Study of Bone Mineral Density in Women With Breast Cancer Treated With Triptorelin and Tamoxifen or Exemestane on Protocol IBCSG 25-02

OBJECTIVES:

• Evaluate changes in bone mineral density (BMD) among premenopausal women randomized in protocol IBC SG-25202 (TEXT-2) to receive either: A) triptorelin (GnRH analogue) for 5 years plus tamoxifen for 5 years; or B) triptorelin (GnRH analogue) for 5 years plus the steroidal aromatase inhibitor exemestane for 5 years.
• Evaluate serial serum markers for bone remodeling (C-telopeptide, osteocalcin, bone-specific alkaline phosphatase) and investigate their correlation with BMD.
• Evaluate the relationship of genetic variants of CYP19A1, ERα, ERß, and IGF 1 with BMD.
• Evaluate serial serum growth factors (IGF-1 and IGFBP-3) and investigate whether their time course correlates with BMD.
• Explore the role of serum IGF-1 and IGFBP-3 as biomarkers of disease outcome (disease-free survival). (exploratory)

OUTLINE: Blood samples are collected at baseline and then periodically for 6 years. Serum markers of bone remodeling and serum growth factor levels are measured.

Bone mineral density in the L1-L4 (postero-anterior) region of the spine and femoral neck of the hip is measured by DEXA at baseline and then periodically for 6 years.

Any surplus serum is stored for use in unspecified future research.

DISEASE CHARACTERISTICS:

• Patient must be eligible and enrolled in the TEXT-2 trial prior to enrolling in TEXT-Bone
• Serial bone marrow density (BMD) measurements must be taken within the same institution
• Hormone receptor positive

PATIENT CHARACTERISTICS:

• See Disease Characteristics
• Premenopausal
• No bone fracture in the past 6 months that, in the investigator's judgement, could be related to bone fragility
• No clinical or biochemical malabsorption syndrome, known vitamin D deficiency, active hyper- or hypoparathyroidism, or Paget's disease
• No uncontrolled thyroid disease, Cushing disease, or other pituitary diseases
• No other bone disease (including osteomalacia or osteogenesis imperfecta)

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• At least 6 months since prior and no concurrent bisphosphonate therapy (or other bone therapies such as PTH or strontium)
• At least 6 months since prior glucocorticoid (> 5 mg prednisone or equivalent) for > 1 month
• At least 12 months since prior anticonvulsants