EP737 - Differences in Phenotype in Sporadic Versus Inherited Desmoid Disease

Monday, May 12, 2025

10:36 AM – 10:41 AM PT

ePoster Presenter(s)

Marco Zoccali, MD

Assistant Professor of Surgery
Global Center for Integrated Colorectal Surgery & IBD Interventional Endoscopy Columbia University Irving Medical Center / New York Presbyterian Hospital
Columbia University
New York, New York, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

AS

Aurora Sullivan, MD

Resident Physician
Mount Sinai Hospital
New York, New York, United States

Disclosure information not submitted.
BC

Beatrix H. Choi, MD

Resident Physician
Global Center for Integrated Colorectal Surgery & IBD Interventional Endoscopy Columbia University Irving Medical Center / New York Presbyterian Hospital
Columbia University Medical Center
New York, New York, United States

Disclosure information not submitted.
RK

Ravi P. Kiran, MD

Professor of Surgery
Global Center for Integrated Colorectal Surgery & IBD Interventional Endoscopy Columbia University Irving Medical Center / New York Presbyterian Hospital
New York, New York, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Senior Author(s)

JC

James M. Church, MD

Professor of Surgery
Global Center for Integrated Colorectal Surgery & IBD Interventional Endoscopy Columbia University Irving Medical Center / New York Presbyterian Hospital
Leola, Pennsylvania, United States

Disclosure information not submitted.

All of the relevant financial relationships listed below have been mitigated.

Marco Zoccali, MD: This individual has no financial relationships with ineligible companies.

Ravi P. Kiran, MD: This individual has no financial relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: Desmoid tumors are benign neoplasms of myofibroblasts which can occur either sporadically or in conjunction with Familial Adenomatous Polyposis (FAP), a hereditary colon cancer syndrome. Sporadic tumors are caused by a mutation in oncogene CTNNB1 (coding for  catenin), while FAP-associated tumors are driven by inactivating mutations in APC. Desmoid tumors are prone to recurrence after surgical resection. Medical treatments include a range of chemotherapies, tyrosine kinase inhibitors, and γ-secretase inhibitors. Tumors vary in presentation, clinical course, and response to treatment. We hypothesized that the difference in genotype may account for some of the phenotypic variation, hence we conducted a retrospective study comparing patient characteristics, surgical history, tumor characteristics, response to treatment, and recurrence after surgical resection between sporadic and FAP-associated desmoid tumors.

Methods/Interventions: We used the Columbia University Medical Center pathology database to identify all histologically diagnosed desmoid tumors from 2003 to 2023. Patients under age 18 as well as those with incomplete records were excluded. Data regarding patient characteristics, surgical history, tumor characteristics, response to treatment, and recurrence after resection were obtained. The primary end points are listed in the table. Results were categorized into FAP associated tumors and sporadic tumors, and data were compared between these groups. Categorical variables were compared using the Fisher’s Exact Test due to the small sample size of the FAP cohort, and mean values were compared with two-sample t-tests, with a significance threshold of less than 0.05.

Results/Outcomes: Eighty-four patients were included, 76 (90.5%) with sporadic desmoids and seven patients (8.3%) with FAP associated desmoids. Demographics were comparable between the groups. Surgical resection was the most common treatment for both groups (80% in the sporadic group and 71% in the FAP patients). The results of end point comparison are listed in the table. Two were statistically significant: patients with FAP-associated desmoid tumors were more likely to have multiple tumors (86% vs 20%, p< 0.01) and experience recurrence after resection (60% vs 15%, p< 0.05). This is what would be expected in patients with a constitutional mutation versus as sporadic mutation. Results also suggest a role for abdominal surgery in precipitating FAP desmoids.

Conclusion/Discussion: The differences in the genetic drivers of desmoid tumors between sporadic desmoids (monoallelic sporadic mutations in an oncogene) and FAP (biallelic mutations, one constitutional and one sporadic) impact clinical presentation and prognosis; this can inform the discussion with patients and guide the treatment strategy.