Elizabeth Edwards, wife of Democratic presidential candidate John Edwards, has had many routine medical follow-ups since her 2004 breast cancer diagnosis. And all of them -- until just a few days ago -- resulted in what is generally termed a clean bill of health.

The term doesn't always come with a sense of relief for those of us surviving breast cancer -- or any cancer for that matter -- because it only really defines what our bodies are telling us at one specific moment. There are no magic blood tests, no special body scans, no conclusive ways of determining whether or not cancerous cells have gone astray and will one day surface again.

I asked my oncologist after my first six-month follow-up how he would know if my cancer returns. He told me it's really up to me to determine whether it comes back. It's up to me to get mammograms and ultrasounds and MRIs. It's up to me to report any symptoms and suspicions. It's up to me to track my general well-being so that it will be clear when something feels not-so-right. If I have a persistent cough or headaches that won't subside, my doctor will take action with X-rays and scans and tests. But as long as I feel fine and nothing troubling presents itself, then I remain in the clean-bill-of-health club.

Edwards no longer has a clean bill of health. But she is determined to use her newest diagnosis -- stage four metastatic cancer of the bones, considered treatable but not curable -- to work toward the best health she can acquire for as long as she can hold onto it. And that is about as good as any of us can do.