TUESDAY, May 27 (HealthDay News) -- A common genetic variant increases the risk of lung cancer, even in nonsmokers, researchers report.

The findings -- that certain forms of the alpha1-antitrypsin gene double someones risk of developing lung cancer, regardless of whether he or she ever smoked -- could help explain why some nonsmokers develop the disease, said study author Dr. Ping Yang, of the Mayo Clinic.

The study also sheds light on why some smokers never develop lung cancer while others do, added William Phelps, scientific program director at the American Cancer Society.

"Part of the reason may be changes like this that are fairly common in the population," he said. "It is a common mutation that adds a modest amount of risk."

Alpha1-antitrypsin (AT) gene deficiencies are among the most common genetic disorders in the United States, affecting at least 10 million Americans. An estimated 11 percent to 12 percent of lung cancer patients in the study carried the defective gene variants, said the study authors, who published their findings in the May 26 issue of Archives of Internal Medicine.

According to Yang, the link between AT deficiency (ATD) and lung cancer involves another disease called chronic obstructive pulmonary disease (COPD). People with COPD are at greater risk of lung cancer, and the diseases often coexist in families, suggesting a genetic link. People with two abnormal copies of the AT gene develop early onset emphysema and ultimately COPD. But those with just one bad copy often have no symptoms at all, the study authors said.

"These carriers may be more vulnerable to carcinogen-containing tobacco smoke than non-carriers in developing lung cancer, especially when their alpha1-AT levels are compromised under physiological stress or have sub-clinical lung tissue damage," Yang explained.

For the study, Yang and her colleagues recruited 1,856 lung cancer patients and two control groups -- 902 unaffected siblings and 1,585 age-, gender-, and ethnicity-matched "community residents." Then they collected blood samples, determined the alpha1-AT status, and used statistical analyses to tease apart the effects of each variable.

The researchers saw a 70 percent increased risk of developing lung cancer among alpha1-ATD carriers, regardless of smoking history. The number increased to 100 percent for the unrelated control group -- that is, the risk of developing lung cancer doubled for those who are alpha1-ATD carriers. COPD was an independent risk factor, accounting for about a three-to-five-fold increase in risk on its own.

"Our results demonstrated that the alpha1-ATD allele can double an individual's lung cancer risk regardless of smoking history, and also confirmed that COPD is an independent risk factor for lung cancer," Yang said.

Phelps said the findings add up on a molecular level.

"It mechanistically makes sense to me in that a subtle deficiency in this gene could increase damage to the lungs. And in many types of cancer, when you see chronic damage and inflammation, that can lead to cancer," he said.

Just as the chronic liver damage that results from hepatitis viruses leads to inflammation, tissue damage, and sometimes cancer, so too might a lack of alpha1-AT lead to lung cancer, he said.

"The most interesting thing is there are a fair number of people in the population who have this mutation and don't know it, because it won't be clinically obvious. And yet it appears to double their risk of lung cancer based on this study," Phelps said.

Yang said that, although ATD appears to correlate with a high risk of lung cancer, the time is not yet right for genetic testing. Instead, she suggested that a multi-gene diagnostic test, evaluating alpha1-AT in the context of other lung cancer-related genes, might be "more sensitive and specific in predicting lung cancer risk."

"Smoking remains the overwhelming risk factor for lung cancer development," she said. "Although this study helps explain why people who have never smoked can develop lung cancer, it does not represent a pass for smokers. It doesn't mean that people who don't have the gene won't develop lung cancer."

More information

To learn more about lung cancer, visit the U.S. National Library of Medicine.

TUESDAY, May 27 (HealthDay News) -- A new review of existing research suggests that cancer patients undergoing radiation or chemotherapy avoid supplements with high levels of antioxidants.

Although multivitamins may be all right in some cases, even green tea and vitamin A or E supplements can spell trouble, said review author Dr. Brian Lawenda, clinical director of radiation oncology at Naval Medical Center in San Diego.

The supplements "may decrease the effectiveness of radiation or chemotherapy or even make the toxicities of these treatments worse," Lawenda said. "I would recommend that you do not take these agents during chemo or radiation."

According to Lawenda, many cancer patients take supplements and green tea because they think antioxidants will help their treatment. Antioxidants are generally considered healthy because they help protect cells against threats in the body.

"Everybody wants to take them," said Dr. Alfred Neugut, the head of cancer prevention and control for the Herbert Irving Comprehensive Cancer Center at Columbia University in New York City. "It comes up almost every day in almost anyone's practice."

But researchers have questioned the conventional wisdom, wondering whether antioxidants might actually harm cancer patients during treatment.

In the new review, reported in the May 27 online edition of the Journal of the National Cancer Institute, Lawenda and colleagues examined studies into antioxidants and cancer therapy.

The researchers found that only three studies on radiation and antioxidants relied on randomized controlled trials, which are considered the best way to compare medical treatments.

One of the studies found that antioxidant treatment appeared to raise the likelihood of death.

The antioxidants may protect cancer cells from harm just like they protect normal cells, Lawenda said, and therefore prevent cancer treatments from killing tumors.

The researchers did find 16 randomized controlled trials that looked at antioxidants and chemotherapy, but they said the findings weren't conclusive.

"The quality of these studies, in terms of many of the details, is not sufficient enough for us to make strong recommendations to our patients on the safety of using these agents during radiation or chemotherapy," Lawenda said.

Overall, however, the effect on life spans of taking antioxidants appears to be small, he added.

Lawenda said he tells his patients they can take a daily multivitamin, but he recommends they avoid high-dose supplements.

Still, "we don't know whether even a multivitamin is OK to take," he added. "We don't know if even the USDA levels are acceptable. We just don't know the answers to so many questions, unfortunately."

Neugut said the findings would change what he tells patients about antioxidant supplements.

"Since there's been little evidence on the subject, I've tended to be laissez-faire about it, figuring it probably couldn't hurt," he said. "This article suggests that it seems a little bit more likely that it's more harmful than helpful."

More information

Learn more about vitamins from the National Institutes of Health.

TUESDAY, May 27 (HealthDay News) -- Adding paclitaxel to standard chemotherapy improved disease-free survival in women with early-stage breast cancer, a Spanish study finds.

The phase III trial included 1,246 women with early, non-metastatic breast cancer who were randomly assigned to receive treatment with fluorouracil, epirubicin, and cyclophosphamide (FEC), or FEC followed by weekly paclitaxel (FEC-P).

The estimated five-year survival rate in the FEC-P group was 78.5 percent, compared to 72.1 percent in the FEC group. The study also found a trend toward improved overall survival, but it didn't reach statistical significance.

"Because distant relapse-free survival is usually associated with overall survival, a statistically significant benefit in overall survival may become evident with a more protracted follow-up," wrote Dr. Miguel Martin, of the Spanish Breast Cancer Research Group.

In a retrospective analysis of the data, the researchers weren't able to identify a subgroup of patients who were more likely to respond to paclitaxel therapy on the basis of their tumor's expression of the estrogen receptor and HER2.

The study was published in the May 27 online issue of the Journal of the National Cancer Institute.

In an accompanying editorial, researchers at Memorial Sloan-Kettering Cancer Center in New York City reviewed several trials that examined the effects of adding taxanes (a family of drugs that include paclitaxel) to existing adjuvant therapy for breast cancer.

In that regard, the study by the Spanish team is important, because it was well-designed and used a good regimen and schedule of drugs, noted Dr. Clifford Hudis and Dr. Chau Dang.

More information

The National Cancer Institute has more about breast cancer treatment.

FRIDAY, May 2 (HealthDay News) -- Prompt treatment of a common stomach infection reverses the damage that can lead to gastric cancer, according to tests on mice done by researchers at the Massachusetts Institute of Technology (MIT).

The findings should put a stop to any questions about whether, and when, antibiotic treatment of Helicobacter pylori can reduce or eliminate the risk of developing stomach cancer.

"We concluded that H. pylori eradication prevented gastric cancer to the greatest extent when antibiotics were given at an early point of infection, but that eradication therapy given at a later point also delayed the development of severe lesions that can lead to cancer," study author James G. Fox, director of the division of comparative medicine at MIT, said in a prepared statement.

Stomach cancer is the second-leading cause of cancer death worldwide and about half the world's population is infected with H. pylori, which is recognized as a major cause of both peptic ulcers and stomach cancer. It typically takes several decades for stomach cancer to develop in people who are susceptible -- about 3 percent of people infected with H. pylori.

It's been unclear when doctors should screen and treat people with antibiotics -- other than immediate relatives of patients with stomach cancer and peptic ulcer disease -- or when to treat H. pylori infection for maximum benefit, Fox said.

He and his colleagues created mice prone to accelerated H. pylori infection and progression to stomach cancer. The researchers found that mice treated with antibiotics had less severe disease at every stage of advancing infection.

Mice treated eight weeks post-infection had the same risk of cancer as uninfected mice. However, treatment at 12 and 22 weeks post-infection didn't reverse damaging changes, such as inflammation and development of precancerous lesions, to levels seen in uninfected mice.

"Our mouse model mimics the progressive process we know occurs in the development of human gastric cancer. This [study] shows early intervention provides the maximum benefit," Fox said.

The study appears in the May 1 issue of Cancer Research.

More information

The American Cancer Society has more about stomach cancer  .