SOURCE: Rutgers Cancer Institute of New Jersey, news release, July 2, 2015.
MONDAY, July 6, 2015 (HealthDay News) -- Ovarian cancer patients who are overweight or obese are often given lower doses of chemotherapy per pound of body weight, but this may reduce the odds of survival, a new study suggests.
"There is a lot of uncertainty in what proper chemotherapy dosing levels should be for overweight and obese patients, based on concerns that using the full dose based on weight or body size could be too toxic," study author Dr. Elisa Bandera, an epidemiologist at Rutgers Cancer Institute of New Jersey, explained in an institute news release.
"Our study is the first to evaluate the impact of dose reduction in survival after an ovarian cancer diagnosis in normal weight, overweight and obese women," Bandera said. "We found that for each body mass index category, ovarian cancer patients with dose reduction experienced a poorer survival rate."
The study involved 806 women with ovarian cancer who were treated with a combination of the chemotherapy drugs paclitaxel and carboplatin. Researchers examined information compiled about the women in electronic medical records and other clinical and administrative databases.
Of the women, 30 percent were obese, while 31 percent were overweight. Fewer than 3 percent were underweight, the study published online July 2 in the journal JAMA Oncology found.
The obese women received less of the chemotherapy drugs per pound of body weight, compared to the women who were a normal weight.
The researchers said lower doses were linked with lower survival rates. Patients with an average dose reduction of up to 85 percent had a 35 percent greater risk for death than those who received the standard dosing, the study found.
However, the study did not prove a cause-and-effect link between lower chemotherapy dose and death risk.
The American Society of Clinical Oncology recommends giving breast cancer patients full doses of chemotherapy based on their weight. The study authors said their findings suggest these guidelines should also apply to women with ovarian cancer.
"Our observations suggest that body size should not be a principal reason for reducing chemotherapy dose in women with ovarian cancer," senior study author Lawrence Kushi, an epidemiologist at the Kaiser Permanente Northern California Division of Research, said in the news release.
The American Cancer Society provides more information on ovarian cancer.