OBJECTIVETo evaluate the response rate and adverse reactions of exemestane (a new aromatase inactivator) in the treatment of postmenopausal women with advanced breast cancer.

METHODSOne hundred and seventy-three patients with advanced breast cancer entered this study with two patients excluded because of postmenopausal time being less than one year. Therefore, 173 patients could be evaluated for adverse events and 171 patients could be evaluated for efficacy. Exemestane, 25 mg orally daily for 4 weeks as one cycle was given.

RESULTSIn the 171 patients evaluated for efficacy, 4 (2.3%) experienced a complete response (CR) and 40 (23.4%) a partial response (PR), with the overall response rate of 25.7%. Ninety patients (52.6%) had stable disease (SD), with 25 having SD for at least 24 weeks. The clinical benefit (CR + PR + SD > or = 24 weeks) was shown in 69 (40.4%) patients. Progressive disease (PD) was shown in 37 (21.6%) patients. The untreated patients had a higher objective response rate (33.8%) than the retreated ones (18.1%) with significant difference (P = 0.019 7). The response rates for soft-tissue, bone involvement and visceral metastasis were 32.8%, 23.9%, and 12.4% (P = 0.002). There was no significant difference in different ages, time of menopause, disease-free interval or receptor status (P > 0.05). Drug-related adverse events were gastric discomfort (17.9%), malaise (17.9%), nausea (13.9%), hot flushes (11.0%) and dysphoria (5.8%). Other side reactions and abnormal laboratory parameters were observed occasionally which were irrelevant.

CONCLUSIONExemestane can be used to treat postmenopausal women with advanced breast cancer giving only mild adverse reactions which are well tolerated.