THURSDAY, Jan. 1 (HealthDay News) -- In a finding that could help doctors fine-tune breast cancer treatments even further, a new study confirms that there are genes that increase the likelihood that the disease will spread throughout a woman's body.

Scientists from the National Cancer Institute (NCI), building upon earlier research, found in both mice and human breast tumor samples that a certain gene signature predicted the chance of metastasis. Many experts have believed that metastasis is primarily the result of non-inherited mutations in cancerous tissue.

"Our earlier studies clearly established that inherited factors also play an important role in metastatic progression and can help distinguish which tumors have a propensity to metastasize," study author Kent W. Hunter, head of the NCI's Metastasis Susceptibility Section in the Laboratory of Cancer Biology and Genetics, said in an NCI release. "Hopefully, in the future, we will be able to determine which women are more likely to have a tumor that would metastasize, and we could then tailor therapy specifically for them, avoiding the use of harsh treatments for those with a low probability of metastasis."

The researchers first discovered a gene signature in mice that raised the risk of breast cancer metastasis in mice by 20-fold. They then found the corresponding human gene signature, and it predicted relapse or recurrence in four of five breast cancer patients.

"Our study provides additional evidence of the role of inherited genes in human breast cancer progression," Hunter said.

The study was published in the Jan. 1 issue of Cancer Research.

More information

For more on breast cancer metastasis, go to the University of Michigan Comprehensive Cancer Center.

WEDNESDAY, Dec. 24 (HealthDay News) -- A new, closer look at data on Caesarean section births in the United States suggests that the actual number of unnecessary surgical deliveries is far lower than previously thought.

When looking at birth certificates alone, it appears the number of C-sections being performed in the United States on women who have no risk factors is almost 60 percent. But government experts who analyzed birth certificates and hospital discharge data found the actual number of such deliveries was closer to 4 percent.

"You can't use the birth certificate alone to determine whether or not a woman is at risk for primary Caesarean delivery," said study author Emily Kahn, an epidemiologist with the U.S. Centers for Disease Control and Prevention's division of reproductive health.

The finding are published in the January issue of the journal Obstetrics and Gynecology.

Nearly one in three babies in the United States was delivered by C-section in 2005, according to the National Center for Health Statistics. That rate is the highest ever, according to background information in the study. The rate of primary Caesareans has increased sharply, while the rate of vaginal delivery after a primary C-section has dropped dramatically.

Trying to assess why the rate has increased, some researchers have turned to birth certificate data to get a population-based estimate of the number of unnecessary C-sections. If the birth certificate says there was "no indicated risk," it appears that those women had Caesareans for no discernable reasons.

Kahn said she and her colleagues were concerned that measuring unnecessary C-sections this way might lead to a large number of these surgeries being classified as unnecessary when, in fact, there were risk factors present to either the mother or baby that necessitated a C-section.

The CDC researchers sifted through data on 565,767 births from women who were considered at low risk for needing a C-section. The women were all 37 weeks' to 41 weeks' pregnant when they went into labor and had singleton pregnancies. All of the women delivered in Georgia hospitals between 1999 and 2004.

More than 70,000 of these women ended up having a Caesarean delivery, and almost 41,000 were listed on the birth certificate as having no risk factors. Yet, in the hospital discharge data, nearly 90 percent of these women had a risk factor listed.

Overall, 58.3 percent of birth certificates suggested no risk factors. But when the researchers pooled the data and combined both birth certificate data and hospital discharge data, they found the rate of Caesareans with no reported risk factors at just 3.9 percent.

Kahn said there are several possible reasons for this discrepancy. One is that the main purpose of a birth certificate is simply to record the birth. Birth certificates aren't completed by physicians, but instead rely on worksheets filled out by the mother. And, she said, hospital discharge data is used to bill the insurance companies and doctors must be very detailed on these reports to get paid, which might make them more accurate.

"Doctors don't touch birth certificates," said Dr. Miriam Greene, an obstetrician at New York University Langone Medical Center and author of the book Frankly Pregnant. "The person who writes up the birth certificate might not be knowledgeable about all the risk factors for C-section, and they see the baby is fine and may think there was no issue."

Kahn said the data from this study suggest that "women who are having primary Caesareans, by and large, do have some sort of risk factor or medical condition that could lead to a Caesarean, though we can't tell on an individual basis."

A lot of the reasons Caesareans are performed are out of a woman's control, but Greene said you can likely reduce your risk by making sure you're well-nourished without gaining too much weight during pregnancy, going to all of your prenatal visits, taking prenatal vitamins and participating in regular exercise.

More information

The March of Dimes has more on the reasons for a C-section.

MONDAY, Dec. 15 (HealthDay News) -- Blocking proteins produced by the oncogene MYC can stop the spread of ovarian cancer, researchers say.

An oncogene is a gene that has the potential to help cause cancer.

In up to 60 percent of human ovarian tumors, MYC is overly active. This causes the ovarian cells to produce excessive c-Myc, a protein regulator of other genes involved in cell growth, which leads to proliferation of the cancer cells.

University of California, Berkeley, researchers halted the spreading in lab cultures of human ovarian cancer cells with amplified MYC by using RNA interference (RNAi) to block c-Myc protein. They then used small interfering RNA (siRNA) to halt L-Myc and N-Myc proteins, a process that halted the growth of the non-amplified MYC tumors.

The therapies had no effect on lab cultures of normal ovarian surface epithelial cells, leading them to theorize that the RNAi and siRNA treatments are effective only when the MYC genes are abnormally active.

The findings are scheduled to be presented Monday at the American Society for Cell Biology annual meeting, in San Francisco.

More information

The National Ovarian Cancer Coalition has more about ovarian cancer.

MONDAY, Dec. 8 (HealthDay News) -- Women who suffer the most severe form of heart attack are twice as likely as men to die in the hospital, a new study finds.

The study of more than 78,000 people treated for heart attacks at 420 U.S. hospitals between 2001 and 2006 found the same overall in-hospital death rate for men and women.

But 10.2 percent of women with a STEMI heart attack died, compared to 5.5 percent of men with the same diagnosis, said the report in the Dec. 9 issue of the journal Circulation.

"We believe that a part of it may be related to the fact that women are undertreated," said study lead author Dr. Hani Jneid, an assistant professor of cardiovascular medicine at Baylor College of Medicine in Houston. "There is evidence across the board of undertreatment."

"We obviously could not assess the appropriateness of the treatments," Jneid added. "But the results point to the fact that there might be some sex-related disparity in treatment that needs to be addressed by physicians."

STEMI is short for ST-elevation myocardial infarction, a name derived from the heartbeat pattern seen on an electrocardiogram. A STEMI heart attack usually is caused by complete blockage of a coronary artery, which means that more heart muscle dies than if there is only partial blockage.

While in theory "there is no intrinsic reason why there should be a difference" in survival rates between the sexes, there are several possible explanations, said Dr. Gregg C. Fonarow, a professor of cardiovascular medicine at the University of California, Los Angeles, and an author of the report. Those explanations may start with the symptoms reported by people having heart attacks and then go on to the treatment they receive, he said.

"Women when presenting with a heart attack tend to be older and have other comorbid conditions [health problems]," Fonarow said. "But even when we adjusted for that, we found a 12 percent difference."

Also, "women present more atypically," he said. "They are less likely to have sternal chest pain or pressure, just general symptoms like shortness of breath or other symptoms that are non-specific."

But there clearly was a difference in the treatment given men and women, the study found. Women were 14 percent less likely to receive early aspirin, 10 percent less likely to be given beta blocker drugs, 25 percent less likely to receive reperfusion therapy to restore blood flow, and 13 percent less likely to have artery-opening angioplasty within 90 minutes of arrival at the hospital.

The American Heart Association has started a program called "Mission: Lifeline" that's designed to educate people about the symptoms of a heart attack so they can seek treatment quickly and also "enable hospitals to make quicker diagnoses," Fonarow said. "These kinds of quality-improvement programs can lead physicians, emergency room attendants and paramedics to close the gap and eventually eliminate sex-related differences."

Some basic biological differences between the sexes might be partially responsible for the discrepancy in survival, said Dr. Laura Wexler, senior associate dean at the University of Cincinnati College of Medicine, and another author of the report.

"For women ages 50 to 60, I wonder whether the biology of a heart attack may be different," she said. "The question is whether menopause enhances the severity of heart attacks."

The incidence of heart attack in such perimenopausal women is lower, Wexler said, "but when they do get it, the mortality rate is higher."

Still, Wexler said, "I think there are impediments to the diagnosis of coronary disease in women, including, but not exclusively, some lack of appreciation in some sectors of the importance of coronary disease in women."

More information

For descriptions about the various kinds of heart attacks and what should be done about them, visit the American Heart Association.