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
Sixteen percent of the breast cancer patients in the
study who had chemotherapy experienced serious adverse chemotherapy-related
health events that resulted in hospitalization or an emergency visit to the
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
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
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
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.