News from Breast Cancer Res and Treat 2001

Letrozole as Primary Medical Therapy for Locally Advanced Breast Cancer and Large Breast Cancer.

[By: JM Dixon, CDB Love, COC Bellamy, DA Cameron, RCF Leonard, H. Smith, and WR Miller]

OBJECTIVE
To investigate the effectiveness of letrozole 2.5 mg and 10 mg used as primary neoadjuvant therapy in patients with locally advanced breast cancer and large operable breast cancer.

Patients and Methods
Twenty-four postmenopausal patients with locally advanced and major breast cancer were given two series of letrozole 2.5 mg (n=12) or letrozole 10 mg (n=12). Response after 3 months was assessed by measuring tumor volume according to WHO criteria (partial response is defined as a decrease in tumor volume > 65%). Tumor volume was assessed clinically, ultrasonographically and mammographically as well as pathologically.

Results
The 24 patients showed positive estrogen receptors, and were termed "receptor rich", with an average age of 77.6 years and 71.6 years in the 2.5 mg letrozole and 10 mg letrozole groups, respectively. There were 5 people with complete clinical response and seven partial clinical responses in patients with 2.5 mg letrozole. There were 9 partial responses and 3 patients with stable disease in the letrozole 10 mg group. Ultrasound and mammographic assessment showed that, of the 12 patients who received 2.5 mg letrozole, there was 1 complete response, 9 partial responses and 2 with no change. In patients receiving 10 mg letrozole, there were 8 partial responses and 4 without change. A patient who received a dose of 2.5 mg experienced a complete and pathological clinical response.

Conclusion
Letrozole used as a neoadjuvant is very effective, resulting in a reduction in tumor volume clinically that allows patients to undergo breast conserving surgery, with an acceptable safety profile.