Breast Cancer Chest Wall Recurrence Management

A postmastectomy chest wall recurrence:
- Carries a high risk of concurrent or subsequent distant disease:
  - So the first steps are:
    - Tissue confirmation with receptor reassessment (ER / PR and HER2) and systemic staging to establish whether the recurrence is truly isolated:
      - Which determines whether curative-intent multimodality therapy versus palliative systemic therapy is appropriate
High risk of concurrent systemic disease:
- Staging First:
  - In the ACOSOG / Alliance AFT-01 study of stage II to III patients:
    - Synchronous distant metastases were present in 27% overall at the time of locoregional recurrence:
      - 30% specifically for postmastectomy chest wall recurrence
      - 35% for nodal
      - 15% for in-breast
  - A separate cohort found distant metastases in:
    - ~32% of patients at diagnosis of locoregional recurrence
- This justifies obtaining systemic staging and receptor status before committing to local therapy
NCCN staging modalities — confirmed with nuance:
- NCCN workup for recurrent disease (BINV-18) includes:
  - History / physical
  - CBC, comprehensive metabolic panel with LFTs and alkaline phosphatase
  - Imaging:
    - Chest diagnostic CT ± contrast
    - Abdomen ± pelvis CT with contrast or MRI
    - Bone scan or sodium fluoride PET / CT (category 2B):
      - With FDG-PET/CT “useful in certain circumstances” (and FES-PET/CT considered for ER-positive / lobular disease)
    - Brain and spine MRI are reserved for relevant symptoms
    - So PET/CT is positioned as an option in select circumstances rather than fully interchangeable with CT + bone scan
  - Critically, NCCN also mandates biopsy of the recurrence with re-evaluation of ER / PR and HER2:
    - Because receptor status can discordantly change between primary and recurrence
Surgical excision to negative margins + comprehensive chest wall / nodal RT — confirmed:
- For an isolated chest wall recurrence after mastectomy, NCCN (BINV-19) recommends:
  - Consider appropriate systemic therapy to best response if indicated, then surgical resection if feasible + consider surgical axillary staging + post-mastectomy RT (radiation-naïve patients), or repeat RT if feasible and indicated in previously irradiated patients
- Corroborating data:
  - The DEGRO guideline calls:
    - Complete (R0) resection followed by chest wall RT with strongly advised regional nodal irradiation the standard, using 50 to 50.4 Gy ± 10 Gy boost
- A retrospective series of isolated chest wall recurrences found chest wall plus RNI significantly improved progression-free and overall survival versus chest wall RT alone:
  - Supporting comprehensive nodal coverage
Multidisciplinary management — confirmed:
- NCCN explicitly emphasizes that a multidisciplinary approach is especially important in recurrence to consider all treatment options
- Involvement of a plastic / reconstructive surgeon is appropriate when full-thickness chest wall resection and reconstruction are needed
CALOR trial — confirmed, with updated final numbers:
- The final analysis (median 9-year follow-up, 162 patients):
  - Confirmed a significant chemotherapy benefit for ER-negative isolated locoregional recurrence (DFS HR 0.29, 95% CI 0.13–0.67; 10-year DFS 70% vs 34%) but no benefit for ER-positive recurrence (HR 1.07, 95% CI 0.57–2.00; 10-year DFS 50% vs 59%; P-interaction = 0.013)
  - The overall survival interaction was not significant (P = 0.53)
  - This refined the earlier 2014 Lancet Oncology report:
    - Which had shown an overall DFS benefit (HR 0.59) driven by the ER-negative subgroup
Systemic therapy:
- Is tailored to receptor status of the recurrence, not just chemotherapy
- All hormone receptor-positive recurrences:
  - Should receive endocrine therapy:
    - Which is standard of care and improves disease-free survival:
      - SAKK 23/82 established tamoxifen’s role
  - HER2-positive recurrences:
    - Should receive HER2-targeted therapy
    - Chemotherapy is the component that CALOR showed benefits specifically ER-negative disease:
      - Emerging data qualify the “no chemo for ER-positive” message
- A 2025 multi-institutional retrospective cohort of 958 patients with HR-positive / HER2-negative locoregional recurrence:
  - Found adjuvant chemotherapy associated with better invasive DFS (HR 0.70), particularly for non-IBTR recurrences and recurrences during adjuvant endocrine therapy:
    - Though with a worse trend in overall survival and the caveats of retrospective design
- Genomic assays (e.g., Oncotype DX) are being explored to identify HR-positive patients who can safely omit chemotherapy
- The POLAR trial is evaluating palbociclib in HR-positive recurrences
- These do not overturn CALOR but reflect evolving practice
Reirradiation is now a more established option for previously irradiated patients:
- Modern techniques (IMRT, proton therapy, brachytherapy, hyperthermia, ± radiosensitizers):
  - Achieve local control of ~ 60% to 75% with acceptable toxicity, with the decision factoring in prior dose, interval since prior RT, and cumulative normal-tissue toxicity
NCCN cautions the same:
- Truly unresectable or widespread systemic disease shifts management to palliative systemic therapy per the metastatic algorithms (BINV-21 onward) rather than curative local therapy
References:
- NCCN Clinical Practice Guidelines in Oncology, Breast Cancer, Version 6.2026