CANCER - How to prevent cancer

Some surprising ways you can help prevent the disease

 

The figures are startling: more than 40,000 Australians will die of cancerthis year, and one in three women will be diagnosed with the disease before their 85th birthday. But here's another statistic: about half the cases could have been prevented. A family history of the disease is obviously a risk factor, but consider that your height, the number of children you have, how many men you've slept with and how long you've been on the contraceptive pill all influence your likelihood of developing cancer.

Quit smoking

Professor Ian Olver, Cancer Council Australia chief executive, says tobacco use - despite smoking rates falling to below 17 per cent - remains the biggest lifestyle risk for developing cancer. "Because most cancers are a mix of genetic and environmental factors, it's important not to exacerbate the genetic risk by avoiding environmental risks," he says. In Australia, the main three environmental risks are tobacco, obesity and sun exposure. Smoking accounts for 90 per cent of all lung cancers, which now kill more women than breast cancer.

Physical activity

Exercise can lower women's risk of pre-menopausal breast cancer. The risk of breast cancer in a woman who goes through menopause at age 55 is 40 per cent higher than in a woman who goes through menopause at age 45 because they're exposed to 10 more years of period-related hormones.

"Obviously we have no way of influencing that. But the impact of that 10-year difference in menopause is the same magnitude risk for breast cancer as having a family history of it," says Australian cancer expert Professor Graham Colditz, now at the Washington University School of Medicine in the US.

The earlier you start menstruating, the greater the lifetime risk of developing breast cancer, again because of the longer exposure to oestrogen. But there are ways to cut your risk. Girls who are physically active from the time they get their period have a 25 per cent lower risk of pre-menopausal breast cancer.

"We're not talking about extreme sports, we're talking about recreational activity, which is enough to cut breast cancer risk by a quarter, " Professor Colditz says. "Being physically active significantly reduces the risk of developing cancer. We can get up to a 50 per cent reduction with half an hour of activity a day. And in the case of bowel cancer there appears to be even higher levels of protection with higher levels of activity."

Eat less red meat

Eating red meat every day heightens the risk of bowel cancer by five to 10 per cent, while there is a 10 to 20 per cent increased risk associated with being overweight or obese.

Reducing salt and alcohol

Professor Ray Lowenthal, a cancer specialist at the Royal Hobart Hospital and the University of Tasmania, says alcohol intake can also be an indicator of whether or not you will develop cancer.  "High alcohol intake, especially if one is also a smoker, is a risk factor for head and neck cancer and cancer of the oesophagus," he says.

Drinking three or more alcoholic beverages a day means you have a 10 to 20 per cent increased risk of developing cancer. High salt intake has been linked with stomach cancer. Leading a healthy lifestyle could reduce the risk of cancer by 30 to 50 per cent, though the figure is debatable, Professor Lowenthal says.

Staying sun safe

Australia is known for its harsh sun and has the highest rate of skin cancer in the world. The slip slop slap campaign is well known and some Sydney beaches played a Ben Lee jingle composed for the Cancer Council NSW at regular intervals last summer to remind sunbathers to reapply sunscreen. Red-haired, fair-skinned people burn easily and those with lots of moles need to be especially careful. People who have had several blistering sunburns as a child are at 15 per cent greater risk for each sunburn. And solariums are no substitute when seeking that bronzed look as they too have been found to cause cancer.

Having children

Because of changes to breast tissue associated with pregnancy and breastfeeding, children also play a significant role in whether or not you will contract cancer. American researchers say pregnancy permanently changes breast tissue, making it less likely to become cancerous, so the later this change occurs in a woman's life, the more time the breast cells have had to become abnormal and cancerous.

But women lower their risk of developing these cancers with each child they have, and breastfeeding for a total of a year or more lowers the risk of breast and ovarian cancer because hormonal changes and changes to breast tissue protect the cells. However, on the flip side, women who have two or more children have a higher risk of cervical cancer, with researchers suggesting it may be related to injury to the cervix when the baby leaves the uterus.

Screen tests

Women who have regular Pap tests are less likely to develop cervical cancer and there is now a vaccine, Gardasil, against the human papillomavirus. Those who have sex for the first time at an early age, who have lots of male partners or contract a sexually transmitted infection are all at greater risk of contracting cervical cancer, but regular testing makes this less likely.

For all cancers, the risk increases with age. That's not to say young people don't develop cancer, but more than four times as many cancers are detected in people aged over 60. Screening programs for breast, cervical and bowel cancers have improved early detection and treatment and those who get tested regularly are less likely to develop the disease.

The contraceptive pill

The risk of developing breast cancer while taking the contraceptive pill is said to be higher, but researchers have actually found that if taken for more than five years, the pill can lower a woman's risk of colon, uterine and ovarian cancers.

Genetics

According to National Health and Medical Research Council figures, five to 10 per cent of common cancers are caused by a genetic predisposition. "But even if you're genetically predisposed, you still need an environmental risk to bring out that predisposition," says Professor Stephen Clarke from the Sydney Cancer Centre.Professor Clarke says people with a predisposition should be screened earlier than others.

"It's impossible to completely avoid any risk factors, but they should definitely avoid smoking and you can now avoid viral risk factors for cancer with appropriate vaccinations. "Professor Olver says explaining to a patient why they have cancer when they have no family history of the disease and have led a healthy lifestyle can be tough. "One of the difficulties is there is no one cause [of cancer] ... it usually requires four to five changes in genes to trigger the disease, '' he says. "You might be born with two and three can be environmental. Some people just seem to be unlucky."

Professor Lowenthal says that in the end, it all comes down to statistics. "Adhering to a healthy lifestyle will reduce the risks of getting cancer, not eliminate them," he says.And that's where luck comes in - being exposed to enough risk factors to cause the cell changes to trigger cancer. Researchers are now looking at maternal health while in utero to determine whether that also has an influence on whether or not you will develop cancer. Cancer patients are living much longer than 50 years ago and a "revolution" in cancer treatment is offering fresh hope.

Personalised medicine is also now enabling cancer specialists to tailor treatments to individual patients, getting better response rates with less toxic therapy. "The first generation of these drugs is coming through and over the next 10 years we'll see a stronger emphasis on targeted cancer therapies and less emphasis on chemotherapy," Professor Olver says.

Source: http://www.bodyandsoul.com.au/