According to a study published in Archives of Internal Medicine obese women with breast cancer may be under treated. The retrospective cohort study was conducted to determine treatment patterns in overweight and obese women undergoing adjuvant chemotherapy for breast cancer. Adjuvant chemotherapy is given to women who have no spread of the cancer beyond the primary tumor. This improves the overall survival in the breast cancer patients.
Data on patients with early stage breast cancer treated with adjuvant therapy between 1990 and 2001 was analyzed. This included 9,672 women from 901 practices who were treated with doxorubicin hydrochloride and cyclophosphamide of whom 62 % were above a healthy weight, 31 % were overweight, 17 % were obese and 14 % were severely obese. The quality of the therapy was measured by the use of reduced doses for the first treatment compared with standard doses, dose proportion over the course of the therapy and the relative dose intensity.
First-cycle dose reductions which was defined as a dose proportion of <0.9 compared with standard published doses were administered to 9% of the healthy weight, 11% of the overweight, 20% of the obese, and 37% of the severely obese women. First-cycle reduction was associated with being overweight, obese , severely obese, an age of more than 60 years, and patients with a serious co morbid condition. This finding was related to the fact that physicians may deliberately reduce dosage levels for obese women because of fears of inducing any toxic effects. Dosage of the anti cancer agents are usually calculated based on the body weight.
The authors concluded that by removing deliberate dose reductions treatment with adjuvant chemotherapy would assume importance in the care of overweight and obese women with breast cancer.
Overweight and obese women with breast cancer often receive intentionally reduced doses of adjuvant chemotherapy according to the retrospective study.