Don't reduce chemotherapy dose for obese women with ER-negative breast Ca

December 1, 2005

It seems obese breast cancer patients are frequently underdosed when it comes to chemotherapy.

It seems obese breast cancer patients are frequently underdosed when it comes to chemotherapy.

Researchers reviewed data from four randomized trials of the International Breast Cancer Study Group assessing the use of adjuvant classical chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil in premenopausal women with node-positive breast cancer.

They found that 39% of obese women received less than 85% of the chemotherapy dose specified by the protocol versus 16% of women with normal or intermediate body mass index. While this didn't significantly compromise outcome in the women with estrogen-receptor (ER)–positive disease, reducing the dose of chemotherapy was associated with a significantly worse outcome in the obese women with ER-negative cancer in terms of disease-free survival (total population hazards ratio ≥ 85% vs. <85%, 0.68, 95% CI; 0.54–0.86, P=0.0013) and overall survival (0.72, 0.56-0.94, P=0.0142).