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Acid reflux linked to cancer in throat-
(Yahoo News- 10/08/2007)
A U.S. study warns that preventing recurring acid reflux is critical because the acid can cause cells in the esophagus to become more prone to cancer.
Scientists at the University of Texas Southwestern Medical Center in Dallas and the Dallas Veterans Affairs Medical Center say the acid bath can cause normal cells in the esophagus to change into tougher, more acid-resistant cells, a condition called Barrett’s esophagus that results in cells becoming more at risk to cancer.
Researchers compared telomere length -- the ending sequences in DNA strands -- and telomerase activity -- an enzyme that adds specific DNA sequence repeats at the end of DNA strands -- in biopsy specimens from 38 patients with gastroesophageal reflux disease and 16 control patients.
Each time the acid-bathed cells divide, the telomeres at the end of DNA become shorter and when they become too short, the cell can no longer divide and other cells might infiltrate the and those cells may be more likely to generate the acid-resistance that makes them more likely to turn cancerous, suggested the study published in the American Journal of Physiology -- Gastrointestinal and Liver Physiology.
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Gullet cancer link seen with obesity-(Yahoo
News-
10/10/2007)
Highly obese people are six times likelier to develop cancer of the gullet than people of healthy weight, according to a study published on Thursday in the British journal Gut.
The probe, carried out in Australia, looked at 793 people with oesophageal cancer, who were compared with 1,580 counterparts matched for age and place of residence.Risks of developing this cancer were higher among individuals who had gastric acid reflux, which has long been associated with such tumours.
But another big risk factor was obesity.
Those with a body mass index (BMI, a measure of fat) of 40 or more were six times more at risk than people with a BMI of between 18.5 and 25, which is deemed to be a standard for good health.
A combination of obesity and acid reflux boosted the risk by a factor of 16.
The risk held true, even when smoking and high alcohol consumption, which are also culprits in cancer of the gullet, were taken into account.
The paper speculates that obesity triggers an increase in levels of insulin and this in turn boosts the production of another hormone called insulin-like growth factor.
These hormones are known to stimulate cell proliferation and inhibit a process called apoptosis, in which a faulty cell is prompted to commit suicide. Both conditions favour cancer development.
However, only further research will say whether this theory or rival hypotheses is right, say the authors, led by David Whiteman, a professor at the Queensland Institute of Medical Research in Brisbane.
BMI is calculated by taking one's weight in kilograms and dividing it by the square of the height in metres.
People who are overweight have a BMI of between 25 and 30, while beyond 30 is considered obese. A BMI of 40 and above is considered extreme obesity, according to World Health Organisation (WHO) definitions.
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Zinc Deficiency Linked To Increased Risk Of Less–Common Form Of
Esophageal Cancer-(Science Daily-23/02/2005)
Researchers at the National Cancer Institute (NCI), part
of the National Institutes of Health, have found that zinc deficiency in
humans is associated with an increased risk of developing esophageal
squamous cell carcinoma, an often-fatal form of esophageal cancer that has
about 7,000 cases a year. NCI researchers used a novel approach to measure
the concentration of zinc and other elements directly in the esophageal
tissue. Their results, appearing in the February 15, 2005, Journal of the
National Cancer Institute, showed an inverse relationship between tissue
zinc concentration and subsequent risk of esophageal squamous cell
carcinoma.
Dietary deficiency of zinc, an essential mineral, has been associated
with esophageal cancer in rodents. So far, though, examining this
association in humans has been hampered by the difficulty of measuring
zinc levels in the body through traditional methods. “Measuring zinc
levels in the blood is not very sensitive,” noted lead author Christian
Abnet, Ph.D., of NCI’s Cancer Prevention Studies Branch. “Because zinc is
maintained in a state of equilibrium, just like body temperature, the
readings will tend to be similar. Calculating zinc from intake of meat and
other dietary sources isn’t very sensitive either since other compounds,
like phytates in whole grains, will inhibit zinc absorption.”
Abnet turned to a different technique: X-ray fluorescence spectroscopy,
which involves bombarding a sample with high-intensity X-rays, causing the
elements in the sample to fluoresce, or glow, with a characteristic energy
signature. “This allowed us to measure element concentrations directly in
the tissue of interest,” said Abnet, “so it should be the best indicator
of the effects of zinc or other metals.”
Esophageal tissue samples were obtained from a population in Linzhou,
China, that was followed from 1985 through 2001. People in this region are
at high risk for squamous esophageal cancer and tend to consume little
meat and a lot of whole grain, and therefore are more likely to be zinc
deficient. An earlier publication estimated that residents of this region
get only 62 to 72 percent of the U.S. dietary recommendations for zinc,
whereas most Americans meet current dietary recommendation levels.
A subset of the population underwent endoscopy with biopsy in 1985, and
the NCI team, with the aid of Barry Lai, Ph.D., at Argonne National
Laboratories, Argonne, Ill., examined these specimens. They measured zinc,
copper, iron, nickel and sulfur levels in samples from 60 subjects who
developed esophageal squamous cell carcinoma during the 16 year follow-up
and from 72 histology-matched subjects at the start of the study who did
not develop the disease.
The average tissue zinc concentration was significantly lower in
subjects who developed esophageal cancer than in control subjects (44 ng/cm2
compared to 57 ng/cm2). When the researchers ranked the study participants
by quartiles based on zinc concentration, they found that those in the
highest quartile had a 5-fold lower risk of developing esophageal cancer
than those in the lowest quartile. Overall, 90 percent of subjects in the
highest quartile were alive and cancer-free after 16 years, while only 65
percent of the subjects in the lowest quartile were alive and cancer-free.
There were no consistent associations with cancer risk for any of the
other elements studied.
These findings establish an initial connection between zinc and
esophageal squamous cell carcinoma in humans, although further research is
needed to ensure this association is more than a local phenomenon in an
area of extreme zinc deficiency. However, Abnet believes the technique
itself holds great promise for future element studies. “X-ray fluorescence
spectroscopy has many advantages,” said Abnet. “You can apply it to most
elements and you only need a tiny tissue sample. Also, it doesn’t damage
the tissue, so you can make multiple measurements on one sample.” Abnet
also noted that they successfully measured samples collected and embedded
in paraffin
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Sodas
Raise Cancer Risk, U.S. Study Finds-(Reuters-17/05/2004)
Carbonated drinks
may raise the risk of esophageal cancer, a usually fatal disease, researchers
reported. Several studies presented at a meeting of cancer and gastrointestinal
experts in New Orleans showed that what people eat and drink could affect
a range of cancers. "This research supports the widespread medical recommendations
for healthy eating," said Dr. Lee Kaplan of Massachusetts General Hospital
and Harvard Medical School in Boston.
A team at Tata Memorial
Hospital in India found a strong correlation between the rise in per capita
consumption of carbonated soft drinks in the past 50 years and a documented
increase in rates of esophageal cancer in the United States. Team members
studied U.S. Department of Agriculture data to find that per capita consumption
of carbonated drinks rose by more than 450 percent, from 10.8 gallons
on average in 1946 to 49.2 gallons in 2000. And over the past 25 years,
the incidence rates of esophageal cancer have risen by more than 570 percent
in white American men. Esophageal cancer affected 13,900 U.S. men and
women in 2003 -- more than 10,000 men -- and killed almost all of them,
according to the American Cancer Society. The number of esophageal cancer
cases clearly followed the rise in intake of carbonated soft drinks, the
researchers found.
That could be coincidence,
but they also found research that showed a possible biological basis for
the effect. Carbonated soft drinks cause the stomach to distend, which
in turn causes the gastric reflux associated with esophageal cancer. The
researchers found similar trends worldwide. Countries with per capita
annual consumption of more than 20 gallons of fizzy soft drinks also had
rising rates of esophageal cancer. "The surprisingly strong correlation
demonstrates the impact of diet patterns on health trends," Dr. Mohandas
Mallath, who led the study, said in a statement.
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Surgical
skill increases survival for oesophageal cancer surgery-(Yahoo News-08/04/2004)
From the Federation
of European Cancer Societies: Surgical skill increases survival for oesophageal
cancer surgery "Resection of the oesophagus for cancer should no longer
be an operation with a high mortality rate provided experienced surgeons
are involved as part of a multidisciplinary team", according to Mr Subhajit
Dutta Roy, Clinical Research Fellow at the Surgical Research Unit, Leighton
Hospital, Crewe in the United Kingdom. Mr Dutta Roy was speaking at the
12th Congress of the European Society of Surgical Oncology in Budapest.
Oesophageal cancer
is closely associated with alcohol consumption and tobacco smoking. The
UK has one of the highest incidences of oesophageal cancer in Europe and
each year there are around 4,200 deaths from the disease. The mainstay
of treatment for oesophageal cancer is surgery to remove the oesophagus,
a procedure known as 'oesophagectomy'. However, the procedure is known
for having a relatively high mortality rate. Mr Dutta Roy and his colleagues
used the Hospital Episodes Statistics database to examine the outcome
of 6,950 oesophagectomies in England over a four year period from 1997
- 2001. They found that in those hospitals with high oesophagectomy case-loads
there was a corresponding, and statistically significant, improvement
in operative survival. Mr Dutta Roy acknowledged that in-hospital mortality
can arise from a number of factors, and assessing outcome measures for
all types of complex surgical procedures is inherently difficult. "However,
the statistics show a clear survival benefit where experienced surgeons
perform the procedure", he added.
These results mirror
those found in other studies and further suggest that surgical skill is
a major factor in successful outcome of surgical procedures for a range
of cancers, and may also suggest a potential beneficial effect of centralization
of oesophageal cancer surgery in England. There are currently no specialist
oesophageal centers in the UK and Mr Dutta Roy cautions against steps
to develop them on the basis of these results alone. "Centralizing the
resources for one specific procedure in a specialist center may, in fact,
make matters worse as better results from high volume centres lack specificity
and may be due to inherent structures and processes in place in 'bigger'
hospitals". "It would make more sense to develop specialized, regional
centers for all complex surgical procedures", said Mr Dutta Roy.
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