Tag Archive for: biomarkers

Biomarkers allow scientists to identify certain diseases from a simple biological sample like urine, breath, or even feces. Volatile organic compounds (VOCs) are the byproducts of metabolic processes associated with cancer, necrosis, or other metabolic changes. Scientists have now identified a new biomarker associated with both colorectal cancer (CRC) and adenoma (noncancerous tumor) that can be used for detection.

The cross-sectional study included 24 newly diagnosed CRC patients, 24 patients with adenomas, and 32 individuals who had a normal colonoscopy between July 2017 and July 2020. Individuals with normal colonoscopies and those with adenomas had fecal samples collected before and after their colonoscopy. Samples were requested from CRC patients 3-4 weeks after diagnosis and before treatment.

Of the 60 VOCs identified, only 3 showed different peaks between CRC and the control groups: p-cresol, 1H-indole, and 3(4H)-DBZ. There was a statistically significant difference between p-cresol peak values in each group with the greatest difference between CRC and the control group. This was also the same for 3(4H)-DBZ. However, 1H-indole did not have a significant difference between the study groups.

After adjusting for sex, age, and body-mass index (BMI), the researchers found that only CRC was associated with increased p-cresol and 3(4H)-DBZ, and p-cresol seemed to be the best possible predictor of CRC. A combination of p-cresol and 3(4H)-DBZ “is also optimistic as a combined biomarker” according to the study authors.

p-cresol was also abundant among patients with adenomas compared to healthy controls. This was also the case after adjusting for age, sex, and BMI.

Although more work needs to be done to determine what processes produce these VOCs, these associations can launch a new set of studies to confirm its use in a clinical setting. Other biomarkers have been identified that can  predict CRC occurrence and mortality. Overall, the ability to better detect CRC and precancerous adenomas play an important role in global prevention efforts. A better understanding of the biological processes involved in these diseases is crucial for those efforts to be successful.


Kaylinn Escobar is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.

Photo credit: National Cancer Institute on Unsplash

Interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-a) are inflammatory biomarkers that are capable of activating Janus kinase signaling pathways, nuclear factor signaling pathways, and C-reactive protein (CRP) transcription. CRP tests are commonly used in cancer care to predict prognosis, as activation of the Janus kinase and nuclear factor signaling pathways can  aid in tumor expansion and metastasis. Additionally, high-sensitivity CRP tests (hsCRP) are able to identify small amounts of CRP in blood samples.

One recent study assessed the association between these inflammatory biomarkers (IL-6, TNF-a, and hsCRP) with CRC recurrence and mortality in 1,494 stage III colorectal cancer (CRC) patients. This was the largest study assessing the relationship between these inflammatory biomarkers and CRC survival as of yet. 

While the study recruited a diverse sample of individuals, the final sample was overwhelmingly White (82.3%) and non-Hispanic (94.5%). Future studies should prioritize racial diversity to more accurately assess this association, as racial disparities exist in CRC diagnoses and outcomes. 

Researchers collected plasma samples from participants 3-8 weeks following their surgery but prior to chemotherapy. These plasma samples were then analyzed for IL-6, TNF-a, and hsCRP. The primary study outcome was disease-free survival and secondary outcomes were recurrence-free survival and overall survival. Participants who had higher concentrations of IL-6, TNF-a, and hsCRP were more likely to have CRC recurrence. High levels of these biomarkers were also found to be associated with an increased risk of mortality.

This study reveals that there is a significant association between inflammation following stage III diagnosis and poor CRC outcomes. Clinicians can utilize this information to better monitor their patients and improve CRC outcomes with evidence-based treatment solutions.

Emma Edwards is a Colorectal Cancer Prevention Intern with the Colon Cancer Foundation.