Researchers have demonstrated on Mar. 19 that RNA biomarkers linked to colorectal cancer, including CDH1, can be detected in community wastewater using a proof-of-concept approach. The study, published in the Journal of Epidemiology & Community Health, outlines a method for identifying colorectal cancer-related signals at the community level through wastewater surveillance systems.
This research is significant as it suggests a new way to monitor colorectal cancer (CRC) risk across populations without relying solely on individual participation in traditional screening methods such as colonoscopies or stool tests. Early detection of CRC is crucial for improving health outcomes, and this approach could help address gaps in screening coverage, especially in low-resource settings.
For the first time, scientists have identified specific human ribonucleic acid (RNA) biomarkers associated with colorectal neoplasia in community wastewater. These markers are based on those used in multitarget stool RNA assays for early CRC detection among adults aged 45 and older. The presence of biomarkers like cadherin 1 (CDH1) highlights the potential utility of this method to complement existing screening programs and support targeted prevention efforts as CRC rates rise among younger populations.
The study involved collecting wastewater samples from four residential sewer sheds—three identified as high-incidence CRC clusters and one control region—using data from a specialized care center and statewide cancer registries. Researchers extracted RNA from these samples and quantified biomarker expression using digital polymerase chain reaction (PCR). They found that GAPDH, a housekeeping gene, averaged about 52 copies per microliter across all samples, confirming consistent extraction. Notably, CDH1 levels were highest in the cluster with known patients from the care center.
Although sampling was limited to a single day with few samples and no statistical testing performed, results showed detectable levels of CRC-associated RNA biomarkers in all communities studied. The pronounced CDH1 signal in one cluster suggests that wastewater monitoring may reflect local disease burden but does not establish causality.
The findings indicate that non-invasive monitoring through wastewater could eventually inform public health policy by identifying high-risk areas with minimal patient participation. Researchers recommend expanding future studies to include more sites and repeated sampling while integrating findings with registry data to refine spatial mapping of CRC risk. Addressing ethical and privacy considerations will also be essential before broader implementation.
