Reassessing colorectal cancer recurrence in solid organ transplant recipients: Implications for revised management guidelines.

3620 Background: Patients with solid organ transplants (SOT) are at an increased risk of developing secondary malignancies, including colorectal cancer (CRC). However, the influence of SOT and associated immunosuppression on recurrence risk following definitive treatment is poorly understood. This study characterizes the recurrence risk of CRC in a cohort of patients that developed CRC after SOT. Methods: Patients treated within the Johns Hopkins and University of Wisconsin medical systems meeting study criteria were identified using SlicerDicer Epic reports. Manual chart review was performed to determine treatment course, patient/disease characteristics, and whether or not their disease recurred. Results: Fifty-two patients with CRC following SOT were identified, including those who had liver (n = 12), kidney (n = 26), combined liver and kidney (n = 5), combined pancreas and kidney (n=4), lung (n = 4), and heart (n = 1) transplants. Among these patients, 30 were male and 22 were female. Ten patients had recurrent CRC after curative intent treatment. Recurrence rates were as follows: 1 of 10 (10.00%) patients with stage I CRC, 5 of 12 (41.67%) patients with stage II CRC, and 4 of 18 (22.22%) patients with stage III CRC. The overall CRC recurrence rate in the cohort was 32.26%. Conclusions: In summary, a multi-institution retrospective cohort study of patients with CRC diagnosis following SOT demonstrated higher than traditionally expected recurrence rates in patients with stage I and II disease when compared to patients diagnosed with CRC without history of SOT. Further multi-institutional studies are warranted to validate this finding. If confirmed, this would suggest transplant status may alter adjuvant treatment decisions and warrant future prospective studies in this patient population. Study cohort variables stratified by CRC staging. Stage at Diagnosis Avg. Age at Time of Diagnosis Sex Race Transplant Type Avg. Time from Transplant to CRC Diagnosis (months) Recurrence Rate Avg. Time to CRC Recurrence (months) Avg. Overall Survival (months) Stage 0 72.00 1 Female 1 Caucasian 1 Liver 34.73 0.00% N/A 4.70 Stage I 57.50 6 Male, 4 Female 3 African American, 6 Caucasian, 1 Pacific Islander 5 Kidney, 2 Liver, 2 Pancreas/Kidney, 1 Lung 159.73 10.00% 51.78 54.42 Stage II 56.33 7 Male, 5 Female 3 African American, 9 Caucasian 7 Kidney, 1 Liver, 2 Liver/Kidney, 2 Pancreas/Kidney 172.35 41.67% 29.87 61.34 Stage III 62.39 12 Male, 6 Female 3 African American, 14 Caucasian, 1 Asian 9 Kidney, 4 Liver, 3 Liver/Kidney, 1 Lung, 1 Heart 148.76 22.22% 18.03 52.15 Stage IV 52.18 5 Male, 6 Female 2 African American, 9 Caucasian 5 Kidney, 4 Liver, 2 Lung 148.83 N/A N/A 18.70 All Stages 58.08 30 Male, 22 Female 11 African American, 39 Caucasian, 1 Asian, 1 Pacific Islander 26 Kidney, 12 Liver, 5 Liver/Kidney, 4 Pancreas/Kidney, 4 Lung, 1 Heart 154.14 32.26% 27.33 46.72