Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Low levels of serum bilirubin spell higher lung cancer risk for male smokers

08.04.2013
Study shows metabolite biomarker could improve spiral CT screening, help detect disease early

Elevated levels of bilirubin in the blood get attention in the clinic because they often indicate that something has gone wrong with the liver. Now researchers have found that male smokers with low levels of the yellow-tinged chemical are at higher risk for lung cancer and dying from the disease.

A team led by researchers at The University of Texas MD Anderson Cancer Center reported its findings in a late-breaking abstract at the AACR Annual Meeting 2013 in Washington, D.C.

"Our study indicates male smokers with low levels of bilirubin are a high-risk group that can be targeted with smoking cessation help, low-dose spiral CT screening of their lungs and other preventive measures," said senior author Xifeng Wu, M.D., Ph.D., professor and chair of MD Anderson's Department of Epidemiology and the Betty B. Marcus Chair in Cancer Prevention.

Lung cancer usually is diagnosed at a late stage, when tumors are inoperable and treatments largely ineffective. The overall five-year survival rate is 15 percent, but it falls to 5 percent for stage 3 lung cancer patients and 1 percent for those with stage 4 disease.

Spiral CT scans catch cancer early, biomarker could reduce false positives

The National Lung Screening Trial found that low-dose spiral computed tomography screening reduces mortality among heavy smokers by 20 percent. However, 95 percent of growths found by spiral CT are false positives, a barrier to large-scale screening.

"Validated biomarkers are urgently needed to improve risk prediction for lung cancer and to reduce false positives, shifting the balance toward more effective and efficient CT screening for cancer detection," Wu said.

The researchers started with an objective analysis of levels of metabolites — substances produced during metabolism. Bilirubin is produced during the breakdown of old blood cells.

They analyzed 60 samples divided into three groups known as "trios" — normal controls, early stage and late stage non-small cell lung cancer patients. The top three metabolites were validated in two more groups of 50 and 123 trios.

When bilirubin emerged as the most significant metabolite, another validation study was done in a prospective cohort of 435,985 people with 208,233 men in Taiwan.

Men were divided into four groups according to their serum bilirubin levels. Lower bilirubin level was associated with significantly higher rates of both lung cancer incidence and mortality.

In the Taiwanese cohort, the incidence rate per 10,000 person-years in men was 7.02 for those in the lowest bilirubin quartile (.68 mg/dL or less), compared to 3.73 in the highest quartile of bilirubin level (1.12 mg/dL or more). The mortality rate per 10,000 person-years was 4.84 for the lowest level compared with 2.46 in the highest bilirubin quartile.

Next step: Establish a risk prediction model in heavy smokers

Bilirubin makes sense as a protective agent because of its anti-oxidant, anti-inflammatory and anti-proliferative effects. "It's plausible that bilirubin protects against lung cancer by scavenging free radicals and carcinogens associated with smoking," said study presenter Fanmao Zhang, a doctoral candidate in epidemiology.

Indeed, a Belgian study showed that bilirubin in the high normal range lowered cancer mortality in men. A study in the United Kingdom showed higher bilirubin levels in the normal range were associated with lower risks of chronic obstructive pulmonary disease, lung cancer and all-cause mortality. Neither of those studies stratified their analysis of bilirubin by smoking status.

"We expected that bilirubin might be protective, but our finding that bilirubin levels affect only smokers was somewhat of a surprise," Wu said. "Our discovery that low levels increase lung cancer risk is unique."

Smokers in the two middle cohorts of bilirubin levels also had higher lung cancer risk than those in the highest quartile. As an objective risk index for lung cancer and all-cause mortality, low levels of bilirubin should send an urgent message to quit smoking, said Chi Pang Wen, M.D., Ph.D., co-lead author from National Health Research Institutes, Taiwan.

The next step, Wu said, is to evaluate the predictive value of serum bilirubin in heavy smokers and to establish a risk prediction model that incorporates bilirubin and other biomarkers with clinical and epidemiological data to improve the efficiency of lung cancer risk prediction.

Co-authors Dong Liang, Ph.D., of the Texas Southern University Department of Pharmacy Health Programs; Jian Gu, Ph.D., Wong-Ho Chow, Ph.D.,Yuanqing Ye, Ph.D., Xia Pu, Ph.D., Michelle A. Hildebrandt, Ph.D., and Maosheng Huang, all of MD Anderson's Department of Epidemiology; Heath Skinner, M.D., Ph.D., of MD Anderson's Department of Radiation Oncology; Min Kuang Tsai of the National Health Research Institute, Taiwan; and Chwen Keng Tsao of MJ Health Management Institution, Taipei, Taiwan; and Christopher Wen, M.D., U.S. Department of Veterans Affairs Long Beach Healthcare System

This project was supported in part by grants from the National Cancer Institute of the National Institutes of Health (P50 CA070907), the MD Anderson Research Trust and Center for Translational and Public Health Genomics, Duncan Family Institute for Cancer Prevention and Risk Assessment.

Scott Merville | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Health and Medicine:

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>