What is the recommended workup for a patient with breast cancer on TCHP (Taxane, Carboplatin, Trastuzumab, Pertuzumab) presenting with bilateral eye swelling?

Recommended Workup for Bilateral Eye Swelling in Breast Cancer Patient on TCHP

This patient requires urgent ophthalmology consultation and comprehensive evaluation for potential drug-related ocular toxicity, with particular attention to docetaxel-induced canalicular stenosis/epiphora and carboplatin hypersensitivity reactions, while simultaneously ruling out metastatic disease and superior vena cava syndrome.

Immediate Clinical Assessment

Obtain detailed ocular history focusing on:

• Timing of symptom onset relative to TCHP cycles (docetaxel causes cumulative dose-dependent lacrimal duct stenosis) 1
• Presence of tearing/epiphora (excessive tearing is pathognomonic for taxane-induced canalicular stenosis)
• Associated symptoms: vision changes, pain, proptosis, diplopia, or conjunctival injection
• Systemic symptoms: facial swelling, dyspnea, or upper extremity edema (suggesting SVC syndrome from disease progression)

Physical examination must document:

• Periorbital versus generalized facial edema
• Presence of chemosis, proptosis, or extraocular movement restriction
• Dilated neck/chest wall veins (SVC syndrome)
• Cervical/supraclavicular lymphadenopathy
• Signs of hypersensitivity reaction: urticaria, wheezing, or hemodynamic instability 1, 2

Essential Diagnostic Workup

Ophthalmology consultation (urgent, within 24-48 hours):

• Slit lamp examination to assess lacrimal drainage system
• Nasolacrimal duct probing/irrigation to confirm canalicular stenosis
• Evaluation for conjunctivitis, keratitis, or other ocular surface disease
• Intraocular pressure measurement

Laboratory evaluation:

• Complete blood count with differential (thrombocytopenia occurs in 29.8% on TCHP and could contribute to periorbital hemorrhage/swelling) 1
• Comprehensive metabolic panel including albumin (hypoalbuminemia can cause periorbital edema)
• Thyroid function tests (hypothyroidism causes periorbital edema)

Imaging studies:

• Contrast-enhanced CT chest/neck or MRI to evaluate for:
  • Mediastinal/hilar lymphadenopathy causing SVC obstruction
  • Orbital/retro-orbital metastases
  • Cavernous sinus involvement
  • Leptomeningeal disease 3

Differential Diagnosis Priority

Most likely etiologies in descending order:

1. Docetaxel-induced canalicular stenosis (occurs in up to 85% with cumulative dosing, typically bilateral and progressive) 1, 4

2. Carboplatin hypersensitivity reaction (can present as angioedema; risk increases with repeated exposures) 1, 2

3. Disease progression with:

   • Orbital/skull base metastases
   • SVC syndrome from mediastinal disease
   • Leptomeningeal carcinomatosis 3

4. Trastuzumab/pertuzumab-related fluid retention (less common but documented) 5

Management Algorithm

If lacrimal duct stenosis confirmed:

• Continue TCHP if disease control is adequate (stenosis is not life-threatening)
• Ophthalmology management: warm compresses, topical steroids, nasolacrimal duct dilation/stenting
• Consider switching to alternative taxane (paclitaxel or nab-paclitaxel) for subsequent cycles, though cross-reactivity exists 5

If hypersensitivity reaction suspected:

• Hold carboplatin immediately
• Administer antihistamines and corticosteroids
• Consider carboplatin desensitization protocol for future cycles or switch to alternative platinum agent 1

If metastatic disease identified:

• Proceed per HER2-positive metastatic breast cancer guidelines
• Second-line therapy: trastuzumab deruxtecan is preferred 3
• For CNS metastases: consider tucatinib-capecitabine-trastuzumab or trastuzumab deruxtecan (both have CNS activity) 3

Critical Pitfalls to Avoid

• Do not dismiss as simple allergic reaction without ophthalmology evaluation—bilateral progressive periorbital swelling in a patient on taxanes is canalicular stenosis until proven otherwise 1, 4

• Do not delay imaging if any red flags present: unilateral predominance, proptosis, vision changes, or systemic symptoms suggesting SVC syndrome 3

• Do not empirically discontinue all TCHP components—identify the specific causative agent to preserve effective anti-HER2 therapy, as continued HER2 blockade is critical for outcomes 3

• Monitor for progression to complete nasolacrimal duct obstruction requiring surgical intervention (dacryocystorhinostomy) if conservative management fails 4