News

Could a simple saliva test be used to detect breast cancer?

A study being released today brings just such a test one step closer to reality.

Researchers at the University of Texas Health Science Center in Houston report that they have identified abnormal proteins in secretions from the salivary glands of women with breast cancer.

For their study, the researchers recruited 30 volunteers: 10 cancer-free women, 10 with benign breast tumours and 10 diagnosed with a potentially deadly form of breast cancer.

They found 49 saliva proteins that were distinctively different in the women with tumours, compared with the healthy subjects. What's more, with additional analysis, the researchers were able to chemically distinguish between benign and malignant tumours, said lead researcher Charles Streckfus, a professor of diagnostic sciences in the dental branch of the university.

He added that the extra analysis could help eliminate "false positive results" and allow doctors to determine the patient's next treatment options immediately.

"Collection of saliva is a non-invasive procedure that can be conducted in any environment requiring no special ... equipment," the researchers write in the journal Cancer Investigation.

They envision a day when the cancer test is routinely performed in the offices of dentists or other health-care professionals.

"Why not the dentist?" asked Dr. Streckfus in a statement released with the study. "Most folks ... visit the dental office way more often than they ever see the physician." Still, the researchers concede a lot more work is needed to confirm the reliability of the test.

More reason to worry

A study released this week will undoubtedly give anxious people more reason to fret. The new research shows that chronic anxiety can significantly raise the risk of a heart attack.

Medical experts have long known that certain personality traits can influence health in a negative way. So-called Type A overachievers, impatient and hostile individuals, as well as people suffering from depression all face an elevated chance of cardiovascular disease. The new study puts nervous Nellies in this high-risk group.

So how could such diverse personality types be prone to the same medical problems? "All these personalities seem to show similar physiological reactions such as raising blood pressure, increasing heart rates ... and higher productions of stress hormones," said lead researcher Biing-Jiun Shen of the University of Southern California, Los Angeles.

For the study, the researchers conducted psychological tests on 735 generally healthy men. They were ranked according to their level of anxiety, which can encompass excessive doubts, social introversion, various phobias and extreme tension in stressful situations.

After a follow-up period averaging 12 years, the results revealed that men with the highest levels of anxiety had a 30 to 40 per cent greater chance of suffering a heart attack, compared with the most laid-back members of the study group.

But the good news is that severe anxiety can be medically treated, Dr. Shen said. "A logical next step in research [is] to see if treating and lowering anxiety for these individuals would reduce the risk of heart disease," he said in an e-mail interview. The study was published in the Journal of the American College of Cardiology.

Living a longer life

You've probably heard these four popular prescriptions for good health many times before: Don't smoke, exercise regularly, drink alcohol in moderation, and eat five serving of fruits and vegetables a day.

But how much longer would you live if you actually did all these things? An average of 14 years, according to a study by researchers at the University of Cambridge and the Medical Research Council in Britain.

To reach this conclusion, the researchers got 20,000 men and women, ages 45 to 79, to fill out questionnaires about their adherence to these four healthy habits. At the start of the study, in the mid-1990s, all the participants were deemed to be in good health. The subjects were tracked until 2006 - and researchers then did their calculations based on who was still alive. The findings, published in the journal PLoS Medicine, showed a substantial difference in mortality - averaging 14 years - between those who adopted all four healthy lifestyle practices, and those who shunned them.

"Many people are often discouraged from making changes to their lifestyle as they think they need to make huge changes, which are not feasible," lead researcher Kay-Tee Khaw said in an e-mail interview. But, she added, "even small, achievable differences in lifestyle can have a big difference in health."

Online health sense

Just about everyone now turns to the Internet for health information - whether it's about a minor ache or a major medical condition.

To aid consumers in their quest for reliable information, Toronto's Women's College Hospital has produced an online resource called Women Wading Through the Web: A Health Toolkit. The "toolkit," which provides pointers for evaluating medical research, is in PDF format and can be read online or printed out as a booklet. You can find it at womenshealthmatters.ca/toolkit.

ptaylor@globeandmail.com