P.W. Murangiri1, V. Perim2, V. Vudatha3, C. Mcleod2, J. Trevino3, A. Carter2, A. Gillis2 1Oakwood University, Huntsville, Alabama, USA 2University Of Alabama at Birmingham, Department Of General Surgery, Birmingham, Alabama, USA 3Virginia Commonwealth University, Division Of Surgical Oncology, Richmond, VA, USA
Introduction: Colorectal cancer (CRC) is the third most common cancer worldwide. Different environmental and biological factors such as diet, smoking status, and the microbiome have been shown to affect this cancer development and survival. Preliminary pre-clinical data suggests amphetamine use may alter the GI tract microbiome and may be associated with CRC. However, the effect of amphetamine use on the clinical development and outcomes of colorectal cancer remains unknown. Therefore, this study aims to investigate the use of amphetamines among colorectal cancer patients in the Deep South of the United States.
Methods: A retrospective cohort study was conducted from 2010 to 2024 at a single NCI-designated cancer center in American Deep South. We identified all patients diagnosed with CRC based on ICD codes: C180-189. Patient demographics and clinical characteristics were analyzed from electronic medical records, including race, age, gender, Charlson comorbidity index (CCI), cancer stage, and overall survival. Patients were stratified based on the use of prescription amphetamine, methylphenidate (control due to difference in biologic mechanism), or neither. Descriptive statistics and bivariate tests, including ANOVA, Kruskal-Wallis, Chi-square, and Kaplan-Meier analysis with log-rank test, were performed to compare characteristics across groups.
Results: A total 2,585 patients with CRC were analyzed with 35 (1%) in the amphetamine group, and 22 (1%) in the methylphenidate group. Overall the mean age at diagnosis was 61.2 years (SD: 13.1) with a 50% female representation. Among these patients, 65% (n=1,674) were white, 28% (n=676) were black, and 90% (n=2,341) resided in Alabama. The median CCI was 2 (IQR: 1-3). In the amphetamine cohort, 62% (n=21) were female and 94% (n=32) white. In the methylphenidate cohort, 57% (n=13) were female and 96% (n=21) were white. The amphetamine and methylphenidate cohorts were younger than those taking neither (52.5 (SD) and 59.9 (SD) vs. 61.4 (SD), respectively), p<0.001. The amphetamine and methylphenidate cohorts were more likely to be diagnosed with late stage (III/IV) colorectal cancer compared to those taking neither with incidence of 69%, 82%, and 57%, respectively (p=0.03). All three groups had the majority of CRC diagnosis made in the past decade, with 80%, 55%, and 64% of diagnoses occurring from 2013 to 2023, respectively (p=0.3). In Kaplan-Meier analysis, survival from diagnosis was not significantly different between groups (p=0.33).
Conclusion: At a single cancer center, CRC rates have increased in the past decade. One percent of patients diagnosed with CRC were identified to have used amphetamines. These patients were younger and had more advanced disease compared to controls. Future prospective studies should explore the mechanisms by which amphetamine use affects colorectal cancer outcomes.