Persistence of Oxaliplatin Transfer into Human Milk: A Case Report

Oxaliplatin is an alkylating chemotherapeutic agent commonly used for malignancies in women of reproductive age, including colorectal cancer. No research previously exists regarding the transfer of platinum into milk after administration of oxaliplatin. We present a case of a lactating patient with stage 3a colorectal cancer requiring chemotherapy including oxaliplatin (130 mg/m²) infused every 4 weeks. Milk levels of platinum were tested at Lactation Lab, Inc., using a previously published mass spectrometry method. Milk platinum concentrations 34 and 65 days after treatment were 7.8 and 10.3 ng/mL, respectively. These levels are similar to cisplatin or carboplatin in the immediate weeks after their administration, suggesting that the equivalent platinum exposure risk persists for longer with oxaliplatin than with other platinum analogues. Findings from this report support current recommendations to cease breastfeeding after oxaliplatin administration.