6 August 2011
This week is part II of an article inspired by Anne Kenworthy:
What does it mean to have a “normal” cancer marker? Does this mean we all walk around with some level of “cancer” in our bodies and this is the acceptable level? What’s going on?
Each of us is made up of trillions of cells. According to cell death and renewal expert Dr. John Reed of the Sanford-Burnham Medical Research Institute, every day 50-70 billion cells purposefully undergo cell suicide and are replaced by new, healthy cells. It is this equilibrium of death and renewal in our tissues that keeps us young. This process is also a key defense mechanism against cancer. When a cell begins to go on the road to becoming cancerous (see hallmarks of cancer article) the surrounding cells or immune system will usually detect this progression and send signals to tell the offending precancerous cell to die. This process is called: apoptosis. Defects in this process can lead to cancer in both experimental models and in rare genetically heritable forms of the disease (1). And, most common cancer drugs exploit this mechanism to help a patient battle the disease.
I have seen mathematical models that suggest that each of us starts to develop cancer several times a day! The regular equilibrium of death and renewal in our tissues usually keeps new cancer in check. As we get older, this turnover slows. This is one hypothesis for why cancer is an age-related disease. An unlucky roll of the dice combined with a very, very, very, rare event is required for cancer to arise. The older one is, the more often the dice are rolled. And yes, some people do get cancer at younger ages as well.
This area is somewhat murky for experimental science. It is hard to detect, or to model these events in the body. It is nearly impossible to tell if someone had a pre-cancer that spontaneously regressed, especially if said person never had any symptoms and went about a normal life without ever seeing a doctor and taking a body scan.
So, it IS actually possible that many of us walk around with some undetectable level of cancer. But, low levels of “tumor” markers are not necessarily indicative of cancer. And, it is not a good use of mental energy to worry about it nonstop, as one has about as much voluntary control over these processes as, say, the rate of digestion in your gut or your sleeping heart rate. If one is at risk of developing cancer or relapsing, regular check-ups combined with healthy dialogue with a medical doctor is a good bet to promote physical and mental wellness.