Cancer develops when normal cells within the body begin to proliferate rapidly and uncontrollably, giving rise to unlimited numbers of cells and forming tumors. Cancer therapies aim to remove cancerous tumors through surgery, and/or control further cancer cell growth through the use of cancer drugs or radiation therapy. Often, aggressive cancer therapies also affect normal tissues throughout the body, so cancer patients may experience a number of unpleasant side effects as a result of cancer treatment.
Neutropenia
One possible side effect of cancer therapy is neutropenia, a disease characterized by dangerously low white blood cells. Since white blood cells make up part of the immune system and function to fight off disease, patients with neutropenia are vulnerable to infection. Neutropenia develops as a result of damage to bone marrow cells that normally give rise to white blood cells. Cancer therapies such as chemotherapy, or radiation to the bone marrow, target and kill bone marrow cells. Without functioning bone marrow cells, the body cannot make enough new white blood cells, and the patient develops neutropenia. Cancer patients suffering from neutropenia may receive medications called colony-stimulating factors that increase white blood cell counts, according to the Merck Manuals.
Mouth Sores
Another possible side effect of cancer therapy is the development of mouth sores, reports MayoClinic.com. This effect often develops in response to chemotherapy, since chemotherapy drugs target proliferating cells within the lining of the mouth. Under normal conditions, these cells proliferate to repair and replenish tissue in the mouth. When chemotherapy damages cells within the mouth lining, the tissue cannot adequately repair itself, and the patient begins to develop a number of open sores. Patients suffering from mouth sores experience pain eating or swallowing, and may also develop sores in the stomach lining and esophagus. Some patients may receive medication to reduce the risk of developing mouth sores after chemotherapy to allow for proper eating and increase the patient's quality of life.
Infertility
Some cancer therapies to treat tumors in the pelvis or lower abdomen may lead to infertility. Some forms of cancer, such as testicular cancer, prostate cancer, uterine or cervical cancer, or ovarian cancer, directly affect the reproductive system. Patients with cancer of the reproductive system commonly undergo surgery to remove the affected organs, damaging the reproductive system and affecting fertility. In other cases, radiation therapy to treat cancer within the pelvis can affect the testes in men or the ovaries in women. Both the testes and ovaries are extremely vulnerable, and exposure to radiation during radiation therapy can damage the cells that produce sperm or eggs. As a result, patients receiving radiation therapy in the pelvis, such as radiation to treat prostate cancer, may suffer from temporary or permanent infertility after treatment, according to the University of California, San Francisco.
