WEDNESDAY, April 23 (HealthDay News) -- A protein that stops the spread of breast cancer tumors in mice can predict which malignancies might spread, a new study suggests.

The gene, called bromodomain protein (Brd4), when added to breast cancer cells in mice, produced a unique gene signature, which was also detected in human breast cancer patients.

"We have identified that this particular gene seems to be associated with outcomes in breast cancer," said lead researcher Kent W. Hunter, a senior investigator at the U.S. National Cancer Institute. "This gene may be something we want to investigate in more detail."

Understanding how the new gene functions may lead to a better understanding of what makes breast cancer metastasize, Hunter said. "This will help identify patients who will have a better or worse outcome," he added.

The report was published in this week's issue of the Proceedings of the National Academy of Sciences.

In the study, Hunter's team inserted the gene for the Brd4 proteins into mouse breast cancer tumor cells that are known for their ability to metastasize.

However, tumor cells that contained Brd4 produced smaller tumors that did not metastasize as readily. In addition, Brd4 changed many other genes, resulting in a unique genetic signature.

The researchers then mapped the signature genes to corresponding human genes, and compared the human Brd4 signature with patient data from five large groups of breast cancer patients.

In all five groups, those patients who had the Brd4-positive signature lived longer and had a lower incidence of metastatic tumors, the researchers found. This indicates that the Brd4 gene expression signatures could accurately predict the severity of breast cancer, the researchers said.

These findings may lead to new treatments, Hunter said.

"We may not only be able to find a prognostic signature, but we can identify other genetic elements that are driving prognosis, so we may also be able to develop additional therapeutic strategies," Hunter said. "We may be able to find new drugs or strategies to improve quality of life and extend life span."

One expert doesn't think this gene makes a contribution to predicting the prognosis of breast cancer.

"This is a marker study looking at a novel gene and its expression, and suggests that the gene expression may predict outcome in node-negative, estrogen-positive breast cancer," said Dr. Harold J. Burstein, an assistant professor of medicine at Dana-Farber Cancer Institute, Brigham and Women's Hospital and Harvard Medical School.

"There are already multiple, commercially available gene expression array tests such as Oncotype DX, MammaPrint, with more extensive clinical support for similar patients," Burstein said. "Most investigators believe that multiple gene assays are more informative than single gene assays."

"Finally, the clinical validation in this experience is drawn from small sets of patients, and the strength of the data suggest modest, if any, real contribution for this gene," Burstein said.

More information

For more on breast cancer, visit the U.S. National Cancer Institute.

WEDNESDAY, April 23 (HealthDay News) -- Scientists say they may have discovered how tumors develop in the stomach, a finding that could lead to new treatments for gastric cancer.

In a study done on mice, scientists at the Melbourne Branch of the International Ludwig Institute for Cancer Research (LICR) found that blocking the signaling pathway of the IL-11 protein -- either through genetic manipulation or with medications -- would prevent certain inflammation, hyperplasia (an abnormal increase in the number of cells), and tumor formation in pre-clinical models of stomach cancer.

Stomach cancer, the second most common cause of cancer-related deaths worldwide, has been shown previously to be correlated with chronic inflammation.

The findings were published online April 22 in The Journal of Clinical Investigation.

The study shows that IL-11 promotes chronic inflammation and the formation of tumors in the stomach by increasing activation of the Stat3 protein, a known player in inflammation-associated carcinogenesis. Excessive Stat3 activity is often found in gastric and other types of cancer. The underlying cause of the Stat3 issue had previously been unknown.

"The clear link between inhibition of IL-11/Stat3 activity and suppression of gastric tumorigenesis that we identified supports the further development of pharmacologic agents that target these molecules for the treatment of gastric and potentially other cancers," study author Matthias Ernst, from the LICR Melbourne Branch, said in a prepared statement. "We believe that we have a very relevant model in our hand for the preclinical assessment of such compounds as well as for the identification of potential markers that may ultimately help in the early detection of disease."

More information

The American Cancer Society has more about stomach cancer  .

TUESDAY, April 22 (HealthDay News) -- Skin lesions larger than six millimeters in diameter are more likely than smaller lesions to be melanoma skin cancer, a new study suggests.

The finding supports the current widespread use of diameter guidelines to screen for melanoma, researchers say.

This "ABCDE" screening method is based on five features characteristic of melanoma: asymmetry, border irregularity, color variegation, diameter larger than six millimeters, and changes in a lesion.

However, some experts have argued that strict adherence to the diameter guideline will cause doctors to miss smaller melanomas, according to background information in the study.

In this study, researchers at the New York University School of Medicine, New York City, studied more than 1,300 patients undergoing biopsies for 1,657 pigmented skin lesions or markings suggestive of melanoma. Of those lesions, 804 (48.5 percent) were larger than six millimeters in diameter and 138 (8.3 percent) were diagnosed as melanoma.

Invasive melanomas (which have penetrated deeper into the skin) were diagnosed in 13 of 853 lesions (1.5 percent) that were six millimeters or smaller in diameter and in 41 of the 804 (5.1 percent) of lesions that were larger than six millimeters. In situ melanomas (those that remain in the skin's outer layers) were diagnosed in 22 of the 853 (2.6 percent) of lesions six millimeters or smaller and in 62 of the 804 (7.7 percent) of lesions larger than six millimeters.

"With each one-millimeter diameter range from 2.01 to six millimeters, the proportion of melanomas did not vary significantly, remaining stable at 3.6 percent to 4.5 percent," the study authors wrote. "However, we observed a nearly 100-percent increase in the proportion of melanomas when comparing the 5.01- to six-millimeter category (4.3 percent) to the 6.01- to seven-millimeter category (8.3 percent)."

The study was published in the April issue of the journal Archives of Dermatology.

"We recommend that a diameter criterion of larger than six millimeters remain a part of the ABCDE criteria," the researchers concluded. "We do not recommend downward revision of the D criteria at this time. In the United States, rates of melanoma and nonmelanoma skin cancers have markedly increased, and skin biopsy rates have more than doubled in 20 years. In an era that demands greater data to support clinical decision making, the ABCDE criteria are valuable evidence-based guidelines to aid physicians in decisions regarding the biopsy of pigmented lesions of the skin."

More information

The American Academy of Dermatology has more about skin cancer  .