Should Letrozole Be Stopped Until Recovery from Femur Fixation Surgery?
Letrozole should generally be continued through femur fixation surgery without interruption, as there is no evidence that temporary discontinuation improves surgical outcomes, and stopping adjuvant endocrine therapy risks compromising breast cancer control—the primary determinant of mortality and quality of life.
Rationale
Bone Fracture Risk Context
Letrozole is associated with increased bone fracture risk in breast cancer patients. The ASCO guidelines 1 document that extended aromatase inhibitor therapy increases fracture odds (OR 1.34, NNH 72) with bone fracture rates of 14% versus 9% compared to placebo in the MA.17R trial. However, this increased fracture risk is already established and does not provide justification for stopping the drug perioperatively.
No Evidence Supporting Perioperative Discontinuation
Neither the ASCO guidelines 1 nor the FDA label 2 recommend stopping letrozole for surgical procedures, including orthopedic surgery. The drug's mechanism—aromatase inhibition leading to estrogen depletion—does not create acute perioperative risks that would be mitigated by brief discontinuation.
Prioritizing Breast Cancer Outcomes
The primary concern must be breast cancer recurrence prevention, which directly impacts mortality. The ASCO guidelines 1 emphasize that extended letrozole therapy reduces disease recurrence (HR 0.66 for disease-free survival in MA.17R). Interrupting therapy—even briefly—introduces unnecessary risk to cancer control without documented benefit for fracture healing.
Surgical Healing Considerations
While one retrospective study 3 suggested letrozole may increase hernia rates after TRAM flap reconstruction (13.5% vs 3.9%), this finding:
- Applies to abdominal wall healing, not long bone fractures
- Represents a single center's experience
- Does not establish causation for impaired femur fracture healing
Animal studies 4 show letrozole affects bone biomarkers and increases fracture risk chronically, but provide no evidence that short-term discontinuation improves acute fracture healing.
Clinical Approach
Continue letrozole through the perioperative period with these considerations:
- Optimize bone health: Ensure adequate calcium (500 mg daily) and vitamin D (400 U daily) supplementation as recommended in bone density studies 5
- Monitor for complications: Standard postoperative fracture healing assessment
- Consider bisphosphonates: If not already prescribed, discuss with oncology for patients with osteoporosis (T-score < -2.0)
- Coordinate care: Inform orthopedic team of letrozole use, but this should not delay surgery
Common Pitfall to Avoid
Do not delay femur fracture surgery to "optimize" by stopping letrozole. The evidence shows anticoagulated patients already experience harmful delays 6, and there is no parallel evidence that letrozole discontinuation improves outcomes. Early surgical fixation (within 24 hours) remains the priority for reducing morbidity and mortality from hip fractures.
The modest increase in long-term fracture risk from letrozole (already manifested by the current femur fracture) does not justify compromising breast cancer treatment continuity for unproven perioperative benefit.