OBJECTIVES: Severe burns place patients in a compromised state, especially those with pre-existing chronic diseases such as malignancy. Due to improvements in detection and treatment, cancer mortality has declined significantly, leaving a growing population of cancer survivors. Therefore, we wondered whether pre-existing cancer diagnoses influence patient outcomes following burn injury. METHODS: 46,275 patients with a neoplasm diagnosis prior to experiencing a burn injury were identified using the TriNetX research network. Two control groups were organized: 1) cancer patients without burns and 2) burn patients with no history of cancer. The test group included patients with a pre-existing cancer diagnosis who received a subsequent burn injury. Outcomes included death, sepsis, nutritional deficiency, eating disorder, immunodeficiency, and depression. Odds ratios were calculated with 95 % confidence intervals. RESULTS: Of the nearly 10 million cancer patients, 0.45 % experienced a burn injury after diagnosis. Compared to propensity-matched burned patients without cancer, burned patients with a previous cancer diagnosis had increased odds of developing sepsis (2.013, 1.895-2.138), nutritional deficiency (1.874, 1.58-2.221), immunodeficiency (5.584, 4.85-7.06), eating disorder (2.384, 1.947-2.918), and depression (1.772, 1.695-1.853). The odds ratios of sepsis (1.718, 1.612-1.83), nutritional deficiency (1.963, 1.593-2.418), immunodeficiency (1.265, 1.098-1.459), eating disorder (2.569, 2.077-3.177), and depression (1.538, 1.468-1.611) were increased when compared to cancer patients without burn injury. Burned patients with a previous neoplasm of hematologic origin fared worse in the odds of developing the mentioned outcomes compared to those with solid neoplasms. Lastly, burned patients with any previous neoplasm who later received chemotherapy and/or radiation suffered worse outcomes than those who never received such treatment. CONCLUSION: Patients who developed neoplasms before receiving a burn injury demonstrated considerable increases in odds of poor outcomes. Increased odds of developing poor outcomes were greater in those with hematologic neoplasms and those who received chemotherapy or radiation treatment.