Rectal cancer may also be referred to as colorectal cancer, which encompasses colon and rectal cancer, according to the American Cancer Society. The rectum is the last six inches of the digestive system where stool is held until it is excreted, and cancer that forms in this area is called rectal cancer. Rectal, or colorectal cancer, can be treated in a variety of ways, including chemotherapy, which is the use of medications and drugs to help kill cancer cells. Commonly used drugs to treat rectal cancer include 5-FU, oxaliplatin, capecitabine and irinotecan. Side effects of chemotherapy vary depending on the drug, the dosage given and the chemotherapy regimen. Not everyone will experience every side effect, and most resolve once treatment has ended and are easily managed.
Irinotecan (Camptosar)
This drug is used in the FOLFIRI chemotherapy regimen with 5-fluorouracil (5-FU) and leucovorin, which is a first-line treatment for advanced colorectal cancer, according to the American Cancer Society. A notable side effect of this medication is that in some people this drug cannot be broken down, so the drug accumulates in the body and causes adverse side effects. To see if your body can break irinotecan down, your doctor may do a blood test that checks for bilirubin levels; this can indicate whether you will have a problem with this drug because of increased sensitivity. Other primary side effects of this medication include severe diarrhea, low white and red blood cell counts (which can lead to increased risk of infection and anemia) and nausea.
5-Fluorouracil (5-FU) and Capecitabine (Xeloda)
The drug 5-FU is typically given with leucovorin to increase its effectiveness, and is commonly used to treat colorectal cancer, according to the American Cancer Society. Side effects of this drug include nausea, diarrhea, loss of appetite, mouth sores, lowered white and red blood cell counts and sensitivity to sunlight. Hand-foot syndrome may also occur in some people, which is when the palms of the hands and soles of the feet become very sensitive, start to peel or blister and turn red.
Capecitabine changes to 5-FU when it is in the body and reaches the cancer. The side effects are similar to those of 5-FU, although they are typically less common. Hand-foot syndrome may be seen more with capecitabine than 5-FU.
Oxaliplatin (Eloxatin)
Oxaliplatin is typically used with 5-FU and leucovorin in the FOLFOX chemotherapy regimen, and with capecitabine in the CapeOX chemotherapy regimen. This medication typically causes nausea and vomiting, diarrhea, mouth sores, abdominal pain, fatigue, difficulty breathing and numbness of the lips. Peripheral neuropathy is also common with this drug, which is when damage to the nerves in the feet and hands occurs. Symptoms of peripheral neuropathy include tingling in the hands and feet similar to "pins and needles." Less common side effects include lowered white and red blood cell counts, trouble swallowing, and sensitivity to cold temperatures.
