This is a prospective clinical study enrolling eligible subjects scheduled to receive oxaliplatin-based chemotherapy after signing informed consent forms.
Subjects are randomly assigned to two groups. Group 1 (skin test group) receives an intradermal injection of 0.02 mL oxaliplatin solution (0.01-5.00 mg/mL) before cycles 6-10 (oxaliplatin-naive patients) or cycles 2-6 (patients with recurrence after adjuvant oxaliplatin chemotherapy), with a simultaneous self-negative control (0.02 mL 0.9% normal saline). A total of 1650 person-times will be included. Group 2 (negative control group) includes 50 subjects who receive 0.02 mL 0.9% normal saline intradermally before cycle 6 or 2.
Assessments include:
1. Skin test results evaluated 15-30 minutes post-injection; a positive result is defined as a wheal ≥5 mm with surrounding erythema
2. Maximum diameter of skin test rash measured 15-30 minutes post-injection
3. Biomarker detection at three time points: pre-initial skin test, 1 hour post-skin test, and 1 hour post-first medication (carboxypeptidase A3, 9α,11β-PGF2, cysteinyl leukotrienes LTC4/LTD4/LTE4, IL-4/5/1β/6/8, TNF-α, MCP-1, mast cell chymase, total tryptase, ΔTryptase, ΔIL-6 peak); pre-skin test assessments include basophil activation rate, total IgE, LDH, lymphocytes, monocytes, and eosinophils
4. Occurrence, onset time, severity (graded per NCI-CTCAE Version 5.0), and classification of oxaliplatin infusion-related hypersensitivity reactions Follow-up continues until cycle 10 (cycle 6 for oxaliplatin re-exposed patients) or the first occurrence of: hypersensitivity reaction, disease progression requiring new anti-tumor therapy, intolerable toxicity, consent withdrawal, loss to follow-up, death, or other protocol-specified termination conditions.
The negative control group is exclusively used for exploratory biomarker correlation analysis to assess the impact of skin test procedures, and is excluded from primary (sensitivity, specificity) and secondary (predictive values, likelihood ratios, Kappa coefficient) endpoint analyses. Limitations of this exploratory analysis are explicitly stated.
Biomarker correlation analysis uses first skin test baseline data from 50 subjects per group (total 100 randomized cases). Variable block stratified randomization is performed, stratified by oxaliplatin-naive status and presence of comorbidities (diabetes, hypertension, renal insufficiency).