WEDNESDAY, Aug. 25 (HealthDay News) -- By probing deeper into the biological mechanisms that go awry in melanoma, scientists have come up with an experimental drug that has had an effect in a surprising number of patients with advanced melanoma.

The drug, PLX4032, just completed a phase 1 clinical trial in which 81 percent of participants with a particular gene mutation had a partial response, meaning at least some shrinkage of the tumor.

The current standard treatments for metastatic melanoma -- chemotherapy and interleukin-2 (IL2) -- only have response rates in about 15 percent of these patients, said Dr. Paul Chapman, senior author of a study in which the findings are described.

The average survival time for someone diagnosed with melanoma is nine to 11 months, added Chapman, who is an attending physician in the Melanoma Sarcoma Service at Memorial Sloan-Kettering Cancer Center in New York City.

One expert cautioned that it's too early to say whether the drug will actually prolong patient's lives, or if it might be helpful to patients in earlier stages of the disease.

"I don't want to say this is going to change survival rates but they're working with the most ill people, so you can't really generalize [to other patient populations]," said Dr. Alice Pentland, chair of dermatology at the University of Rochester Medical Center. "I think the most important part of this breakthrough is the bigger percentage of people who responded."

The study, which is published in the Aug. 26 issue of the New England Journal of Medicine, was funded by drug makers Plexxikon and Roche Pharmaceuticals.

About nine years ago, scientists discovered that the tumors of about half of patients with melanoma have a mutation in a gene called BRAF.

The gene appears to help drive the runaway cell division that is a hallmark of cancer. "It's always on. It's always signaling to the nucleus [of the tumor cells] that it's time to divide," Chapman explained.

That finding opened the door to potential targeted, molecular therapies for melanoma, which has been sorely lacking in effective treatments.

PLX4032 is the first potent inhibitor of BRAF that has made it to the clinical trial stage, Chapman said.

In the trial, 55 patients received escalating doses of the drug. Ten of 16 patients who had the BRAF gene mutation had a partial response to the drug, meaning the tumor shrank by at least 30 percent, while one had a complete response, with the tumor disappearing altogether.

Among 32 patients with BRAF-mutated melanoma in the second phase of the study, 24 had a partial response and two had a complete response.

"It worked: 81 percent had a partial response -- which has never been seen. I don't know of any solid tumors that have a response rate that high," said Chapman. "What's different here is that we've discovered a molecule that is responsible for driving the melanoma cell. It turns out that the melanoma really cares if we block the gene BRAF. It matters. It's addicted to this pathway."

There are some important caveats, however. It's not known at this time if the drug can improve overall survival, and a sizable proportion of participants developed resistance to the drug, the researchers say.

The findings join other recent reports of potential treatments for melanoma in what appears to be an exciting time for the field. Progress in this field has essentially been stalled for decades, experts say.

Recently, scientists reported that another experimental drug, ipilimumab, prolonged median survival in patients with metastatic melanoma from 6.4 months to 10 months.

"[Existing therapy] is not good for melanoma, so this is really a new opportunity that I think may have some importance to people," Pentland said.

However, she stressed that the best defense against melanoma is to get your skin examined regularly by a professional who knows what to look for.

"Our most successful treatment is to get [the lesion] early, get it before it's thick, get it before it spreads," she said.

More information

There's more on metastatic melanoma at the U.S. National Cancer Institute.

FRIDAY, Aug. 27 (HealthDay News) -- Nutritional supplements are popular among Americans but people need to educate themselves and use caution when using these products to try to reduce their risk of cancer, says a University of Texas expert.

"Researchers are still unsure about whether or not minerals, herbs and other plants taken in pill, capsule, tablet or liquid form actually prevent cancer," Sally Scroggs, health education manager at the Cancer Prevention Center at the University of Texas M.D. Anderson Medical Center, said in a news release from the center.

Vitamins E and C, for example, were found not to prevent cancer in the large-scale Women's Health Study and the Physicians' Health Study II. Findings from other studies suggest that some supplements may actually increase cancer risk by affecting the balance of nutrients in the body.

"If you eat lots of vegetables, fruits, whole grains and beans, you should get the nutrients, including fiber, vitamins and minerals, your body needs to lower your chances of getting diseases like cancer," Scroggs said. "Taking a pill can't replace a healthy diet."

She suggested eating plenty of foods loaded with cancer-fighting nutrients such as beta-carotene, selenium, lycopene, resveratrol and vitamins A, C and E.

While Scroggs does advise caution, there are some situations where taking supplements may benefit people, especially those who aren't getting enough nutrients due to food allergies, genetics or chronic illnesses, she said.

This includes women who are pregnant or breast-feeding; people at risk for vitamin D deficiency or osteoporosis; and people at risk for B-12 deficiency, including those aged 50 and older and vegans who consume no animal products.

Scroggs concluded that if you're considering taking supplements, consult with a doctor or registered dietician first.

More information

The U.S. Food and Drug Administration has more about dietary supplements.

MONDAY, Aug. 23 (HealthDay News) -- While the number of actual cases is still extremely small, U.S. researchers report that the incidence of rectal cancer among people under the age of 40 is on the rise.

A young person's chance of developing the disease remains tiny, but doctors should be aware of the risk, said study co-author Dr. David L. Sherr, an assistant professor of radiation oncology at Weill Cornell Medical College in New York City.

"If patients under 40 have rectal bleeding, that should be taken as seriously as in a 50-year-old," Sherr said. "Some kind of investigation could be warranted."

While colon and rectal (or colorectal) cancers often strike older people and are responsible for the second-highest number of cancer deaths in the United States after lung cancer, these cancers are fairly rare in younger people, the study authors noted in the report published online Aug. 23 and in the Sept. 15 print issue of Cancer.

Sherr estimated that only 300 annual cases of rectal cancer, on average, were diagnosed in people under the age of 40 in the entire country between 1973 and 2005. He said the risk of a person younger than age 40 being diagnosed with the disease during that time period was about four in a million.

However, an analysis of U.S. statistics shows that rectal cancer has been increasing by an average of 2.5 percent a year. While that amounts to fewer than 10 extra cases each year compared to the previous year, it's still a "real and significant increase," he said.

It's not clear why cases are on the rise, but Dr. Jerald D. Wishner, a cancer specialist, said he's seeing more colorectal cancer cases among young people than a decade or two ago.

"At any given time, I'm taking care of two to three patients in their 20s and 30s with colon and rectal cancer," said Wishner, co-director of minimally invasive and robotic surgery at Northern Westchester Hospital in Mount Kisco, N.Y.

Sherr, the study co-author, said sexual practices don't appear to be a likely culprit. Rectal cancer is not related to anal cancer, which is often spread through a virus when people have sex.

It's possible that rising rates of obesity could play a role because heavier weights are linked to the disease. However, he said, rates aren't up among people over 40 years of age.

What do the experts recommend? Sherr said doctors need to be aware of the possible risk that younger patients will develop the disease.

"When a patient under 40 comes in with rectal bleeding," he said, "they will almost reflexively say to the patient, 'You're too young for rectal cancer. It's hemorrhoids or something else.'"

Wishner cautioned that "we don't want people panicking as soon as they see a spot of blood on the toilet paper."

However, "when an older patient has a sign or a symptom, they're attuned to this. A 35-year-old blows it off. Cancer and things like that are not on the radar."

More information

For more about colon and rectal cancer, visit the U.S. National Cancer Institute.

TUESDAY, July 27 (HealthDay News) -- Taking advantage of recent discoveries of more genetic variants that raise the risk for breast cancer, European scientists have analyzed those variants in relation to breast cancer and found that the risk is greater with certain variants and for certain tumor types.

In the short term, the findings are expected to be of the most use to scientists in their effort to understand the biology of the disease.

"Our findings suggest that, at present, this type of polygenic risk score is unlikely to be a useful tool for population-based screening programs, but may be relevant for understanding biological mechanisms," said Dr. Gillian Reeves, a staff scientist at the Cancer Epidemiology Unit at the University of Oxford. She led the study, which is published in the July 28 issue of the Journal of the American Medical Association.

The study looked at more than 10,000 women with breast cancer, who were on average 58 years old when diagnosed, and more than 10,000 without breast cancer. All provided blood samples for genotyping in the years 2005 through 2008.

Reeves and her colleagues looked at 14 different alterations known as single-nucleotide polymorphisms (SNPs), small genetic changes within a person's DNA sequence that are associated with disease, and then tried to create a polygenic risk score.

They found the risk of breast cancer greatest for two SNPs and greater for estrogen receptor-positive forms of breast cancer than for ER-negative disease. In ER-positive tumors, estrogen fuels the tumor's growth.

"When the effects of the seven SNPs most strongly related to overall breast cancer risk were combined using a polygenic risk score, the cumulative risk of breast cancer to age 70 among women in the top fifth for such a score was twice that among women in the bottom fifth, 8.8 percent versus 4.4 percent," Reeves said. But the risk was greater for ER-positive disease than for ER-negative disease, the researchers found.

Reeves did not find that there were any interactions between the effects of the genes she researched and other, established risks for breast cancer.

The new study drew praise from another expert, Dr. Douglas Easton, a professor of genetic epidemiology and director of cancer research at the U.K. Genetic Epidemiology Unit, Strangeways Research Laboratory in Cambridge, U.K. "It's a nice study which takes the genetic markers which we and others have identified and estimates their effects in a prospective study."

The findings that some of the SNPs are more strongly associated with ER-positive breast cancer reflect his own findings. Overall, he said, the predictive values of the SNPs is relatively weak.

Since the Reeves study, Easton said, his team has identified seven additional SNPs that appear to be linked to breast cancer risk.

"There are now about 20 known susceptibility SNPs," he said. "As further SNPs are identified, the predictive value of these markers will clearly improve."

Soon, he said, SNPs for predicting ER-negative disease more strongly may also be discovered.

More information

To learn more about estrogen receptor-negative cancers, visit the U.S. National Cancer Institute.