Should I hold anastrozole (aromatase inhibitor) prior to surgery?

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Last updated: August 17, 2025View editorial policy

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Anastrozole Management Before Surgery

Anastrozole should NOT be held prior to surgery as there is no evidence supporting the need to discontinue aromatase inhibitors before surgical procedures.

Rationale for Continuing Anastrozole

Anastrozole is an aromatase inhibitor commonly used in the treatment of hormone receptor-positive breast cancer in postmenopausal women. Unlike medications that affect coagulation or wound healing, aromatase inhibitors do not pose significant perioperative risks that would necessitate discontinuation.

Key considerations:

  • No bleeding risk: Unlike anticoagulants or antiplatelet agents, anastrozole does not interfere with coagulation pathways
  • No wound healing impairment: There is no evidence that anastrozole negatively impacts surgical wound healing
  • Therapeutic importance: Maintaining hormonal therapy is critical for mortality outcomes in breast cancer patients 1

Evidence from Guidelines

The National Comprehensive Cancer Network (NCCN) and other major oncology organizations do not recommend discontinuing aromatase inhibitors prior to surgery 2. Clinical practice guidelines focus on the importance of maintaining hormonal therapy for optimal breast cancer outcomes.

In postmenopausal patients with hormone receptor-positive breast cancer, guidelines emphasize that "adjuvant endocrine therapy should include an aromatase inhibitor at some point in time" 2. Interrupting this therapy unnecessarily could potentially compromise treatment efficacy.

Potential Risks of Discontinuation

Stopping anastrozole before surgery may pose more risks than benefits:

  • Disease progression: Even short interruptions in hormonal therapy could theoretically allow cancer cell proliferation
  • Treatment efficacy: The consistent suppression of estrogen levels is key to anastrozole's effectiveness 3
  • Treatment adherence: Unnecessary interruptions may affect long-term adherence to therapy

Special Considerations

While anastrozole can be safely continued during the perioperative period, be aware of these considerations:

  • Bone health: Anastrozole increases the risk of osteoporosis and fractures 2, 1. This is particularly relevant for orthopedic procedures but does not require discontinuation
  • Side effect management: Common side effects like joint stiffness and arthralgias may affect post-surgical mobility but generally don't interfere with surgical outcomes 2

Conclusion

Based on current evidence and guidelines, anastrozole should be continued through the perioperative period. The benefits of maintaining hormonal therapy outweigh any theoretical risks associated with continuing the medication during surgery.

If there are specific concerns about a particular surgical procedure, consultation between the surgeon and oncologist is recommended, but the default approach should be to continue anastrozole therapy without interruption.

References

Guideline

Breast Cancer Treatment and Management

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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