Biomarker for liver problems also predicts lung cancer likelihood

Call it biomarker repurposing. Researchers have identified a compound produced by the body that can flag smokers at increased risk for lung cancer--a substance long used to gauge liver function.

Dr. Xifeng Wu of the University of Texas MD Anderson Cancer Center in Houston presented the research at the annual meeting of the American Association for Cancer Research in Washington, D.C., and MedPage Today reported on the highlights.

The new biomarker in question is bilirubin, which the Mayo Clinic describes as an orange-yellow waste product generated by the breakdown of red blood cells that passes out of the body in feces and urine--a normal process. Higher-than-normal bilirubin levels have typically served as a reliable biomarker for liver problems. But this new research strongly pointed to male smokers with lower-than-normal levels of bilirubin having a greater risk of developing lung cancer versus male smokers that produced larger amounts of bilirubin.

Wu told MedPage Today that the discovery, identified from metabolic profiling and then tested successfully in a large Taiwanese cohort study of nearly 436,000 people, was a surprise. Wu and her team found that male patients with low bilirubin levels faced a 51% higher risk of developing lung cancer. They identified bilirubin as a possible biomarker after metabolic testing of 20 healthy patients, 20 with early-stage lung cancer and 20 with late-stage lung cancer, according to the story.

The quest for new lung cancer biomarkers continues in other places, too. Singaporean researchers recently linked the stem cell surface biomarker CD166 with lung cancer and then determined an enzyme biomarker that could be a potential drug target.

While more testing will be needed, a new biomarker that could predict lung cancer likelihood would give doctors a valuable tool. Its use could lead to earlier patient monitoring and treatment and the development of more targeted drugs, once the relationship between bilirubin and lung cancer is better known.

- read the MedPage Today story