When cancer attacks a part of the body, it does so by rapidly dividing abnormal cancerous cells. Chemotherapy, commonly referred to as "chemo," treats cancer with drugs intended to destroy cancer cells, slow down their rapid proliferation and prevent them from spreading to other parts of the body. According to the National Cancer Institute, chemotherapy can be administered through a variety of methods and used alone or in conjunction with other treatments. Side effects of chemo result from the fact that the treatment destroys rapidly dividing cells regardless of whether they are cancerous or non-cancerous.
Hematological Side Effects
According to the American Cancer Society (ACS), chemotherapy destroys blood cells rapidly produced by the bone marrow, including red blood cells, white blood cells and platelets. This condition is called bone marrow suppression and the decreased number of blood cells accounts for the physical side effects a person on chemo experiences.
Red blood cells have hemoglobin and function as oxygen carriers to all cells of the body. Low red blood cell levels cause anemia, which results in fatigue, weakness or difficulty breathing. This is because the body is not receiving enough oxygen.
White blood cells, especially a type called neutrophils, function as an "army" that fights off infection. The ACS says a condition called neutropenia, or abnormally low neutrophils, puts people with cancer at an increased risk for infection, which could be life-threatening.
Platelets respond when there is a cut on the body and they plug off the injured site with a clot to prevent continuous bleeding. Abnormally low levels of platelets, or thrombocytopenia, increases the risk for excessive and uncontrolled bleeding. The ACS also says low platelet counts caused by chemotherapy are temporary but can result in bruising easily, nosebleeds or visible blood in the stool and urine.
Gastrointestinal Side Effects
When chemo affects cells of the digestive tract the resulting side effects include nausea, vomiting and diarrhea. According to Gralla, Houlihan and Messner, authors of "Understanding and Managing Chemotherapy Side Effects" from Cancer Care Connect, the presence of these side effects depends on which chemo drug has been used. Anti-emetic, or anti-nausea, medications are administered along with chemotherapy to prevent and manage the symptoms. Other issues relating to the gastrointestinal system are altered taste, loss of appetite, weight changes and sores on the mouth or throat. The ACS attributes these effects to chemo changing taste receptors, altering the body's metabolism and damaging cells lining the interior of the mouth. Certain chemo drugs can also cause constipation.
Neurological Side Effects
Chemotherapy can sometimes cause nerve damage over time, which leads to pain, tingling and numbness of the extremities. Gralla, Houlihan and Messner say that symptoms stemming from nerve damage can include difficulty with fine motor tasks such as picking up small objects, trouble walking and balancing, jaw pain or hearing loss.
Dermatological Side Effects
Hair loss, or alopecia, is a side effect most feared by people diagnosed with cancer, according to the Mayo Clinic. The extent of hair loss can vary depending on the type and dosage of the chemo drug; there may be some thinning of the hair or baldness. Most cases of alopecia are temporary and can affect the hair follicles all over the body. Dr. Eric Winer, director of the Breast Oncology Center, Dana-Farber Cancer Institute and Brigham and Women's Hospital, reported on ABC News that the skin and nails can also be affected by chemotherapy. Skin changes can include a rash, sensitivity or peeling. Nails may appear swollen and eventually fall off without much pain.
References
- National Cancer Institute: Understanding Chemotherapy
- American Cancer Society: What Are the Possible Side Effects of Chemotherapy?
- "Understanding and Managing Chemotherapy Side Effects"; Richard J. Gralla, M.D., Nancy G. Houlihan, R.N., M.A., AOCN, Carolyn Messner, DSW; 2010
- Mayo Clinic: Chemotherapy and Hair Loss--What to Expect During Treatment
- ABC News Health: Can Chemotherapy for Breast Cancer Affect My Skin and Nails?
