Supplementary Material for: An Improvement of exertional dyspnea by the re-introduction of anti-EGFR antibody in patients with metastatic rectal cancer who developed cancerous lymphangiopathy: A case report

Introduction: Re-exposure to anti-EGFR antibodies, such as re-introduction or re-challenge with anti-EGFR antibodies, has attracted much attention in metastatic colorectal cancer. Re-introduction of anti-EGFR antibodies often shows good therapeutic outcomes, as most patients eligible for re-introduction discontinued treatment due to adverse events despite a good treatment response at front-line treatment. We herein report a case of improvement in exertional dyspnea by re-introduction of anti-EGFR antibody in a patient with metastatic rectal cancer who developed cancerous lymphangiopathy. Case presentation: A 68-year-old man who underwent curative surgery for stage IIIB rectal cancer was diagnosed with multiple lung metastases. During late-line treatment, respiratory failure developed due to multiple lung metastases and cancerous lymphangiopathy. Two months after the initiation of irinotecan+cetuximab, which had been discontinued due to acneiform eruptions despite a good treatment response at first-line treatment, his dyspnea and performance status were dramatically improved. Conclusion: This case indicates that re-introduction of anti-EGFR antibody to patients who have discontinued anti-EGFR antibody due to skin toxicity despite a good treatment response is a very useful treatment option for metastatic colorectal cancer.