Obese Breast Cancer Patients May Get Sub-par Chemo

NEW YORK (Reuters Health) - Overweight and obese women with breast cancer often receive reduced doses of chemotherapy after surgery or radiation, new research indicates. Giving full weight-based doses to such women would probably improve treatment outcomes.

Previous reports have shown that heavy women with breast cancer fare worse than their lean counterparts. One reason for this difference could be that, because of the fear of severe side effects, doctors are not giving obese patients a chemotherapy dose based on their weight.

To look into the treatment of obese and overweight women, Dr. Jennifer J. Griggs, from the University of Rochester in New York, and colleagues analyzed data from 9672 women with breast cancer who were treated with standard chemo between 1990 and 2001.

Sixty-two percent of the participants were overweight or obese, according to the team's report in the Archives of Internal Medicine.

The percentage of women who got a reduced dose of chemotherapy during the first cycle increased with each successive weight group, ranging from 9 percent of normal-weight subjects to 37 percent of severely obese subjects.

In addition to being overweight or obese, age over 60 years and the presence of another serious condition both increased the likelihood that a woman would be given a reduced dose of chemo, the investigators report.

Among patients given a full weight-based dose, severe obesity was associated with a lower risk of developing a fever and low white-cell count, the report indicates. This suggests that the concerns about toxicity some clinicians may have when treating obese patients with a full dose may be unfounded.

"The incidence of obesity, particularly severe obesity, is increasing in the US," the authors point out. "Eliminating unwarranted dose reductions will therefore become increasingly important in defining best practices for the care of overweight and obese women."

SOURCE: Archives of Internal Medicine, June 13, 2005.