including residents, fellows, faculty, and patient advocates updated five existing PSM guidelines and created one new guideline covering malignant gastrointestinal obstruction. The disease sites covered include appendiceal cancer, gastric cancer with peritoneal spread, colorectal peritoneal metastases, neuroendocrine tumors, and peritoneal mesothelioma.

The team used a modified Delphi method, which is a structured way of moving a group toward agreement through repeated rounds of voting and revision. Trainees ran the small disease-site teams. They led the systematic reviews, synthesized faculty input, and brought recommendations forward. Eleven systematic reviews underpinned the final guideline language.

Why a flat structure mattered

The authors describe the organizational design as a small-world network, which is academic shorthand for a structure where most people are connected through a small number of links. The point is that nobody had to wait in a long queue to reach a decision-maker. Trainees coordinated horizontally with each other and vertically with faculty mentors and patient advocates without going through layers of approval.

Hybrid communication, meaning a mix of regular video meetings, asynchronous written feedback, and peer mentoring, kept the work moving. The result was faster turnaround on disagreements and faster integration of new evidence into the recommendations.

What this means for appendix cancer guidelines going forward

Appendix cancer guidelines are notoriously hard to write. The disease covers five distinct histologies (LAMN, HAMN, appendiceal adenocarcinoma, goblet cell adenocarcinoma, and undifferentiated carcinomas) and clinical behavior varies dramatically within each. The evidence base is thin compared to colorectal cancer, and randomized trials are rare. Most recommendations rest on retrospective series and expert consensus, which makes the consensus process itself a critical part of guideline quality.

Three things stand out for the appendix cancer community.

The PSM Consortium guidelines sit alongside other major efforts, including the NCCN Appendix Cancer Guidelines and the PSOGI consensus documents. Updates from the Consortium feed into the broader evidence landscape that NCCN panels and individual treating centers draw from. When the Consortium moves faster, the rest of the field has more current material to work with.

The trainee-led model brings more hands to the literature review. For a rare disease where the published evidence is scattered across small institutional series and registry analyses, having eleven systematic reviews completed in seventeen months is meaningful. Each one represents pooled effort that no single faculty member could realistically deliver alongside a clinical practice.

Patient advocates were part of the 317-member team. That matters because appendix cancer guidelines only translate to better care if they reflect what patients actually face: access barriers, decision points where preferences matter, and the cost of follow-up testing. Advocate involvement at the drafting stage is not the norm in surgical oncology, and seeing it here is a healthy signal.

Questions to ask your care team Which appendix cancer guidelines does my treating center follow for my specific histology?Are the recommendations my team is using based on the most recent PSM Consortium, NCCN, or PSOGI updates?If my case sits at the edge of the guideline (rare histology, unusual presentation), how was the decision reached?Is my center connected to a peritoneal surface malignancy program with experience in my specific subtype?

What the authors suggest next

The authors recommend testing the model in other settings, including smaller institutions, non-academic environments, and fields outside surgical oncology. They specifically suggest involving early-career professionals and contributors from diverse backgrounds to replicate the structure.

For Appendicure, the takeaway is straightforward. Appendix cancer guidelines are not handed down from on high. They are built by working groups that include trainees, faculty, and patient voices, and the quality of those guidelines depends on how well that group functions. Knowing the structure helps patients ask better questions when their care team references a guideline, and it gives the community a clearer picture of where the next round of updates will come from.

Read Next: Appendix Cancer Finally Gets It’s Own Spotlight

Citation

Godfrey EL, Schultz KS, Bansal VV, Su DG, Butensky SD, Brown LM, Godley FA, Mahoney F, Wilkins S, Izquierdo F, Gunderson CG, Turaga KK. Leading Consortiums from the Ground Up: Leveraging Trainee Collaboration to Create Consensus Guidelines. Annals of Surgical Oncology 2026.

PMID: 42069992  ·  DOI: 10.1245/s10434-026-19740-9

Funded in part by NIH awards 1L30CA294369-01 and T32 CA233414, the Irving Harris Foundation, and Yale University.

Appendicure  ·  Patient education and advocacy for appendiceal cancer