The results were reported at the 35th Congress of the European Society for Medical Oncology (ESMO) in Milan, Italy.
The link between smoking and cancer has been established for decades, explained Dr Yuk Ting Ma from the Cancer Research UK Institute of Cancer Studies, Birmingham, who presented the results. Smoking is the single biggest cause of cancer in the world, and years of research have confirmed that carcinogenic substances in tobacco smoke can damage DNA.
Scientists have also suspected that smoking causes so-called epigenetic changes, such as methylation, which alter gene expression without causing changes to the actual DNA sequence.
"Until now, however, there has been no direct evidence that smoking induces DNA methylation in humans," Dr Ma said. "Cross-sectional surveys restricted to patients with cancer have revealed that aberrant methylation of several tumor suppressor genes is associated with smoking. But such surveys cannot distinguish those epigenetic changes that are a consequence of the disease process from those which are directly attributable to smoking."
In a study funded by Cancer Research UK, the British team set out to clarify the link between smoking and methylation in a cohort of 2,011 healthy young women aged 15-19 who were originally recruited as part of a study of pre-cancerous changes to cells of the cervix.
"For this particular study we have identified all the women from that cohort who had normal smears and who also tested negative for human papillomavirus throughout follow-up," Dr Ma explained. "In this subgroup of disease-free women we have then tested the cervical smears of all the women who first started to smoke following study entry for p16 methylation, and compared them to women who were never smokers."
The researchers selected this group of women to ensure there were no potential cofounding factors for the detection of p16 methylation in otherwise healthy young women.
The particular gene the researchers were studying was p16, a so-called tumor suppressor gene. When it is methylated, this gene's normal tumor-suppressing function is inactivated.
"DNA methylation is a type of epigenetic change that can result in tumor suppressor genes being inactivated," said Dr Ma. "Methylation of p16 has been frequently associated with the development of cancer in many parts of the body."
Because the women were all taking part in a study of cervical neoplasia, Dr Ma used cells from cervical smears to test for methylation of p16. Her group found that women who took up smoking during the study were more than three times as likely (odds ratio of 3.67) to acquire p16 methylation.
"Our study showed that compared with never-smokers, women who first started to smoke during follow-up had an increased risk of acquiring methylation of p16," Dr Ma said. "Our choice of study design and our study population allowed us to reveal, for the first time, the relationship between starting to smoke and the subsequent appearance of an epigenetic change."
The results provide evidence that smoking does induce DNA methylation, Dr Ma said. "The next step is now to show that women who acquire such smoking-induced methylation have an increased risk of developing malignancy."
Notes to Editors
Contact the ESMO Press Office at email@example.com to find out:How to follow press briefings remotely via toll-free dial-in
The Congress full program is available at http://www.esmo.org/events/milan-2010-congress/program.html
Media registrationOn-site registration is possible at the Press Registration Desk. You will be asked for your press card and a letter of assignment.
About the European Society for Medical Oncology
The European Society for Medical Oncology (ESMO) is the leading European professional organization committed to advancing the specialty of medical oncology and promoting a multidisciplinary approach to cancer treatment and care.
ESMO's mission is to advance cancer care and cure through fostering and disseminating good science that leads to better medicine and determines best practice. In this way ESMO fulfils its goal to support oncology professionals in providing people with cancer with the most effective treatments available and the high-quality care they deserve.
The ESMO community is a powerful alliance of more than 6,000 committed oncology professionals from over 100 countries. As a trusted organization with 35 years of experience and over 500 expert officers, ESMO serves its members and the oncology community through: a brand of excellence in post-graduate oncology education and training; leadership in transforming evidence-based research into standards of cancer care in Europe; dedicated efforts to foster a more favorable environment for scientific research; innovative international platforms to share expertise, best practices and disseminate the most up-to-date scientific research to as wide an audience as possible.
ESMO's scientific journal, Annals of Oncology, ranks among the top clinical oncology journals worldwide. ESMO events are the meeting place in Europe for medical oncologists to update their knowledge, to network and to exchange ideas.
To find our more about our Society, please visit: www.esmo.org
Vanessa Pavinato | EurekAlert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
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...
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...
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...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
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...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy