TUESDAY, March 25 (HealthDay News) -- The use of a less invasive form of sentinel lymph node biopsy (SLNB) during breast cancer surgery increased substantially in the United States from 1998 to 2005, researchers say. However, there are still disparities in terms of which women receive the therapy.

A team at Emory University working with the American Cancer Society found that that non-white women, women aged 72 and older, and women living in poor areas of the country were less likely to receive the SLNB staging test than those who were white, younger, or live in more affluent areas.

In women diagnosed with breast cancer, doctors check to see if the cancer has spread from the breast tissue into neighboring lymph nodes. This can be done by removing many lymph nodes in a procedure called axillary lymph node dissection (ALND) or by removing a few lymph nodes (SLNB), which is associated with easier recovery and fewer long-term problems, according to background information in the study.

In this study, researchers analyzed national data on women who had breast cancer surgery between 1998 and 2005. Clinical care guidelines were changed in 1998 to allow surgeons to use SLNB in certain patients.

The proportion of patients who had SLNB increased from 26.8 percent in 1998 to 65.5 percent in 2005, the study found.

But the researchers also found that disparities in the use of SLNB persisted during those years. For example, in 1998, 29 percent of white women received SLNB, compared with 26 percent of black women, and 35 percent of Hispanic women. By 2005, the rates were 70 percent, 64 percent, and 67 percent, respectively.

According to clinical guidelines, SNLB should only be done in centers that have experienced teams. This study didn't examine whether the disparities in access to SLNB may be related to lack of experience at certain facilities.

"The disparities that were related to receipt of SLNB in this study are particularly important in light of the clinical advantages associated with this technique. Better outcomes have been reported for patients receiving SLNB than for patients receiving ALND," the researchers wrote.

The study was published online March 25 in the Journal of the National Cancer Institute.

"Given America's track record of disparate care, I suppose we should not be surprised that racial and ethnic minorities were disproportionately deprived of another medial advance," Dr. Stephen B. Edge, of Roswell Park Cancer Institute in Buffalo, wrote in an accompanying editorial. "However, this observation is profoundly disappointing and sobering. It is yet another call for us to redouble efforts to identify and correct the root cause of disparities."

More information

The U.S. National Cancer Institute has more about SLNB.

TUESDAY, March 25 (HealthDay News) -- The effectiveness of public campaigns or efforts to prevent cancer can often be overstated in certain kinds of cancer trials because of inappropriate statistical analysis, a new report claims.

The review, published in the March 25 online issue of the Journal of the National Cancer Institute, suggests that some of the 75 group-randomized cancer trials it studied may have reported these interventions were effective when in fact they might not have been.

"We cannot say any specific studies are wrong. We can say that the analysis used in many of the papers suggests that some of them probably were overstating the significance of their findings," review author David Murray, chairman of epidemiology in the College of Public Health at Ohio State University, said in a prepared statement.

In the review, more than a third of the 75 trials contained statistical analyses that the reviewers considered inappropriate to assess the intervention being studied. Most of those studies reported statistically significant intervention effects that, because of analysis flaws, could be misleading to scientists and policymakers, the review authors stated.

"If researchers use the wrong methods, and claim an approach was effective, other people will start using that approach. And if it really wasn't effective, then they're wasting time, money and resources and going down a path that they shouldn't be going down," Murray said.

In group-randomized trials, researchers randomly assign identifiable groups to specific conditions and observe outcomes for members of those groups to assess the effects of an intervention under study.

For example, a group-randomized trial might study the use of mass media to promote cancer screenings and then assess how many screenings result among groups that receive different kinds of messages.

The review is not an indictment of the study design. Murray is a proponent of such trials, and authored a 1998 textbook on the subject, "Design and Analysis of Group-Randomized Trials."

"We're not trying to discourage people from using this design. It remains the best design available if you have an intervention that can't be studied at the individual level," he said.

In analyzing the outcomes of such trials, researchers should take into account any similarities among group members or any common influences affecting the members of the same group, Murray said. However, the review found that the common ground among group members was often not factored into the final statistical analysis.

"In science, generally, we allow for being wrong 5 percent of the time. If you use the wrong analysis methods with this kind of study, you might be wrong half the time. We're not going to advance science if we're wrong half the time," said Murray, who is also a member of the Cancer Control Program in Ohio State's Comprehensive Cancer Center.

The review identified 75 articles published in 41 journals that reported intervention results based on group-randomized trials related to cancer or cancer risk factors from 2002 to 2006. Thirty-four of the articles, or 45 percent, reported the use of appropriate methods to analyze the results. Twenty-six articles, or 35 percent, reported only inappropriate methods used in the statistical analysis. Eight percent of the articles used a combination of appropriate and inappropriate methods, and nine articles had insufficient information to even judge whether the analytic methods were appropriate or not.

The use of inappropriate analysis methods is not considered willful or in any way designed to skew results of a trial, Murray noted.

Murray and his colleagues call for investigators to collaborate with statisticians familiar with group-randomized study methods, and for funding agencies and journal editors to ensure that such studies show evidence of proper design planning and data analysis.

More information

The American Cancer Society has more about prevention and early detection of cancer  .

MONDAY, March 10 (HealthDay News) -- A cutting-edge drug for brain cancers may place pediatric patients at risk for bone damage and stunted growth, an animal study suggests.

The new red flag concerns a signal transduction inhibitor (STI) medication known as "HhAntag", a drug developed to treat medulloblastoma brain tumors by short-circuiting tumor growth on the molecular level. The fear is that a therapy proven safe and highly successful among adults may pose a unique set of risks to young patients.

"Within just two days of treatment with HhAntag, we found a permanent shortening of bones and an alteration of joint structure among young mice," noted study co-author Tom Curran, deputy scientific director of the Stokes Research Institute at the Children's Hospital of Philadelphia.

"It's a little scary," he added. "Of course, the drug works well for about one-third of brain cancers. However, this is the first time it's really been tested in young animals. And the pathways that are targeted by this treatment are very active and important in developing children. So, we have a serious problem."

Curran and his team are publishing their findings in the March issue of Cancer Cell.

The authors noted that medulloblastoma is the most common pediatric central nervous system cancer. Although traditional non-STI treatments -- such as surgery, radiation and chemotherapy -- offer a five-year survival rate in almost four out of five children, such therapies often provoke severe side effects such as movement disorders and cognitive impairments. Those treatments are also far less effective among children under the age of 3 or among those whose disease has spread.

To date, HhAntag has achieved non-toxic results among adults -- targeting the so-called "hedgehog" pathway and shutting down a signaling mechanism critical to cancer cell proliferation. However, that same pathway regulates bone development.

Concerned that the drug might throw the baby out with the bathwater among younger patients, the researchers focused on mice between 10 and 14 days old, all genetically engineered to have cancer.

Several doses of HhAntag were tested over two-week treatment periods. The highest dose -- 100 mg/kg offered twice daily -- was found to be an ideal recipe for killing cancer.

However, X-rays revealed that after just two days, the therapy provoked widespread skeletal, cartilage and joint abnormalities, as well as impaired growth and weight loss. Even after cessation of treatment, the damage was irreversible.

Curran believes that the harsh STI consequences observed in young mice would be similarly manifested in children -- though to what degree remains unclear.

"So, for children we could potentially try to figure out how to deliver these drugs to the brain tumor and not the bones," he said. "But that will require a lot more research, which is unlikely to be performed by the pharmaceutical companies who wouldn't benefit financially, because the potential patient pool amounts to just a few hundred children per year for this kind of cancer."

"Without this research, we think the drug will only be useful for a subset of young patients," Curran noted. "Children with recurrent brain tumors, for example. Because, unfortunately, children who have relapsed don't live very long, and the side effects become irrelevant."

Dr. John S. Yu, co-director of the Comprehensive Brain Tumor Program at Cedars-Sinai Medical Center's Maxine Dunitz Neurosurgical Institute in Los Angeles -- shared Curran's concern.

"This study brings up a cautionary note for the long-term well-being of the young cancer patient," he said. "It certainly has significant repercussions for children with medullablastoma and other tumors that may be treatable with an expectation for a long survival. But, of course, I agree that for those children with a very long short life expectancy of a year or less, this problem would have less of an impact. In those cases, the treatment would certainly be worth the risk."

More information

For additional information on STIs and other targeted cancer drug therapies, visit the Hughes Cancer Center.

TUESDAY, March 4 (HealthDay News) -- In patients who had surgery for pancreatic cancer, adding the chemotherapy drug gemcitabine to chemoradiation prolonged survival, but the improvement was not statistically significant, a new study finds.

Among patients who have surgery to remove pancreatic cancer, there is a 50 percent to 85 percent rate of local relapse and a five-year survival rate of less than 20 percent, according to background information in the study.

This makes the combination of added postoperative chemotherapy and radiation an important consideration. Previous research has shown that gemcitabine is more effective than the drug fluorouracil at improving patient outcomes.

This study examined whether the addition of gemcitabine to the supplemental treatment of fluorouracil chemoradiation improved survival in patients who had a portion of their pancreas removed as a treatment for pancreatic cancer.

During the study, the 451 patients received either chemotherapy with gemcitabine (221) or with fluorouracil (230) for three weeks prior to chemoradiation therapy and for 12 weeks after chemoradiation therapy (with fluorouracil).

Among the 388 patients with pancreatic head tumors, those in the gemcitabine group had a median (midpoint) survival of 20.5 months and a three-year survival rate of 31 percent, compared to 16.9 months and 22 percent among those in the fluorouracil group. The rates of certain level (grade 4) of hematologic (abnormalities in blood cell counts) toxicity were 1 percent in the fluorouracil group and 14 percent in the gemcitabine group.

There were no differences in neutropenia (a blood disorder), infection, or in the ability to complete chemotherapy or radiation therapy.

"The addition of gemcitabine to (supplemental) fluorouracil-based chemoradiation was associated with a survival benefit for patients with resected pancreatic cancer, although this improvement was not statistically significant," the study authors concluded.

The study was published in the March 5 issue of the Journal of the American Medical Association.

More information

The American Cancer Society has more about pancreatic cancer  .