Stopping Femara (Letrozole) Without PET Scan
You should not stop Femara (letrozole) based solely on the absence of a PET scan—the decision to discontinue hormonal therapy depends on your clinical indication for treatment, treatment duration completed, side effect profile, and disease status, not on whether imaging has been performed. 1
Understanding the Role of PET Scanning in Breast Cancer
PET scanning is not recommended as a routine surveillance tool during or after breast cancer treatment:
- PET/CT should not be used for routine surveillance in breast cancer patients who have completed curative-intent therapy 2
- The increased cost and radiation exposure of PET/CT outweigh any perceived benefit when used as a surveillance modality without proven superiority 2
- PET scanning is primarily reserved for characterizing abnormal findings that are suspicious for recurrence, not for deciding whether to continue or stop hormonal therapy 2
When Letrozole Should Be Continued or Stopped
The decision to stop letrozole is based on clinical factors, not imaging requirements:
Duration-Based Decisions:
- Extended adjuvant therapy: Letrozole after 5 years of tamoxifen has been studied for up to 5 years of additional treatment, showing continued benefit 1
- Standard adjuvant therapy: Treatment duration should follow established protocols for your specific breast cancer stage and receptor status 1
Clinical Factors for Discontinuation:
- Completion of planned treatment duration as determined by your oncologist based on your cancer stage and risk profile 1
- Intolerable side effects including severe bone loss (fractures occurred in 10.4% vs 5.8% placebo at 60 months), cardiovascular events (9.8% vs 7.0% placebo), or severe musculoskeletal symptoms 1
- Disease progression documented by clinical examination, symptoms, or appropriate imaging (not necessarily PET) 1
- Patient unsuitability for continued treatment due to overall health status or patient preference 2
Important Caveats
Do not stop letrozole without consulting your oncologist, even if:
- You haven't had a PET scan 2
- You feel well and have no symptoms 1
- You're experiencing mild side effects that may be manageable 1
Bone health monitoring is critical during letrozole therapy, as fracture rates increase significantly (13.3% vs 7.8% placebo at 62 months follow-up), and bisphosphonates may be indicated 1
The absence of PET imaging is not a reason to discontinue effective hormonal therapy—PET is not part of routine breast cancer surveillance protocols and is not required for treatment decisions in the adjuvant or extended adjuvant setting 2.