Part III
Chapter 1
How to Cope with the Side Effects
Three Types of Side Effects
In general, side effects from chemotherapy and radiotherapy can be divided into three types. The first is a set of physiological responses, which are acute and the least concerning, including appetite loss, nausea and vomiting, weakness and fatigue, as well as flu-like symptoms; all of these can be managed by specific actions.
Fig. 3.1 Common cell types in a cell renewal system
The second type of side effects is more severe and may damage cells in renewal tissues. There are a number of such cell renewal tissues in the body encompassing the hematopoietic system, the gastrointestinal tract, skin, hair, gonads, and cornea. Fig. 3.1 shows the common cell types in a cell types in a cell renewal system. The first and basic cell type is the stem cell – destroy all of these and the tissue gradually disappears. These cells are especially sensitive to both radiation and chemotherapeutic agents, and more so when they are proliferating. If over 99.9% of the stem cells are destroyed, the renewal tissue can’t recover by itself and the host will die. If stem cells are not totally destroyed, stem cell transplant and some protective agents can ameliorate some of the damage. The “committed” stem cells and differentiating cells (which may require proliferation) are also sensitive to chemotherapy and radiotherapy since they are proliferating just like the cancer cells. Finally, the differentiated cells such as platelets and red blood cells are resistant to chemotherapy. However, since the differentiated cells have a specific half-life, they are “used up” and may not be replaced as the stem cells and differentiating precursor cells have been destroyed.
The third type of side effects is
direct damage to cells in major organs such as liver, heart, and brain. These
are non-proliferating cells, and like the differentiated cells discussed above
and relatively insensitive. However, some drugs do have selective toxicity to
specific organs such as anthracyclines and cardiac toxicity.
© Jiajiu Shaw, 2021