Navigation Links
Smoking-related colorectal cancer in older women is associated with molecularly defined DNA changes
Date:6/30/2010

Smoking, an established risk factor for colon cancer, may induce specific epigenetic changes and gene mutations that may be involved in the development of colon cancer, according to an online study published June 29 in the Journal of The National Cancer Institute.

Cigarette smoking is a risk factor for colorectal cancer, with a recent meta-analysis estimating that people who currently smoke or smoked in the past are 18% more likely to develop colorectal cancer than non-smokers. But few studies have looked at the effect smoking may have on the specific molecular pathways of colorectal cancer. This study investigated how smoking may cause colorectal cancer at the molecular level.

To explore the molecular pathways of smoking-related colorectal cancer, Paul J. Limburg, M.D., of the Mayo Clinic, and colleagues, evaluated smoking patterns among women in the Iowa Women's Health Study (IWHS), who were between the ages of 55 and 69 years. They looked at the age at which women started smoking, the average number of cigarettes per day and per year.

The researchers sent a questionnaire to the 98,029 women enrolled in IWHS as of January 1986, to which 43% or 41,836 women responded. Non-smokers constituted 66% of the respondents, with 34% identifying themselves as active or former smokers.

The researchers found that there was only a modest association between cigarette smoking and overall colorectal cancer incidence but that smoking was strongly associated with a certain subtype of colorectal cancer, namely tumors that had high levels of microsatellite instability (MSI), epigenetic changes (alterations that do not affect the DNA sequence), and BRAF mutations.

The authors write that the results "have provided additional support that cigarette smoking is a risk factor for colorectal cancer but further indicate that the smoking-related risk may pertain to specific molecularly defined colorectal cancer subtypes that develop through epigenetically mediated carcinogenic pathways."

Furthermore, they write: "These findings indicate that epigenetic modification may be functionally involved in smoking-related colorectal carcinogenesis."

The sub-type of colorectal cancer that emerged in the study is more prevalent among older women, making them a rich sample pool for studies. However, for that same reason, the authors caution against generalizing the results to the general public.

The study could have important clinical implications: "Emerging colorectal cancer screening technologies, such as stool assays that are based on methylation markers [signs of epigenetic changes] might be particularly informative for patients with a history of prolonged tobacco use," the authors write.

In an accompanying editorial, C. Richard Boland, M.D. and Ajay Goel, Ph.D., of Baylor University Medical Center, write: "The most important message to take from the study by Limsui et al. is that colorectal cancer is a complex collection of diseases and that causation might be different for each of the categories. Cigarette smoking is associated with a specific subset of these tumors."

Boland and Goel point out that although there is a lot to understand in terms of how smoking interacts with other environmental factors, such as diet, in causing colon cancer, "the methylation pathway is particularly interesting because epigenetic changes, unlike point mutations and chromosomal rearrangements, are potentially reversible. Our task now is to understand how to translate these findings into improved screening and prevention-based strategies."


'/>"/>

Contact: Kristine Crane
jncimedia@oxfordjournals.org
301-841-1285
Journal of the National Cancer Institute
Source:Eurekalert

Related medicine news :

1. Smoking-related colorectal cancer in older women is associated with molecularly-defined DNA changes
2. Hydrophobic proteins: Potential biomarkers for colorectal cancer
3. Is it safe for endoscopic piecemeal mucosal resection in treating large sessile colorectal polyps?
4. Bacteria as a predicter of colorectal cancer
5. Exploring gender differences in colorectal cancer screenings
6. FDG-PET/CT plays a definite role in detecting colorectal cancer recurrences
7. Investigators examine colorectal cancer screening methods among diverse populations
8. Researchers show that nitric oxide-donating naproxen can boost colorectal cancer prevention
9. Association of fiber and colorectal cancer risk differs depending on dietary assessment method
10. UAB researchers find 4 biomarkers important in colorectal cancer treatment prognosis
11. Hispanics live in areas with limited capacity for colorectal cancer screening
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... Viejo, California (PRWEB) , ... June 27, 2016 , ... ... are fully customizable inside of Final Cut Pro X," said Christina Austin - CEO ... another unique style. Final Cut Pro X users can now reveal the ...
(Date:6/27/2016)... ... June 27, 2016 , ... ... strategic partnership with Connance, a healthcare industry leader providing predictive analytics to ... technology combine to provide health systems, hospitals and ambulatory surgical centers with ...
(Date:6/27/2016)... Overland Park, KS (PRWEB) , ... June 27, 2016 , ... ... leader in retailers of Eyeglasses . , Millions of individuals in the United ... life, eyeglasses have become a way to both correct vision and make a fashion ...
(Date:6/26/2016)... ... 26, 2016 , ... On June 10-11, 2016, A Forever Recovery, a holistic ... World’s Longest Breakfast Table in Battle Creek, MI, where the rehabilitation facility is located. ... some of the world’s leading providers of cereal and other breakfast foods. Its residents ...
(Date:6/26/2016)... ... June 26, 2016 , ... PawPaws brand pet supplements ... that was developed to enhance the health of felines. The formula is all-natural and ... main herbs in the PawPaws Cat Kidney Support Supplement Soft Chews are ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ ) ... Improvements Act of 1976, as amended ("HSR"), with respect ... Nasdaq: CPXX ) expired effective June 24, ... As previously announced on May 31, 2016, Jazz Pharmaceuticals ... which Jazz Pharmaceuticals has commenced a tender offer for ...
(Date:6/24/2016)... HILL, N.C. , June 24, 2016 /PRNewswire/ ... healthcare decisions and regulators/payers have placed more emphasis ... new environment, patient support programs in the pharmaceutical ... for patients, medications. Consequently, pharmaceutical companies are focusing ... ensure they are providing products and services that ...
(Date:6/24/2016)... CAMBRIDGE, Mass. , June 24, 2016 /PRNewswire/ ... the Spaulding Rehabilitation Network,s Dean Center for ... of Physical Medicine and Rehabilitation, MIT Hacking Medicine, ... Center for Innovation, today announced the five finalists ... Hackathon for Lyme disease.  More than 100 scientists, ...
Breaking Medicine Technology: