Primary Colorectal Lymphoma: Institutional Experience and Review of a National Database

BACKGROUND: Primary colorectal lymphoma is rare, representing 0.2% to 0.6% of all colorectal cancers. Because of its low incidence and histologic variety, no treatment guidelines exist. OBJECTIVE: The purpose was to report the experience of primary colorectal lymphoma in an institutional and a national cohort. DESIGN: This was a retrospective cohort study. SETTINGS: The study was conducted with institutional data composed of 3 tertiary referral centers and national data. PATIENTS: Patients with primary colorectal lymphoma were identified within the Mayo Clinic (1990-2016) and the Surveillance, Epidemiology, and End Results database (1990-2014). MAIN OUTCOME MEASURES: Primary outcomes were overall and 5-year survival. RESULTS: For the institutional cohort (N = 82), 5-year survival was 79.9%. Five-year survival was higher for rectal (88.4%) than for colon tumors (77.2%; p = 0.004). On multivariable analysis, age <50 years was associated with higher overall survival (p = 0.04). Left-sided colon masses and aggressive histological subtypes were associated with worse survival (0.04 and 0.03). No effect of treatment modality on survival was noted. For the national cohort (N = 2942), 5-year survival was 58.4%. Five-year survival for rectal tumors was 61.0% and 57.8% for colon tumors. On multivariable analysis, factors associated with improved survival were age <70 y, (p < 0.0001), female sex (p = 0.005), right-sided masses (p = 0.02), and diagnoses after 2000 compared with 1990-1999 (p < 0.0001). Aggressive pathology (p < 0.0001) and stage III or stage IV presentation compared with stage I (p = 0.02 and p < 0.0001) were associated with worse survival. LIMITATIONS: The institutional cohort was limited by sample size to describe treatment effect on survival. A major limitation of the national cohort was the ability to describe treatment modalities other than surgery, including chemotherapy and/or no additional treatment. CONCLUSIONS: Poorer survival was noted in elderly patients and in those with aggressive pathology. An overall survival advantage was seen in women in the national cohort. Currently, optimal strategies should follow a patient-centered multidisciplinary approach. See Video Abstract at http://links.lww.com/DCR/A807.