Question: how many types of cancer exist

Peter Nguhiu answered on 10 Jul 2017:

Quite a number, actually. Cancer is not a singular, specific disease but a group of variable tissue responses that result in uncontrolled cell growth. The cells (building blocks) in your body are many and of different types. They are organised together into tissues which perform specific functions, like the way scouts in a troop have different names but are organised to do a function like clean up or hoist the flag. When cells get old they die and are replaced by their sons and daughters who, if well trained, will do similar tasks well.
Cell growth is regulated internally (based on the cell’s DNA), but also influenced by external factors (like stress – in the physics sense, hormones, chemokines and other numerous things). It’s a complex process that is quite well (but not fully) understood.
When some of those factors change, cells change in quantity (more scouts are added when the task is heavy) or in quality (scouts become better at making knots and faster at hoisting the flag when it’s freezing cold…)
When these changes run out of control (a scout refuses to follow orders), and the body is unable to control them (kick out the scout, strokes of the cane to restore order) we call this cancer.
So you can see there could be as many cancers as there are cells.
There’s a lot we don’t know about cancer though. But what we know is that prevention involves healthy living (no smoking, less alcohol, more healthy foods, more exercise), and regular screening / early detection can contribute to better health outcomes. You have a role to play in reducing cancer incidence in Kenya!