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 A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital

nachricht Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München

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: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>