About 70 percent of colorectal cancers (CRC) develops in patients over the age of 65. Treatment options in these elderly patients include the use of single-agent or combination-based chemotherapies. However, elderly patients are particularly vulnerable to side effects, especially when drugs are used in combination, according to a new study.
Researchers used a large population-based database with Medicare-linked information to identify 46,692 patients 65 years of age or older with CRC. Medicare data were used to determine what types of chemotherapy, if any, these patients received. There were 5 categories of patients: no intravenous chemotherapy (77.4 percent), fluorouracil (5-FU) alone (11.7 percent), oxaliplatin-based (4.9 percent), bevacizumab-containing chemotherapy (2.8 percent), and other chemotherapy (3.2 percent). Adverse events and toxicities, including abnormal laboratory profiles, were identified.
Patients who received chemotherapy tended to be younger, had more advanced cancers, and were more likely to be married compared to patients who did not get chemotherapy. All patients, whether receiving chemotherapy or not, had a high incidence of symptoms and laboratory test abnormalities, which increased after patients began receiving chemotherapy. Compared to patients on 5-FU alone, those on an oxaliplatin-based regimen had higher rates of adverse events, including nausea and neuropathy. Those 70 years of age and older were more likely to experience certain adverse events such as infection, anemia, delirium, and heart disease.
The study was supported in part by AHRQ (HS16743). See "comparison of toxicity profiles of fluorouracil versus oxaliplatin regimens in a large population-based cohort of elderly patients with colorectal cancer," by Putao Cen, M.D., Chih-Chin Liu, Ph.D., and Xianglin L. Du, M.B., M.S., Ph.D., in the June 2012 Annals of Oncology 23(6), pp. 1503-1511.