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Big C or little c?

By: Daniel Williams
Photography by: Peter Collie and Lisa Saad

Do you ever want to sit opposite a doctor and be told, “You have cancer”? Me neither. I’d rather the proverbial elephant-on-the-chest or feel a strange numbness in my face than have to process those words. And like you, probably, I’m ready to make sacrifices to lower my chances of incubating a growth that slowly sucks the life out of me.

The challenge is working out which sacrifices are worth making. Over the years, researchers and worrywarts have linked such a bewildering range of agents – foods, cosmetics, appliances, even storage methods – with the Big C that you’re entitled to wonder whether damn near everything causes cancer.

Well, here’s the first piece of good news: damn near everything doesn’t cause cancer. In fact, very few things have the power to set the cancer train in motion by interfering with your DNA and triggering the chaotic cell division that leads to a life-threatening tumour.
And here’s good news item No.2: by getting just three things right, you can cut your odds of receiving the dreaded diagnosis by up to 40 per cent. Here’s the drill:

Don’t smoke.
Maintain a healthy weight.
Avoid sunburn.

Yep, smoking, obesity and sun worshipping are cancer’s most-decorated generals. “They’re so big and have such a proven association with cancer that they make all the rest pale into insignificance,” explains Professor Ian Olver.

About another 30 per cent of cancers are traceable to a combination of inherited gene defects, infectious agents (hepatitis B and C, the human papillomavirus, HIV) and chemotherapy, which causes massive cell death while compromising immunity. And toss age into the mix. Even though your body does an A-plus job at DNA replication millions of times a day, chances are, eventually, it’s going to trip up. “The single greatest risk factor for getting cancer is having birthdays,” says Professor David Currow.


THE CANCER KINGS

Professor Ian Olver Appointed CEO of Cancer Council Australia in 2006 on the back of a quarter-century’s work as a medical oncologist and researcher.
Professor David Currow Past-president of the Clinical Oncological Society of Australia; current chief cancer officer and CEO of the Cancer Institute NSW.
Professor John Zalcberg Chief medical officer and executive director, cancer medicine at the Peter MacCallum Cancer Centre, Melbourne.
Professor Bernard Stewart Internationally recognised expert on the environmental causes of cancer; head of Cancer Control within NSW Health.

“Am I going to get cancer from eating one charred sausage? No, I’m not” - Professor Ian Olver

THE SEARCH FOR ANSWERS
That leaves 30 per cent of cancers unaccounted for. And here’s the expert word on what causes those: “We have no idea,” says Professor Bernard Stewart.

You can pick up a brochure from your GP on how to prevent skin and lung cancer. But brain cancer? “We know enough to write textbooks, but we don’t know enough to issue a simple public-health message that says, ‘Do this and you’ll avoid brain cancer’,” says Stewart. The same goes for pancreatic and thyroid cancer, bone tumours, childhood leukaemia and a stack of other nasties. “It’s daunting,” adds Stewart, “that after all these years, we still have to use expressions like ‘spontaneous disease’.”

It’s no wonder, given that black hole in our understanding, that we’re inclined to seize on theories about what might cause any of the 200-odd diseases crammed under cancer’s grim umbrella.

Whenever researchers point the finger at a new villain, think of that as the start of the story, not the end. Maybe the agent in question is carcinogenic – but to rats or humans? And how carcinogenic is it? Would a few exposures be enough to set cancer off and running, or would you need to bathe in the stuff for 10 years to get an effect?

In other words, is this agent something you need to avoid? Or would it make as much sense to worry about being struck by lightning on the golf course or dismembered by a white pointer while snorkelling?

To cut through the fog on what causes cancer, we grilled four of Australia’s top experts. Don’t dryly analyse the data, we told them – tell us what you do in your lives to defuse the threat.

To maximise your chances of living until you’re 90, and to offload unnecessary anxiety, you may want to follow their lead.


CHARRED MEAT

The scenario You’re at a barbie and your host plonks down a plate of grossly overcooked sausages. “Hope you like ’em well-done,” he chortles.

The case for concern Substances called heterocyclic amines loiter in foods cooked to the point of blackening. These have been shown to be carcinogenic in animal studies. In addition, a 2009 University of Minnesota study found a slightly increased risk of pancreatic cancer in people with a preference for overcooked meat.

The expert buzz Olver and Zalcberg reckon those snags are going to taste dreadful, so they’ll stick to the salads, thanks. “But am I going to get cancer from eating one charred sausage?” says Olver. “No, I’m not.” Based on the evidence, says Stewart, there’s more reason to be wary of salami (see “Processed meats”) than overcooked red meat, but surreptitiously scraping off the charcoal before digging in would be a reasonable way to proceed.

Verdict Jury’s out.
Your defence strategy Avoid if you can.


SECOND-HAND TOBACCO SMOKE

The scenario Your old workmates light up in the beer garden at your thrice-yearly catch-up and you’re copping their fumes.

The case for concern That plume of smoke encircling you contains about 4000 chemicals, more than 60 of which are proven carcinogens, according to the US National Toxicology Program. With car exhaust and other pollutants, second-hand smoke causes around three per cent of all lung cancer cases in Australia, experts estimate.

The expert buzz Not a ghost of a doubt on our panel that second-hand smoke puts people in cancer wards. Less clear is what level of exposure puts you in danger. If you’re inhaling the stuff every day while collecting glasses in a pub beer garden, for example, you’re definitely at heightened risk. Otherwise, the consensus is that while your body can probably withstand occasional exposures, the prudent bloke would take reasonable steps to avoid even these. “I would walk away from that conversation,” says Currow.

The verdict Guilty as sin.

Your defence strategy Get yourself upwind or out of there.

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