WEDNESDAY, Oct. 10 (HealthDay News) -- When added to a standard chemotherapy, the drug paclitaxel (Taxol) cuts the recurrence of breast cancer by 41 percent in women with a particular form of tumor, a new study finds.

Those tumors are called "HER2-positive" because their cells produce an excess of the protein human epidermal growth factor receptor-2 (HER2).

In recent years, cancer specialists have found that breast tumors with different characteristics respond differently to various regimens. The new study adds another piece to that puzzle, experts say.

"Over the last 10 years, we have come to realize that breast cancer isn't one disease but a family of diseases," explained study co-author Dr. Eric Winer, director of the breast oncology center at the Dana-Farber Cancer Institute in Boston. "In this study, what we saw is very different benefits for paclitaxel in different subgroups of women," he said.

"This adds to a growing body of literature" about which chemotherapy regimens benefit which types of tumors, added the study's lead author, Dr. Daniel F. Hayes, clinical director of the breast oncology program at the University of Michigan Comprehensive Cancer Center and professor of internal medicine at the University of Michigan, Ann Arbor.

"We can use the biology of the cancer to select the [appropriate] chemotherapy," he said.

The findings are published in the Oct. 11 issue of the New England Journal of Medicine

The researchers randomly selected 1,500 women from 3,121 patients with lymph node-positive breast cancer, meaning it had spread to nearby lymph nodes; all were part of the Cancer and Leukemia Group B study, a national clinical research effort sponsored by the U.S. National Cancer Institute.

The women had been randomly assigned to get the standard anti-cancer drugs doxorubicin plus cyclophosphamide, followed by either four cycles of the drug paclitaxel or observation only.

The researchers than analyzed tissue samples supplied by the women, looking for the expression of HER2 as well as the tumor's estrogen receptor status.

"Most guidelines say, if a tumor is node-positive, chemo is recommended," Hayes said.

In this study, they found that paclitaxel helped those women whose tumors are HER2-positive, regardless of whether they were estrogen-receptor positive or negative. In contrast, patients whose cancers were HER2-negative and estrogen-receptor positive did not benefit in this study from paclitaxel.

Over the follow up of about 10 years, adding paclitaxel for the treatment of HER2-positive tumors reduced the risk of recurrence by 41 percent.

About 60 percent of women with breast cancer will have HER2-negative and estrogen-receptor positive tumors, noted Winer, who is chief scientific adviser for Susan G. Komen for the Cure, a nonprofit advocacy group.

Hayes did offer one strong caveat: "We want to be cautious about this data," he said, adding that the findings need to be confirmed in other studies.

Winer cautioned that the study, "doesn't tell us what we should do when we approach the patient in clinic tomorrow. We don't want people to say no to chemo based on these results only."

In an editorial accompanying the study, Dr. Anne Moore from Weill Cornell Medical College, New York City, concluded that "the days of 'one size fits all' therapy for patients with breast cancer are coming to an end.''

More information

For more on breast cancer treatment, head to the American Cancer Society  .

TUESDAY, Oct. 9 (HealthDay News) -- Three genes that appear to work together are associated with 20 percent of lung cancers, and these same genes are linked to fetal lung development, researchers report.

Understanding how these genes mesh could be an important step in stopping tumors from forming, according to the report in this week's issue of the Proceedings of the National Academy of Sciences.

"We have discovered a frequent genetic mutation in lung cancer," said lead researcher David Mu, from the Cold Spring Harbor Laboratory in New York. "This mutation is found in 20 percent of non-small cell lung cancer, which makes up about 80 percent of all lung cancer."

For the study, Mu's team looked at lung cancer tumor tissue and found that the three genes -- designated TTF1, NKX2-8 and PAX9 -- work together to promote tumor growth. The genes are located next to each other on chromosome 14.

These genes are also involved in the normal development of lungs in the embryo, Mu said. "However, in adults, they can be mutated into a malignant form helping lung cells turn into cancer cells," he said.

This phenomenon of three genes working together to enable cancer cells appears to be unique to lung cancer, he said.

Mu noted that this finding could have important medical applications. "We are looking at identifying patients with this type of mutation to find out what prognosis they have," he said. "We are actively researching this."

It may also be possible to block these gene mutations and prevent tumor growth, Mu said. "Understanding how these genes work is important. In addition, there may be other genes that are important for the function of these genes and might be better targets for therapy," he said.

Dr. Michael Thun, head of epidemiological research at the American Cancer Society, said the discovery could lead one day to predicting lung cancer prognosis and designing individual treatment.

"There is a search on to find the gene mutations involved in cancer," he said. "If you know what genes are malfunctioning in a cancer, it is useful in predicting prognosis, and you can tailor treatment to fit the abnormalities that are present in the tumor tissue."

Thun also said that knowing the genetic components of a cancer can help determining who's at risk for developing a specific malignancy.

More information

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

TUESDAY, Oct. 9 (HealthDay News) -- Prostate cancer patients receiving androgen-deprivation therapy, a common form of hormone treatment proven to slow tumor growth and prolong life, may face a nearly threefold higher risk of dying from heart disease, a new study suggests.

The apparent danger results from a drop in testosterone levels that is central to androgen-deprivation therapy's (ADT) effectiveness at curbing prostate cancer, the study authors said.

This drop in testosterone can provoke insulin resistance, leading to type 2 diabetes, as well as a gain in body mass, body fat and so-called bad cholesterol. Collectively, this group of problems is called the "metabolic syndrome," a condition long-associated with cardiac complications.

"However, I think overall ADT does help people with prostate cancer, and until it's studied further this can't be considered proof that there's a connection between the cardiac effects and hormone therapy," said study author Dr. Henry K. Tsai, who throughout the study period served as a resident in training in the Harvard Radiation Oncology Program in Boston.

"But patients need to think about being evaluated carefully by their doctor to see whether they're appropriate candidates for hormone therapy and be informed about the potential risks," Tsai added.

This new finding, published in the Oct. 17 issue of the Journal of the National Cancer Institute, follows research released in 2005 that highlighted ADT's link to an increased risk for bone fractures and osteoporosis.

The new findings are based on an analysis of medical records and questionnaires completed by nearly 4,900 patients between the ages of 39 and 86 who had been diagnosed with localized prostate cancer between 1995 and 2004.

All the patients had participated in a larger nationwide prostate cancer research project involving more than 13,000 men, during which all had indicated whether they had any preexisting medical complications in addition to cancer.

Of the 4,900 patients, nearly 3,300 had undergone prostate removal surgery following diagnosis.

The remainder underwent nonsurgical treatments, such as external beam radiation therapy; brachytherapy (involving the insertion of small radioactive pellets directly into the prostate); and/or cryotherapy (involving the freezing of tumor cells).

In addition, 266 of those patients who underwent surgery and 749 of those receiving an alternate treatment also received androgen-deprivation therapy.

The patients were tracked for an average of about four years following the start of all treatments; the patients receiving ADT did so for an average of about four months.

Tsai and his colleagues found that patients over the age of 65 who had undergone both prostate removal surgery and ADT had a 5.5 percent increased risk of dying from a cardiac event within five years of starting the hormone treatment. This compared to a 2 percent greater risk among patients older than 65 who had surgery alone.

The "relative risk" jump was similar among younger patients. Those under 65 who had surgery and hormone therapy had a 3.6 percent greater risk of death from heart disease within five years, compared with a 1.2 percent risk among those undergoing surgery alone.

ADT was not associated with any increased cardiac risk among patients undergoing any of the nonsurgical treatments.

An editorial accompanying the study calls for more research into the topic.

Jerome Seidenfeld and his colleagues at the University of Connecticut Health Center suggest that while Tsai's analysis of previously collected data raises an "interesting hypothesis," no definitive link to cancer risk can be proved until a clinical trial of prostate cancer patients currently undergoing hormone treatment is launched.

Tsai agreed.

"I pretty much feel similarly," Tsai said. "The editorial emphasizes that this is a preliminary study, and clinical trials are the gold standard. And we need one to confirm our findings."

Tsai, currently working as a radiation oncologist with Radiation Oncology Consultants in Princeton, N.J., said he doesn't want prostate cancer patients to view androgen-deprivation therapy with alarm.

"I don't think patients should be afraid," he said. "This is just what I'd call emerging data, and while the relative increase in risk for heart disease is large, in absolute terms the risk is still very small."

Dr. Nelson Neal Stone, a clinical professor of urology and radiation oncology at Mount Sinai School of Medicine in New York City, said the exact mechanism by which ADT might boost the risk for cardiac complications remains undefined, despite a widespread appreciation for the array of problems that accompany the metabolic syndrome.

In that light, he suggested that physicians should target the onset of the life-threatening syndrome as well as the life-prolonging treatment.

"The message is that we need to start paying attention to our patients' general health when we put them on hormonal therapy," he said. "And perhaps we should be putting them on a diet to control for the potential side effects of the therapy, and the serious impact it can have on their health."

"We can't take away the hormones altogether because there's a major benefit to that treatment," Stone added. "But we need to develop a good strategy for dealing with the negative consequences that occur."

More information

To learn more about prostate cancer and its treatment, visit the American Cancer Society  .

THURSDAY, Sept. 20 (HealthDay News) -- The current chemotherapy regimens of irinotecan, oxaliplatin, and molecular-targeted treatments are helping patients with advanced colorectal cancer live several months longer than they did a few years ago, when these therapies weren't available, Greek researchers say.

Researchers at the University of Ioannina School of Medicine performed a meta-analysis of 242 studies on these chemotherapies, conducted over the past 40 years.

The study was published online Thursday in The Lancet Oncology journal.

Previous studies have noted survival benefits for patients receiving the newer regimens, but the degree of these benefits across assorted regimens has been less clear, the team said.

They conducted the meta-analysis to examine whether certain treatment regimens for advanced colorectal cancer offer better survival and delayed disease progression and to determine the extent of such benefits.

According to the study, among patients who would be expected to live for one year when treated with the drugs fluorouracil and leucovorin, there was an estimated absolute survival benefit of an extra eight months if patients received additional treatment with irinotecan plus bevacizumab.

The researchers also concluded that the addition of oxaliplatin plus bevacizumab or irinotecan plus oxaliplatin offered four to seven additional months of survival for patients.

However, the researchers also noted that multidrug combinations that improve survival can cause serious toxic side effects. They called for long-term follow-up data on toxicity associated with these treatments.

"The fluorouracil, leucovorin, irinotecan, plus bevacizumab regimen especially, which has the highest probability to be the best in improving survival according to our analysis, might be complicated by up to 84.9 percent of grade 3 or 4 adverse events, including a 1.5 percent chance of gastrointestinal perforation," the researchers noted. "(These) existing uncertainties suggest that more data are needed, especially for the newest regimens", they said.

More information

The American Cancer Society has more about colorectal cancer treatment decisions  .