Chemo Complications: Underreported?
Researchers Say Estimates of Side Effects for Breast Cancer Chemotherapy Are Too Low
Aug. 15, 2006 -- The potentially serious side effects of chemotherapy appear to be greater for younger breast cancer patients than clinical trials suggest, according to findings from a new study.
Sixteen percent of the breastcancer patients in the study who had chemotherapy experienced serious adverse chemotherapy-related health events that resulted in hospitalization or an emergency visit to the hospital.
More than 8% of chemotherapy patients were treated for infection or fever. Data from clinical trials suggest that just 1% to 2% of patients experience this chemotherapy side effect, researcher Michael J. Hassett, MD, MPH, tells WebMD.
Underestimating the Risk
All of the women included in the study were aged 63 or younger when they were diagnosed with breast cancer.
"All of our previous estimates of chemotherapy side effects among women of this age group have come from clinical trials [designed to assess new drugs]," Hassett says. "We hypothesized that the risk estimates generated in these trials may be too low."
More women have chemotherapy for breast cancer than for any other cancer, and chemotherapy is a leading cause of serious and even life-threatening adverse health events.
Only one previous study has examined the frequency of chemotherapy-related serious side effects in the general population of women treated for breast cancer, and that trial included only women over age 65.
Hassett and colleagues from Harvard Medical School's Dana-Farber Cancer Institute sought to better understand the frequency of chemotherapy-related hospitalizations and ER visits among younger women in their latest study, published in the Aug. 16 issue of the Journal of the National Cancer Institute.
Chemo Side Effects
Using a medical insurance claims database, the researchers compared outcomes within the first year of treatment among 3,526 newly diagnosed breast cancer patients 63 years or younger treated with chemotherapy and an equal number of patients with similar characteristics who did not receive chemotherapy.
Sixty-one percent of chemotherapy patients were hospitalized or were treated at hospital ERs during their first year of treatment, compared with 42% of the patients treated without chemotherapy.
In addition to the larger than previously reported treatment for fever and infections, the researchers documented a higher than previously reported incidence of other chemotherapy-related side effects, including: low white blood cell or platelet counts (5.5% of patients); dehydration and other electrolyte (such as sodium and potassium) disorders (2.5%); nausea, vomiting, or diarrhea (2.4%); general symptoms such as fatigue (2%); and serious blood clots (1.2%).
Compared with chemotherapy patients who did not have treatment-related serious adverse events, medical costs for those who did averaged $13,000 more for hospital care, $406 more for emergency room visits, $16,000 more for outpatient care, and $1,900 more for prescription drugs.