Side effects of cancer treatments can be acute or chronic. Acute side effects are short-term and go away once the treatment period is over, while chronic side effects are long-term and can last for months to years after treatment. Since cancer cells are characterized by their rapid growth, chemotherapy is designed to target rapidly dividing cells specifically. However, other healthy cells can rapidly divide as well and be damaged, leading to side effects. The most common healthy cells to be affected are blood cells, hair cells, and mucous cells in the mouth, throat, and digestive system.[1]

Common side effects resulting from damage to healthy blood cells include anemia, easy bruising and bleeding, and infection.1 Blood is made up of a fluid called plasma and three main cell types: red blood cells, white blood cells, and platelets.2 Red blood cells are responsible for transporting oxygen through the bloodstream, and when these cells are damaged by chemotherapy it can lead to anemia. Anemia occurs when there are not enough healthy red blood cells to carry the necessary oxygen throughout the body. White blood cells are a major part of the immune system, and when these cells are damaged by chemotherapy it increases the risk of infection. Platelets are responsible for blood clotting, and when these cells are damaged by chemotherapy it increases the risk of bruising and bleeding.[1,2]

Hair loss is a common side effect of chemotherapy that results from damage to healthy hair cells. Damage to the mucous cells in the mouth, throat, and digestive system due to chemotherapy can lead to common side effects such as nausea, vomiting, appetite changes, weight changes, mouth sores, difficulty swallowing, constipation, and diarrhea. Fatigue is another common side effect that can result from a variety of factors and be contributed to by other side effects such as anemia, nausea and vomiting, pain, and insomnia.1

Additional typical side effects include urine and bladder changes, kidney problems, skin and nail changes, nerve problems, memory problems (known as “chemo brain”), mood changes, fertility problems, and changes in libido. Most of these side effects go away soon after treatment but can become chronic.[1] Of the side effects listed, the ones that are more likely to persist for months to years after treatment are fatigue, chemo brain, nerve problems, infertility, and kidney and bladder problems. Other potential chronic side effects include hearing loss, osteoporosis (weak bones), cataracts (cloudy eyes), liver damage, and the development of secondary cancer.[3] Secondary cancer can be used to refer to an additional primary cancer or it can refer to a cancer that has spread to another location in the body. In this instance, secondary cancer refers to a second primary cancer caused by damage to healthy cells during chemotherapy.[4] Certain chronic side effects may never go away, such as in the case of chemotherapy causing permanent damage to the heart, lungs, kidneys, or reproductive system.[1]

References

1.     Chemotherapy Side Effects https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/chemotherapy/chemotherapy-side-effects.html (accessed May 13, 2021).

2.     What is Blood Made Up Of - What is Human Blood Made Up Of https://www.instah.com/health-questions/what-is-human-blood-made-up-of/ (accessed May 13, 2021).

3.     Eldridge, Lynne. What Are the Long Term Side Effects of Chemotherapy for Cancer Treatment https://www.verywellhealth.com/long-term-side-effects-of-chemotherapy-2248994 (accessed May 13, 2021).

4.     Eldridge, Lynne. Secondary Cancer Can Occur After Chemotherapy https://www.verywellhealth.com/what-is-a-secondary-cancer-2249188 (accessed May 14, 2021).