WEDNESDAY, Oct. 12 -- Scientists announced Wednesday that they have succeeded in sequencing the full genome of the naked mole rat, an exceptionally long-lived and cancer-resistant rodent.

While that might not sound like headline news, scientists say the findings could provide insights into human aging and risks for malignancy.

"If we can understand the genetic adaptations, we may be able to find treatments which can change the human into a more long-lived species," said Vadim N. Gladyshev, senior author of the study published online Oct. 12 in the journal Nature.

Another expert, Dr. Greg Enders, associate professor of medicine at Fox Chase Cancer Center in Philadelphia, expressed enthusiasm. "This paper is an interesting piece of work [and may provide] useful hypotheses into how they can have such longevity and not cancer."

However, these ideas are still "all hypothetical in the future and very controversial," added Gladyshev, director of the Center for Redox Medicine at Brigham and Women's Hospital and Harvard Medical School in Boston.

On average, the naked (meaning hairless) mole rat lives more than 30 years, or almost 10 times as long as a typical mouse. Not only are they healthier for a longer period of time than other rodents, they live underground in the dark, are cold-blooded and can reproduce until they die. They do have poor vision, however.

"They have many unusual traits, and all of them are important in some way," said Gladyshev. "They are long-lived, live in low-oxygen conditions, are resistant to cancer, [and] don't maintain a stable body temperature."

In analyzing the genome of this remarkable mammal, the researchers noted some similarities with other mammals. The number of genes is about the same in naked mole rats (22,561), humans (22,389), mice (23,317) and rats (22,841).

Many of the naked mole rat genes are also located in the same place on the chromosome as human, mice and rat genes, the research revealed.

But in the naked mole rat, unlike in humans, there were few differences in how the genes were expressed at age 4 and at age 20.

There were eight cancer-related genes, one of which was the protein P16. "This is one of the major human tumor suppressor proteins, and it's clear that the naked mole rat has that protein and upregulates it more rapidly in certain situations that probably prevent cancer formation," Enders said.

The naked mole rat also produces less insulin than humans, has adapted its circulatory system and metabolism to deal with a low-oxygen environment and has few of the receptors that detect bitter tastes. These adaptations may eventually yield clues about living in extreme conditions, the researchers noted.

This research is just a start, Gladyshev said. "We and others probably will now carry out experimental studies on some of these findings to really understand in detail what this data means."

SOURCES: Vadim N. Gladyshev, Ph.D., director, Center for Redox Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston; Greg Enders, M.D., Ph.D., associate professor of medicine, Fox Chase Cancer Center, Philadelphia; Oct. 12, 2011, Nature, online

WEDNESDAY, Oct. 12 -- Black Americans who have surgery for stage 2 and stage 3 colon cancer have worse overall and recurrence-free survival rates than whites, a new study finds.

Researchers analyzed data from nearly 15,000 black and white colorectal cancer surgery patients who took part in 12 clinical trials conducted in North America between 1977 and 2002. All the patients received the same adjuvant -- or additional -- colon cancer therapy after surgery.

Over five years, black patients had a 4.6% lower overall survival rate and a 3.7% lower recurrence-free survival rate.

Black patients, however, did have a similar recurrence-free interval, or the time in which they were cancer-free before seeing their cancer return, as whites.

The survival differences between black and white patients are mostly likely due to factors unrelated to a patient's response to post-surgical treatment, said Greg Yothers, of the U.S. National Surgical Adjuvant Breast and Bowel Project Biostatistical Center, and colleagues.

"Biological differences, differences in general health, and disparities in health care outside the clinical trial are possible explanations for these findings," the researchers wrote in a journal news release.

Staging indicates how far cancer has spread.

The study is published Oct. 12 in the Journal of the National Cancer Institute.

The findings are consistent with other studies published in the last decade, Dr. Olufunmilayo Olopade, director of the Center for Clinical Cancer Genetics & Global Health at the University of Chicago, and colleagues wrote in an accompanying editorial.

They said future studies must include information on patients' socio-demographic status, tumor biology and other health conditions. They added that primary care of colon cancer survivors should be improved and monitored in order to learn more about differences in survival after cancer recurrence, and that race-specific enrollment targets may be required for trials examining genetic markers.

Despite overall improvements in colorectal cancer survival in the United States, five-year survival rates between 1999 and 2005 were 57% for blacks and 68% for whites.

-- Robert Preidt

SOURCE; Journal of the National Cancer Institute, news release, Oct. 12, 2011

WEDNESDAY, Oct. 12 -- The risk of developing deadly esophageal cancer for patients with a condition known as Barrett's esophagus is significant, but not as dire as once reported, a large new Danish study suggests.

Analyzing records from Denmark's entire population of 5.4 million people, researchers determined that those with Barrett's esophagus -- a disorder often brought on by chronic reflux -- are about 11 times as likely as those without it to develop esophageal cancer, a substantial drop from the 30- or 40-factor increase reported in prior research.

This particularly lethal form of cancer, which grew in prevalence in the United States six-fold between 1975 and 2001, occurs more often in older white men and has risk factors that include obesity and frequent heartburn. Patients with Barrett's esophagus, which sometimes produces abnormal cells, are typically monitored with frequent endoscopies, tests in which thin tubes with cameras are inserted into the esophagus and stomach to detect changes in cells lining the organs.

Study author Dr. Peter Funch-Jensen, a professor of surgery at Hamlet Hospital and Clinical Institute at the University of Aarhus, said the results indicate that Barrett's esophagus patients can probably undergo fewer invasive endoscopies. Patients with low- or high-grade cell dysplasia -- abnormal cells that are often a pre-cursor to cancer -- remain at much higher risk, however.

"The clinical implication is that patients with Barrett (without dysplasia) should probably only be investigated [with endoscope] the first year and hereafter no further endoscopy is necessary, unless new symptoms appear," Funch-Jensen said. "Esophageal cancer has increased in incidence during the last years ... if it increases very much further, the situation may change. Also, it is a possibility that we will discover other risk factors that will pinpoint a subset of patients that may benefit from surveillance."

The study is published Oct. 13 in the New England Journal of Medicine.

Using records from the Danish Pathology Registry and the Danish Cancer Registry from 1992 through 2009, Funch-Jensen and his team identified about 11,000 patients with Barrett's esophagus and analyzed their data for an average of five years. While those with the condition were found to have a much higher chance of developing esophageal cancer compared to the general population, only 0.12% go on to develop it each year -- much lower than the assumed risk of 0.5%, according to the study.

The 197 cases of esophageal cancer diagnosed among all patients known to have Barrett's esophagus represented only 7.6% of all such cases. During the same period, 2,602 new cases of esophageal cancer were diagnosed in the general population.

U.S. experts said the results of the study weren't surprising, though they probably wouldn't affect the standard of care established for Americans with Barrett's esophagus, who tend to undergo frequent endoscopies.

"I don't think based on this one study alone, we can actually make policy changes and certain societal recommendations about screening," said Dr. Anthony Starpoli, a gastroenterologist at Lenox Hill Hospital in New York City. "For me, what this does is let me tell the patient, 'I think you have a little less to worry about.' I think we can reassure our patients to allay the fear."

Dr. David Bernstein, chief of gastroenterology at North Shore University Hospital in Manhasset, N.Y., praised the study as "important and interesting" but emphasized that the cancer risk is still significant in those with Barrett's esophagus.

"We really don't have good guidelines in this country for screening patients with Barrett's for cancer, unless we find dysplasia," he said. "Whenever we mine a database, we're looking at numbers, not patient charts, so we don't necessarily have the full story. I think we'd need to have a similar type of study done here."

SOURCES: Peter Funch-Jensen, M.D., D.M.Sc., professor, surgery, Hamlet Hospital and Clinical Institute, University of Aarhus, Denmark; Anthony Starpoli, M.D., gastroenterologist, Lenox Hill Hospital, New York City; David Bernstein, M.D., chief, division of gastroenterology, North Shore University Hospital, Manhasset, N.Y.; Oct. 13, 2011, New England Journal of Medicine

WEDNESDAY, Oct. 12 -- Changes in the bacteria in a person's mouth might signal the onset of pancreatic cancer, preliminary research reveals.

The small study suggests that it eventually might be possible to screen for the deadly disease simply by analyzing a patient's saliva, as the presence or absence of certain oral bacteria seems to indicate a higher risk.

The observation, however, raises the question: Does pancreatic cancer prompt changes in an individual's oral bacterial landscape, or are such shifts actually driving the onset of disease?

"We don't yet know," cautioned study author Dr. James J. Farrell, an associate professor with the UCLA Center for Pancreatic Diseases at the University of California, Los Angeles. "This is a small study, and just the first step. But certainly this is the first indication of its kind that an analysis of oral flora can find differences that could point to a mechanism where pancreatic cancer might develop."

"At the same time," added Farrell, "what led us to explore this in the first place is the search for the holy grail: a test that would identify malignancy early on, because the problem with pancreatic cancer is that the vast majority of patients present at a very late stage. Only about 15% are diagnosed at a point where they're eligible to have surgery. So for most the only option is chemotherapy, which has a very poor response rate. So, there's a dire need for early detection. And this work could, down the road, lead to a noninvasive and widely applicable way to get just that."

Farrell and his colleague report their findings in the current online issue of the journal Gut.

Pancreatic cancer is typically very aggressive, with only about 5% of patients living five years beyond their diagnosis. Apple co-founder Steve Jobs died last week of the disease.

The research team set out to explore a possible oral connection to pancreatic cancer by comparing the saliva content of 10 cancer patients -- whose disease had not spread -- with that of 10 healthy individuals of similar age and gender.

The oral cavity hosts upward of 700 different species of bacteria, some of which are linked to periodontitis, a bacteria-driven inflammatory disease.

The cancer patients carried 31 species of bacteria not present in the mouths of the healthy participants. At the same time, those with cancer lacked 25 other species that were present among the disease-free pool.

A second oral comparison was made between 28 cancer patients, 27 patients with chronic pancreatitis (thereby at high risk for cancer), and 28 healthy individuals.

The result: Two bacterial species --Neisseria elongata and Streptococcus mitis -- were much more likely to be found in the mouths of healthy people than those with cancer. Scanning for levels of these two bacteria enabled the research team to accurately distinguish between cancer patients and healthy participants more than three-quarters of the time (80%).

In reverse, levels of another species -- Granulicatella adjacens -- were higher among those with disease.

Differences in bacterial composition also existed among patients with chronic pancreatitis, relative to healthy people.

"Although any advance in the arena of early detection is important, what is perhaps more important is the idea that oral floral changes are part of the cause of pancreatic cancer," Farrell said. "And although we don't yet know, in fact most of the pieces of data already out there looking at oral hygiene -- mostly with respect to cardiac disease -- would suggest that the interplay between oral bacteria and our cells can lead to disease.

"And this idea opens up a whole new arena for exploration," he added. "Because it would mean, in theory, that we could have a whole new target for cancer intervention."

Dr. Michael Choti, a professor of surgery and oncology at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University in Baltimore, described the UCLA team's work as "interesting," but cautioned that more follow-up is needed.

"We're not at the point where people should go and get saliva swabs," he said. "And it's not clear whether there's anything causative here. It's way too early to know that.

"But clearly there's a lot of interest now in trying to develop ways to detect early stage pancreatic cancer," Choti added. "And there is precedent for this approach with other types of malignancies. What we don't yet know, however, is whether these changes in bacteria occur early enough in the development of cancer to be a useful tool for early detection. It's possible the changes occur later in the course of disease, in which case not only would it not be causative but it would not help at getting to an early diagnosis."

"But the work is certainly promising," he said. "And worthy of further research."

SOURCES: James J. Farrell, M.D., associate professor, UCLA Center for Pancreatic Diseases, UCLA David Geffen School of Medicine, Los Angeles; Michael Choti, M.D., professor, surgery, oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore; 2011, Gut, online

TUESDAY, Oct. 11 -- Nearly 90% of U.S. women believe mammograms are vital to their health and well-being, according to a new national poll of 1,000 voters.

The research commissioned by the American College of Radiology also revealed that by having routine mammograms, women gain a sense of control over their own care.

"I'm encouraged that poll results show that nearly nine in 10 women voters are getting regular mammograms. However, I think we need to continue to stress to women and health care providers that mammography saves lives," Dr. Barbara S. Monsees, chair of the American College of Radiology (ACR) Breast Imaging Commission, said in an ACR news release.

The death rate for breast cancer has dropped by more than 30% since 1990 with the help of mammography, according to the release.

"Mammography is the best tool available to screen for breast cancer. At present, there is nothing to replace it. We need to make sure that women get the information they need to make informed decisions and to protect and enhance access to life-saving mammograms," Dr. Debra L. Monticciolo, president of the Society of Breast Imaging, concluded in the news release.

Although many major medical organizations recommend that all women aged 40 and older get yearly mammograms, research reveals that the number of U.S. mammography facilities is on the decline.

According to U.S. Food and Drug Administration figures cited in the news release, there are currently 223 fewer mammography facilities and 1,331 fewer mammography scanners in the United States than there were in July 2007.

-- Mary Elizabeth Dallas

SOURCE: American College of Radiology, news release, Sept. 27, 2011