Every year more than one million new cases of cancer are diagnosed. This deadly disease is only eclipsed by heart disease as the number-one killer. By 2010, cancer is expected to assume the top spot as the leading killer in the United States. February marks National Cancer Prevention Month. While the cause of almost 80 percent of cancer is unknown, prevention is essential in warding off the big "C." There are plenty of measures you can take to reduce your risk. First and foremost, quit smoking. Smoking contributes to lung cancer, as well as other cancers. Always use sunscreen. Every year an estimated 1 million Americans are diagnosed with skin cancer. Protection is at your fingertips, and it's as simple as slathering on the sunblock whenever you go outside. Following a well-balanced diet chock full of fruits and vegetables is also advantageous. Fresh produce contains antioxidants which repair damaged cells that cause cancer.