Science has come a long way in treating cancer, but cancer is a word that still causes anxiety for most who receive (or have loved ones who receive) the diagnosis. That anxiety is complicated by several unknowns – starting with understanding what cancer is (in user-friendly terms). Cancer (specifically, breast cancer) is the number one cause of lymphedema in the United States & so finds its way on our blog. This series will address cancer, what it is, how it may be developed, treatments & other related topics.
So, what exactly is cancer? The simple answer is cells multiplying (i.e. dividing themselves) out of control. For a deeper insight, let’s take a look at what happens on a biological level.
Our bodies are made up of cells, many different types of cells which have different functions. For example, there are muscle cells, bone cells, blood cells, skin cells, defense cells, etc. Some cells continue to multiply throughout their life (like blood & skin cells) while others stop multiplying when their type is complete (cells in our nervous system). Normal cells only multiply when they are told to do so by
- growth factors (usually a protein or hormone) &
- cytokines (“messenger” proteins)
When a cell is told to multiply, it begins a multi-step process which has “checkpoints.” These checkpoints inspect the cell, ensure it is progressing normally & allow it to continue its development. If a cell is found defective (i.e. several genes have changed or mutated), it will usually self-destruct or it will be removed by other cells (thanks to our immune system). This process is programmed so there is a balance between the cells that multiply & those that die. In cancer, however, this process is defective. Instead of self-destructing or being removed, the defective cell passes through the checkpoints & multiplies at-will. Amazingly & thankfully, this breakdown doesn’t happen very often.
Kumar, V., Abbas, A., Aster, J. (2013). Robbins Basic Pathology (9th ed.), location 1644ff. Pennsylvania: Elsevier Saunders.
Coleman, Norman, MD (2006). Understanding Cancer, p. 28ff. Baltimore: The John Hopkins University Press.
Smith-Gabai, Helene (2011). Occupational Therapy in Acute Care, p. 410. Maryland: The American Occupational Therapy Association, Inc.