About 40 per cent of women are thought to regularly use talcum powder for personal hygiene. Traditionally used on babies' bottoms and by older women, talcum powder is used to keep skin dry and avoid rashes. But should we stop dusting the talc? Cancer Australia's chief executive Professor Helen Zorbas says: “Recent studies reflect ongoing interest in research around risk factors for cancer. However, risk for cancer often involves a complex interaction of factors and for many cancers the causes are not fully understood and knowledge is evolving.” There is established evidence about some well-recognised factors that place individuals at greater risk for cancer. “It is estimated that at least one-third of all cancer cases are preventable. Lifestyle choices people can make to reduce their risk include quitting smoking, maintaining a healthy weight, being active, eating a balanced and nutritious diet, limiting alcohol consumption and being sun smart,” Zorbas explains.

While smoking, obesity and unhealthy diets are the biggest risk factors for cancer, there are a range of other little-known factors that have also been linked to deadly cancer. Here's five of the most surprising. Fido There may be a darker reason a pet dog is a cancer patients' best friend. Analysis of breast cancer cases by researchers at the University of Munich showed that 79.7 per cent of all breast cancer patients had regular contact with dogs before diagnosis. Only 4.4 per cent of the patients did not have pets at any time, compared to 57.3 per cent of a healthy control group. According to researchers, that's a 29-fold increased risk for pet owners. Barbecues

Ruining a piece of meat isn't the only thing backyard chefs need to worry about when grilling. High heat from barbecuing causes amino acids to react with creatine to form heterocyclic amines, a cancer-causing chemical. These carcinogens are linked with a 60 per cent higher chance of developing pancreatic cancer. Fish oil The popular dietary supplement that's extolled for its health benefits may increase the risk of prostate cancer associated with omega-3 levels by up to 71 per cent. “When it comes to prostate or ovarian cancer, which the talcum powder and fish oil studies reference, science has found nothing modifiable behaviourally to reduce cancer risks. Being diagnosed with these cancers is simply bad luck. My advice is not to worry and carry on with business,” says Professor Chris Del Mar of Bond University on the Gold Coast. Oral sex

Last month actor Michael Douglas opened up to the UK's The Guardian about his past diagnosis, revealing not smoking or drinking caused his type of throat cancer – but oral sex. We might have scoffed but according to the Oral Cancer Foundation, one tract of HPV – known as HPV16 – is known to be linked to oral cancer. Air travel Frequent fliers could be racking up more than air miles. Cabin crew are up to five times more likely to contract breast cancer and three times more likely to suffer the deadliest form of skin cancer, caused by exposure to cosmic radiation. Long-haul trips which disrupt the body clock and affect hormone levels are additional risks. Professor Ian Olver, chief executive of the Cancer Council Australia says: “There are some concerns with these reports which associate common things and cancer. Such studies require further research and larger sample sizes. If you are looking for scientific answers you can visit iheard.com.au and get answers from an online expert or visit your GP.”