Aromatase Inhibitor Host Factors Study
Breast Neoplasms
Conditions: official terms
Breast Neoplasms
Conditions: Keywords
Aromatase Inhibitors
Study Type
Study Phase
Study Design
Allocation: Non-Randomized, Endpoint Classification: Pharmacokinetics/Dynamics Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment
Name: Letrozole
Type: Drug
Overall Status
The purpose of this study is to examine how key patient factors, including body size affect how well letrozole suppresses circulating estrogen levels.

This study has two components: (1) Part A - an observational phase to evaluate the impact of vitamin D and obesity on estrogen suppression in post-menopausal women already receiving letrozole treatment, and (2) Part B - an interventional phase for women with body mass index (BM) > 25 kg/m2.

If BMI or other patient factors reduce the effectiveness of letrozole, modifications to treatment recommendations and studies to test higher dosing of letrozole may be needed to maximize the benefit of this treatment and minimize the risk of the breast cancer coming back.
Criteria for eligibility
Healthy Volunteers: No
Maximum Age: N/A
Minimum Age: N/A
Gender: Female
Criteria: Inclusion Criteria:

- Postmenopausal female patients

- histological confirmed diagnosis of estrogen receptor and/or progesterone receptor positive breast cancer (Stage I-III) who have completed local therapy

- Currently prescribed and taking letrozole 2.5 mg daily for a minimum of 3 months

- Willing to provide written informed consent to participate

- for the experimental arm: all of the above and body mass index (BMI) > 25 kg/m2

Exclusion Criteria:

- Known abnormal liver or renal function defined by:

1. Serum Creatinine > 1.25 times institutional upper limit of normal (ULN) or Calculated Creatinine Clearance < 40 mL/min

2. Serum Bilirubin, AST or ALT > 1.5 times ULN

- Presence of persistent local or known metastatic cancer
Mount Sinai Hospital
Toronto, Ontario, Canada
Status: Recruiting
Contact: Pamela J Goodwin, M.D. - 416-586-8605 -
Princess Margaret Hospital
Toronto, Ontario, Canada
Status: Recruiting
Contact: Srikala Sridhar, MD - 416-946-2662 -
Women's College Hospital
Toronto, Ontario, Canada
Status: Recruiting
Contact: Carol Townsley, MD - 416-323-6400 -
Start Date
September 2012
Completion Date
September 2015
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Record processing date processed this data on July 28, 2015 page