No, letrozole does not need to be stopped for surgery in breast cancer patients.
Based on current evidence and expert consensus, letrozole can be safely continued through the perioperative period for breast reconstruction and other surgical procedures. 1
Key Evidence Supporting Continuation
The most recent and highest-quality evidence comes from a 2026 systematic review and expert multidisciplinary consensus specifically addressing this question. This comprehensive analysis of anticancer agents and breast reconstruction found that:
- Aromatase inhibitors (including letrozole) do not require preoperative discontinuation for elective breast reconstruction procedures 1
- Expert consensus across plastic surgery, oncology, and breast surgery specialties supports continuing these medications perioperatively
- No specific preoperative laboratory monitoring is required for aromatase inhibitors before surgery 1
Important Caveats and Nuanced Considerations
Wound Healing Concerns
One retrospective study from 2017 raised concerns about increased wound healing complications in patients on hormone therapy during breast reconstruction 2. This study found:
- 61% wound healing complications in patients on hormone therapy vs 28% without (p < 0.001)
- Increased rates of fat necrosis, infections, and delayed wound healing
- However, this study did not differentiate between tamoxifen and aromatase inhibitors, and the mechanism may be more relevant to tamoxifen's estrogenic effects
Why the Difference Matters
Letrozole and other aromatase inhibitors work by blocking estrogen production, whereas tamoxifen has mixed estrogenic/anti-estrogenic effects. The wound healing concerns may be more applicable to tamoxifen than to aromatase inhibitors, though this remains incompletely studied.
Clinical Algorithm for Decision-Making
For routine breast reconstruction or other elective surgery:
- Continue letrozole through the perioperative period
- No washout period required
- No specific preoperative labs needed for the medication itself
Consider temporary discontinuation only if:
- The patient has experienced severe wound healing complications on previous surgeries while taking letrozole
- There are other compelling patient-specific factors (discuss with oncology)
If discontinuation is considered:
- The FDA label provides no specific guidance on perioperative management 3
- Current guidelines emphasize continuous therapy to prevent recurrence 4, 5
- Any interruption should be minimized and coordinated with medical oncology
Common Pitfalls to Avoid
- Don't confuse letrozole with tamoxifen: The thromboembolic risks and wound healing concerns differ between these agents
- Don't stop without oncology consultation: Letrozole is prescribed to reduce breast cancer recurrence risk, which peaks in the first 1-2 years post-diagnosis 6
- Don't assume all hormone therapies are the same: Aromatase inhibitors have a different side effect profile than selective estrogen receptor modulators
Supporting Context from Guidelines
The NCCN guidelines discuss preoperative systemic therapy extensively but provide no recommendation to discontinue adjuvant endocrine therapy for surgery 5. The ASCO guidelines similarly focus on optimal duration and continuation of therapy 4. The absence of any recommendation to stop these medications for surgery, combined with explicit expert consensus supporting continuation, provides strong evidence for the safety of continuing letrozole perioperatively 1.