19 (S0140). - A Retrospective Analysis of Tumor Budding, Staging, Invasion, and Immune Response in Patients Diagnosed With Non-Hereditary Young Onset Colorectal Cancer

Hailey Gosnell, BS¹, Mohamad Mouchli, MD², Christopher Mason, PA-C¹, Marrieth G. Rubio, MD², David P. LeBel, II, MD¹, Douglas J. Grider, MD¹; ¹Virginia Tech Carilion School of Medicine, Roanoke, VA; ²Carilion Clinic, Roanoke, VA

Introduction: Tumor budding is an adverse prognostic factor in colorectal cancer, has been studied extensively in patients with somatic, microsatellite stable variants, and is found in 20-40% of such cases. However, the presence and significance of this histopathologic phenomenon in young patients diagnosed with non-hereditary colon cancer is to be determined. In this study, our aim was to ascertain presence of tumor budding in young patients diagnosed with non-hereditary cancer and investigate correlations of this prognostic feature with other prognostic factors such as staging, invasion, and immune response trends.

Methods: In this retrospective observational study, we selected young patients (18- 50 years old) with histopathologic diagnosis of non-hereditary colorectal adenocarcinoma at Carilion Clinic, Roanoke, from 2002 to 2017 and followed through 2011-2019. Patients with inflammatory bowel disease and those with predisposing genetic syndromes were excluded. Patient demographics, polyps’ features, cancer features, colonoscopy reports, and mortality were obtained from electronic medical record. Two pathologists reviewed pathology slides to minimize inter-pathologist variability in histologic diagnosis. The cumulative risk of mortality among patients with different pathologic features were estimated using Kaplan Meier curves.

Results: One hundred and thirty nine patients (mean age, 41.6±6.9 years) with non-hereditary colorectal cancer were identified. One hundred and four of these cases displayed tumor budding on histology (74.8%). Tumor budding was significantly correlated with lymphovascular and perineural invasion (p < .01 for both). Tumor budding grade was also significantly correlated with high cancer stage (p < .01), with intratumoral lymphocyte and neutrophil presence (p < .01) and the presence of tumor deposits (p < .01). Lastly, the occurrence of a Crohn-like response, a histologic indicator for an immune reaction to the colon cancer, was noted to be significantly higher in neoplasms affected by higher grade tumor budding (p< .01).

Discussion: Tumor budding was found in the majority (74.8%) of young non-hereditary colorectal cancer patients, suggesting that this phenomenon is much more prevalent in this subpopulation than in the somatic, microsatellite stable colorectal cancer group.  Tumor budding was also significantly correlated with low and high tumor stages as well as lymphovascular and perineural invasion in young patients with non-hereditary colon cancer.


Table 1: Table summarizing tumor budding correlations with staging, invasion, and immune response trends.

Disclosures:
Hailey Gosnell indicated no relevant financial relationships.
Mohamad Mouchli indicated no relevant financial relationships.
Christopher Mason indicated no relevant financial relationships.
Marrieth Rubio indicated no relevant financial relationships.
David LeBel indicated no relevant financial relationships.
Douglas Grider indicated no relevant financial relationships.