LATEBREAKER
Cancer
Carcinogenic Metals and Colorectal Cancer Incidence: Pilot Results from the Louisville Environmental Assessments Pilot Study (LEAPS) in Colorectal Cancer Natalie DuPre* Natalie DuPre Lu Cai Jason Xu Allie Jin Olufunmilayo Babarinde Jeevan Adhikari Sandy Kavalukas
Background: Colorectal cancer (CRC) is the 3rd most commonly diagnosed cancer in the US, with the CDC recently reporting that Kentucky has the highest age-standardized CRC rate despite high CRC screening. Cadmium (Cd) and arsenic (As) are known human carcinogens for certain cancers. However, most epidemiologic studies on As and Cd with CRC are within occupational settings considering CRC mortality outcomes and not CRC incidence.
Methods: The Louisville Environmental Assessments Pilot Study (LEAPS) in CRC is a clinical case-control initiated in August 2023. We consented CRC cases and controls who were undergoing procedures related to CRC or screening from an urban hospital. Participants completed a detailed questionnaire and provided urine and blood samples. As and Cd were measured in biospecimens of eight non-smoking participants using inductively coupled plasma mass spectrometer (ICP-MS). We compared metal concentrations (ng/mL) in 3 cases and 5 controls with unequal variance t-tests.
Results: Within the LEAPS-CRC population (28 CRC cases; 52 controls), CRC risk factors were more prevalent in CRC cases than controls. The standard deviations (SD) were 0.32 ng/mL for urinary Cd, 0.16 for blood Cd, 6.8 for urinary As, and 0.46 for blood As. On average, urinary Cd was 0.16 ng/mL higher in CRC cases (i.e. 0.46 vs 0.30 ng/ml) than controls, corresponding to half of a SD. Blood Cd concentrations were 0.155 ng/mL higher in CRC cases than controls (i.e. 0.28 vs 0.12 ng/ml), that corresponds to ~1.0 SD. Urinary As was 0.9 ng/mL higher in CRC cases than controls (i.e. 6.64 vs 5.69 ng/ml). As expected, differences were not statistically significant due to small sample sizes.
Conclusion: Preliminary data suggests that carcinogenic metals in biospecimens may be associated with CRC incidence in non-occupationally exposed and non-smoking populations. The ongoing LEAPS-CRC investigation holds the potential to determine whether carcinogenic metals may be novel CRC risk factors.