Overnight fasting serum cholesterol, HDL, LDL and triglycerides levels and bone mineral density (BMD) values during adjuvant letrozole in daily practice.

Abstract

11040 Background: Background: Randomized clinical trials (RCT’s) have demonstrated a superiority of adjuvant aromatase inhibitors (AI’s) over tamoxifen (TAM) in disease free survival and overall survival, immediately postoperatively, in cross-over or extended setting in hormone receptor positive BC. In these studies AI’s were associated with increased bone demineralization and a rise in non- fasting serum cholesterol. Patients and methods: The tolerance for adjuvant letrozole was reviewed in 185 postmenopausal women with hormone receptor-positive early BC including fasting cholesterol levels and bone mineral density (BMD) values. Results: 121 patients (pts) received first-line adjuvant letrozole and 64 pts were crossed over from TAM. Median follow-up was 26 months (15–63 mths). Median age was 56 yrs (37–85y). Median time on letrozole was 23 months. Forty three of the 185 (24 %) of the pts discontinued the adjuvant therapy with letrozole (after a median duration of treatment of 5 months (1wk-30mths)), because of intolerance (83.7%)and PD in 16.3%. Median overnight fasting serum cholesterol levels did not change significantly (p=0.4) over a 2 year observation period from (203.5 mg/dl (131–342)) baseline to (205.5 mg/dl (151–330)) follow-up in 32 evaluable (14/32 pts prior TAM) pts. Median HDL levels rose from 65.5 mg/dl (38–107) to 70 mg/dl (38–103) (p=0.03) after 2 years, but LDL levels did not rise significantly. In the contrary triglycerides levels decreased from 122.5 mg/dl (48–238) to 105 mg/dl (47–285) (p=0.01). Despite the use of upfront biphosphonates in 1/3 of the pts, loss of BMD was significant for the lumbar spine after 2 years in 22 evaluable (8/22 prior TAM) pts (median T-score decreased from minus 0.3 to -0. 45, p=0.02), but not for the hip. Conclusion: Adjuvant letrozole did not significantly increase overnight fasting serum cholesterol levels in daily practice. Adjuvant letrozole was associated with a significant rise in HDL levels and a significant decrease in triglycerides levels after 2 years of therapy. Loss of BMD was observed in concordance with results from RCT’s. Adjuvant letrozole had to be discontinued prematurely because of tolerance issues in 20 % of the pts. No significant financial relationships to disclose.