TUESDAY, June 16 (HealthDay News) -- Black Americans appear to have less access to colorectal cancer specialists, which means they may be less likely to receive timely and appropriate treatments, researchers say.

In a study that analyzed population and health data from all 3,219 counties in the United States, the research team found that the higher the population of blacks in a county, the lower the number of specialists who diagnose and treat colorectal cancer. In contrast, counties with a greater population of Asian Americans were found to have more colorectal cancer specialists.

The study is in the June issue of Archives of Surgery.

"What is significant about this is that the federal government has set out a plan to eliminate disparities in health care access by 2010," the study's author, Dr. Awori J. Hayanga, a resident at the University of Michigan, said in a news release from the school.

"The structure of health care varies from county to county," Hayanga said. "Some counties have much more than they need, and others have much less than they need. There is a geographical hurdle that has to be overcome, and it has to do with the way racial groups are clustered."

Blacks are more likely than other Americans to die of colorectal cancer, the researchers noted.

In another study, published in the June issue of the Journal of the American College of Surgeons, Hayanga looked at access to surgical care by blacks and Hispanics in the United States.

It found that in counties with the highest levels of segregation, an increase in the number of black or Hispanic residents in the population was associated with a decrease in the availability and use of surgical services and greater use of emergency departments.

More information

The American Cancer Society has more about race and colorectal cancer  .

MONDAY, June 15 (HealthDay News) -- In a study of mice with lung cancer, a treatment that targeted nicotine receptors more than doubled the animals' survival time, Italian researchers say.

Nicotine plays a dual role in lung cancer. Changes in genes encoding nicotine receptors not only drive the urge the smoke, but also increase susceptibility to lung cancer. Exposure to nicotine boosts the expression of nicotine receptors, which leads to increased cell proliferation and inhibits the programmed cell death known as apoptosis.

In the new study, published in the June 15 issue of the American Journal of Respiratory and Critical Care Medicine, the compound α-CbT dampened the expression of nicotine receptors and increased apoptosis, prolonging the lives of the mice.

"This research clearly has profound clinical implications regarding the role of nicotine in stimulating lung cancer and nicotine receptor antagonists in treating the disease," said Dr. John Heffner, past president of the American Thoracic Society, in a news release from the society. Heffner, who was not involved in the research, added, "The highly addictive nature of nicotine, however, complicates patients' ability to quit smoking and avoid ongoing nicotine exposure."

Previous research has shown that it's possible to dampen the response of nicotine acetylcholine receptors (nAChRs) using an antagonist called d-tubocurarine/α-Cobratoxin (α-CbT), which specifically targeted the area most linked to increased cell growth.

In the study, researchers grafted human non-small-cell lung carcinoma (NSCLC) onto the lungs of mice and then delayed treatment, allowing the tumors to become well-established.

The mice were then divided into three groups: the untreated group; the standard chemotherapy drug group; and the α-CbT group.

Mice that were categorized as non-obese/severe combined immunodeficient (NOD/SCID) and treated with cisplatin (the standard chemotherapy agent) were found to have a 16 percent longer median survival time than untreated mice. NOD/SCID mice treated with α-CbT had an increased median survival time of 1.7-fold over the cisplatin-treated mice and 2.1-fold over untreated mice.

"The results of this study show that α-CbT, a powerful, high-affinity α-7-nAChR inhibitor, induces antitumor activity against NSCLC by triggering apoptosis," wrote Patrizia Russo of the Lung Cancer Unit of the National Cancer Research Institute in Genoa, Italy, in the news release.

Noncancerous cells did not appear to be affected by α-CbT, suggesting limited toxicity, the researchers found, but they noted that cancer cells with the most receptor binding sites seemed have the greatest treatment sensitivity.

"The goal of this research line is to explore the widest range of possibilities of intervention on the α7-nAChRs," Russo said. "We hope to move further on towards the clinical setting experimentation phase for the assessment of potentially new treatment strategies for NSCLC."

More information

The U.S. National Cancer Institute has more on non-small-cell lung cancer.

MONDAY, June 15 (HealthDay News) -- Applying the chemotherapy drug fluorouracil to skin might help improve the appearance of sun-damaged areas and reduce potentially precancerous patches, according to a small, new study.

Fluorouracil is used to treat cancers of the colon, head and neck, pancreas and other organs. Changes in skin appearance have been noted in people undergoing treatment with systemic fluorouracil, and this led to the development of a skin cream that contains the cancer drug.

The new study included 21 healthy volunteers with sun-damaged skin and actinic keratoses -- skin lesions that could develop into skin cancer -- on their faces. The participants applied 5 percent fluorouracil cream to their faces twice daily for two weeks.

The researchers said that the number of actinic keratoses declined from an average of 11.6 lesions per person to an average of 1.5 lesions. There were also improvements in aging-related damage, including wrinkling and dark skin spots.

The study, funded by Valeant Pharmaceuticals International, was published in the June issue of the journal Archives of Dermatology.

"For patients in whom a course of topical fluorouracil is indicated for the treatment of actinic keratoses, there will likely be the additional benefit of a restorative effect from sun damage; this may provide further motivation for these patients to undergo the rigorous treatment," concluded Dr. Dana L. Sachs, of the University of Michigan Medical School, and colleagues.

"It is possible that for some patients topical fluorouracil may have an important role against photo-aging," they wrote. "For others, however, it may not be cosmetically acceptable given that a standard course of therapy may last two to three weeks and the ensuring reaction can persist for several more weeks. Undoubtedly, there will be patients who desire a therapy such as topical fluorouracil for cosmetic purposes given the relatively low cost of this therapy compared with ablative laser resurfacing."

More information

The U.S. National Cancer Institute offers skin cancer prevention tips.

FRIDAY, June 12 (HealthDay News) -- Did humans lose some of their ability to ward off cancer in return for developing a more advanced brain?

That's a possibility, says a Georgia Institute of Technology researcher who found that the genes of chimpanzees are better than those of humans at apoptosis, or programmed cell death -- one of the main ways the body kills cancer cells.

John McDonald, chairman of Georgia Tech's School of Biology and chief research scientist at the Ovarian Cancer Institute, made the finding when comparing gene expression in the brain, testes, liver, kidneys and heart of chimps and humans. Chimps, which are considered human's evolutionary kin, have lower cancer rates than humans -- a fact that McDonald said has always intrigued him.

"The results from our analysis suggest that humans aren't as efficient as chimpanzees in carrying out programmed cell death," he said in a Georgia Tech news release. "We believe this difference may have evolved as a way to increase brain size and associated cognitive ability in humans, but the cost could be an increased propensity for cancer."

The findings appear online in the journal Medical Hypothesis.

More information

The U.S. National Cancer Institute has more about understanding cancer.