by: Ben Kim
July 29, 2012
Over the years, I’ve found that many people don’t seem to realize that the vast majority of malignancies aren’t palpable and don’t create symptoms for several years, and sometimes decades. This is a critical point to understand, as our choices today are unmistakeably what determine our risk for cancer and most chronic diseases in the years ahead – even thirty, forty, fifty years ahead.
When looking to understand the pace at which cancer grows and spreads, the main concept to consider is doubling time, which is the amount of time it takes for one cell to divide or for a group of cells (like a benign or malignant tumor) to double in size.
Doubling time is different for various tumours, but if you know the size of a tumor at two different points in its lifespan, you can calculate doubling time with the following online resource: Doubling Time.
To put this idea into numbers that are easily visualized, let’s say that a 1 millimeter mass (about one-fifth the diameter of a dime) is detected within lung tissue on a CT scan. If this same mass is measured to be 15 millimeters (the diameter of a dime) two years later, doubling time for this mass is 105 days.
Here’s the take-home point: a 1 millimeter cluster of cancerous cells typically contains somewhere in the ball park of a million cells, and on average, takes about six years to get to this size. Generally, a tumor can’t be detected until it reaches the 1 millimeter mark.
So to develop a mass that is likely to be problematic (say, about 5 centimeters to put a number to this example), make no mistake in understanding that this is a journey of many years.
To put it another way, a person doesn’t go from being relatively healthy to having cancer suddenly appear and spread throughout his body within a few months or even a year. To have a growth that is visible to the eye or cancer that has metastasized, generally, it’s scientifically sound to state that the cancerous mass began developing many years ago.