Mohamad Mouchli, MD1, Miranda Gerrard, MD1, Adil S. Mir, MD2, Lindsey Bierle, DO1, Shravani R. Reddy, MD2, Christopher Walsh, MD3, 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; 3Virginia Tech Carilion, Roanoke, VA
Introduction: It was reported that young patients diagnosed with non-hereditary colorectal cancer have unfavorable pathologic characteristics. we aimed to assess pathologic features of non-hereditary young onset colorectal tumors and its impact on survival and to assess risk factors associated with poor outcomes. Methods: we randomly 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 11-2019. The cumulative risk of mortality among patients with different pathologic features were estimated using Kaplan Meier curves. Multivariable Cox regression models were built for the analysis of risk factors. Results: One hundred and thirty nine patients (Mean age, 41.6±6.9 years; 53.2% males) with non-hereditary colorectal cancer were identified. Pathology revealed tumors arising in adenoma in 61.5% of the cases (88.8% tubulovillous, 11.2% tubular adenomas). The rectum was the most common location (32.2%). The most common histologic type was invasive adenocarcinoma (86.0%). About seventy percent of the tumors were low-intermediate grade. Among patients with resected tumors, lymphovascular invasion (LVI) was present in 40.4%, perineural invasion (PNI) was present in 15.4%, intratumoral lymphocytes were present in 16.3%, and intratumoral neutrophils were present in 5.8%. About half of the resected tumors had low score tumor budding, 21.1% had Crohn’s like response, and 19.0% had tumor deposits. Microsatellite instability (MSI) accounted for 9.0% of the tumors tested for it. Twenty four percent had stage 1(T1), 11.5% (T2), 40.7% (T3), 15.9% (T4), and 8.0% (Tx). Only 29.0% received colonoscopy within 1 year after the clearing first full colonoscopy. On last follow up, 30% of the patients died. The survival of patients with tumor deposits were decreased compared to patients without tumor deposits (P=0.02) (Figure 1). With multivariate analysis, increased N stage (Hazard ratio [HR], 6.23; 95% CI, 1.45-26.77. P=0.01) and not undergoing surveillance colonoscopy (Hazard ratio [HR], 6.0; 95% CI, 2.50-14.4. P< 0.01) were associated with decreased survival. Discussion: Tumor-adjacent polyps were identified in about 60% of the cases; none of them was a sessile serrated lesion. Tumor deposits was associated with decreased survival. About 1/3 of the patients died on last follow up. Increased N stage and missing surveillance colonoscopy were associated with poor outcomes.
Disclosures: Mohamad Mouchli indicated no relevant financial relationships. Miranda Gerrard indicated no relevant financial relationships. Adil Mir indicated no relevant financial relationships. Lindsey Bierle indicated no relevant financial relationships. Shravani Reddy indicated no relevant financial relationships. Christopher Walsh 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.