SAN FRANCISCO — When it comes to fighting cancer, the good news is that many kinds are subject to delay or avoidance by making smart lifestyle choices. Some of the behavioral tweaks recommended by a leading cancer doctor may surprise you.Of course, the formula for preventing cancer isn't iron-clad, nor is it one size fits all. That's according to Dr. David Agus, an oncologist, professor of medicine at the University of Southern California in Los Angeles and author of the new book “The End of Illness,” which examines the scientific evidence behind his conclusions.“As a cancer doctor on the front lines, one of the first things you realize is the best way to treat cancer is actually to prevent it,” he said in a recent interview.Medicine has spent too much time looking at individual cells and fixating on individual tests instead of studying whole systems and how they interact over time, Agus said, noting that diseases like cancer reflect a breakdown of the body's interconnected systems.“To me diseases are verbs, not nouns. You're cancering. You're heart diseasing,” he said. “That's a very different approach to health.”Agus is cofounder of Navigenics, a personal genomics company that contracts with doctors and employers to try to motivate people to change their behavior based on findings about their genetic predispositions. He's also cofounder of Applied Proteomics, which studies how proteins are expressed in the body. Agus holds a small financial stake in both firms.Other personalized-medicine outfits with different business models, including 23andMe and DNA Direct, have sprung up in the past six years as concern about managing health-care costs has grown. But you don't need to buy one of these companies' services to take steps toward living a longer, healthier life.Here are 10 ways to help your body prevent the ravages of disease, according to Agus:1. Keep a predictable schedule. Try to eat, sleep and exercise at about the same time every day including weekends, and don't forget to schedule downtime to unwind without technological intrusions. Getting enough shut-eye is important for memory consolidation, mood balance and long-term physical health, he says, but regularity of sleep patterns matters more than total hours slept. Having trouble adhering to a routine? Consider getting a dog, he suggests. Dog ownership involves walking and feeding it at regular intervals, forcing people to stick to the clock, get some physical activity and take breaks from working.2. Move frequently and avoid prolonged sitting. Fitness is paramount to your body's overall functioning, and you won't have to sweat the risks of pills or surgery. What's more, sitting for long stretches of time has been linked to a higher risk of early death and many diseases including colon cancer. It's easy to underestimate how long you stay seated during the day.Even Agus was surprised to learn how sedentary he was after wearing a device that measured his activity. Finding out that he had three hours of daily uninterrupted sitting motivated him to buy a wireless phone headset that allowed him to walk around during conference calls, resulting in a 35 percent greater number of steps taken per day.Agus's prescription: aim for an hour of moderate exercise a day (short bouts count, too) and keep a set of free weights nearby so you can sneak in some bicep curls. “I'd suggest you keep a pair of 2.5-pound weights by your desk, under your couch and anywhere you spend time,” Agus writes in his book. “Stand on one foot and do 20 reps while on your next phone call with a headset; this is a great abdominal exercise that also helps you work on your balance.”3. Ditch the vitamins and supplements. Unless you're addressing a confirmed vitamin deficiency, are considering pregnancy or are already pregnant, you can steer clear of multivitamins and save money without sacrificing your health, Agus says. Some people believe they need supplements to fight a battle with so-called free radicals, but the body already has defenses against such byproducts of metabolism, he says, and the effects of interfering with the body's natural control system aren't well understood. In the meantime, many studies point to no benefit and sometimes harm from vitamins and supplements. Vitamin E supplementation, for example, was found to raise the risk of prostate cancer 17 percent in healthy men, according to a study published last year in the Journal of the American Medical Association.4. Get an annual flu shot. Having the flu triggers inflammation, which can set the body up for serious problems when it's most vulnerable, he says. The flu vaccine, whose contents change every year according to the dominant viral strains projected to circulate, helps the body tone down its harsh immune response. “I want (people) to think of a flu shot in terms of not just what it means today but a decade from now,” Agus says.5. If you're over 40, talk with your doctor about the benefits and risks of taking a statin and low-dose daily aspirin if you're not taking them already, he says. These low-cost medications have been shown to reduce the risk of heart attacks, strokes and even some kinds of cancer, but they also have side effects you should weigh carefully.6. Wear comfortable shoes. Nix the high heels and other uncomfortable footwear in favor of shoes that don't cause swelling or curtail your movement, Agus says. Picking shoes that won't cause back or joint problems can help you cut your risk of chronic inflammation. “Over weeks, months, years, (wearing comfortable shoes) changes your overall health, and you're also going to move more,” he says.7. Take inventory of your medicine cabinet once a year. Go over your list of drugs with your doctor to see if your needs have changed and if you can lose at least a few of them. “Health is a constantly moving target,” Agus writes.8. Cash in on healthy-living incentives. Your employer may offer lower insurance premiums in exchange for taking a health-risk assessment or cut you a break on the cost of a gym membership. Your premium dollars might include the services of a health coach, who can help you set and stick to goals around making sustainable life-style changes. “How do we make health profitable instead of sickness?” Agus says. “Put in incentives for prevention.”9. Think of your doctor as a partner, not a friend. Ask your physician what he or she does to stay current on the latest scientific information, Agus suggests, and if you don't feel you can tell your doctor anything, find a new one.10. Know yourself by keeping records of your medical data. Perhaps Agus' most controversial tip is to store it online. But old-fashioned paper will do. If you jot down dates, symptoms and treatment trial and error, it may allow you to discover patterns that can help you and your doctor catch problems early and customize your care more effectively.