"These results show that preoperative endocrine therapy with aromatase inhibitors offers the same overall objective response and surgery as does chemotherapy in postmenopausal women with locally advanced cancer," said principal investigator Vladimir Semiglazov, MD, head, division of breast cancer, Petrov Research Institute of Oncology, St. Petersburg, Russia.

In his presentation on March 23^rd, Dr. Semiglazov noted that this study is 1 of the first direct comparisons of neoadjuvant endocrine therapy and chemotherapy in the treatment of breast cancer.

The study involved 239 postmenopausal women with oestrogen receptor-positive breast cancer that was either progesterone receptor-positive or -negative, and was at stage T2 with involvement of 1 to 2 lymph nodes, stage T3 with no more than 1 node involved, or T4 with no nodal involvement.

Patients were randomised to preoperative treatment with either an aromatase inhibitor -- consisting of either anastrazole (Arimidex) or exemestane (Aromasin) -- or chemotherapy.

The 121 patients treated with aromatase inhibitors were further randomised to receive either 1 mg daily of anastrozole (61 patients), or 25 mg of exemestane daily (60 patients). Patients were treated for 3 months.

In the chemotherapy group, 118 patients received 60 mg/m² of doxorubicin and 200 mg/m² of paclitaxel every 3 weeks for 4 cycles.

Study end points were overall objective response -- determined by palpation, mammography, and ultrasound. The researchers also gathered information on how many patients qualified for breast-conserving surgery and radiotherapy, and how many required mastectomy.

In the overall group, 62.2% of the endocrine therapy group and 63.5% of the chemotherapy group responded to treatment. Median time to clinical response was 57 days in the endocrine group and 51 days in the chemotherapy group.

Pathologic complete response was achieved in 3.2% of patients in the endocrine group and 5.9% of those on chemotherapy. Of patients on endocrine therapy, 9.0% and 8.5%, respectively, had disease progression. None of these differences were statistically significant, Dr. Semiglazov said.

He concluded that the study's findings show an encouraging potential for the use of aromatase inhibitors in the neoadjuvant setting for certain patients with locally advanced disease.


[Presentation title: Primary Endocrine Therapy Vs Chemotherapy in Postmenopausal ER-Positive Breast Cancer Patients. Abstract 238]

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