Supplementary Material for: Differentiating between laryngopharyngeal dysesthesia and hypersensitivity reactions to oxaliplatin and addressing dyspnea: Two case reports

Oxaliplatin is a key drug for colorectal cancer and causes peripheral neuropathy. Oxaliplatin-induced laryngopharyngeal dysesthesia is an acute peripheral neuropathy similar to a hypersensitivity reaction. Hypersensitivity reactions to oxaliplatin do not require immediate discontinuation, but re-challenge and desensitization therapy can be very burdensome for patients. We encountered two cases in which laryngopharyngeal dysesthesia could be differentiated from hypersensitivity reactions to oxaliplatin, and treatment could continue. The first case was that of a 58-year-old woman who developed dyspnea during the first course of combination therapy with capecitabine and oxaliplatin as the primary treatment for advanced rectal cancer. After laryngopharyngeal dysesthesia was differentiated from hypersensitivity reaction based on these typical symptoms, she was considered to have grade 3 (Common Terminology Criteria for Adverse Events (CTCAE) ver.5) laryngopharyngeal dysesthesia. The second course of oxaliplatin was extended from two to four hours, but symptoms recurred. The third course was performed with a reduced dose of oxaliplatin from 130 mg/m2 to 100 mg/m2, and the patient could complete the treatment without symptom recurrence. The second case involved a 76-year-old woman who developed grade 3 laryngopharyngeal dysesthesia during the first course of combination therapy with capecitabine and oxaliplatin as the primary treatment for localized colon cancer. Based on the experience of the first case, we reduced the oxaliplatin dose from 130 mg/m2 to 100 mg/m2 for the second course, and the patient completed the treatment without symptoms. This dose reduction was effective for grade 3 laryngopharyngeal dysesthesia caused by oxaliplatin without reducing therapeutic efficacy.