Life-Threatening Steroid-Refractory Colitis Following One Cycle of Neoadjuvant Immunotherapy and Chemotherapy for Early Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype with a poor prognosis. Neoadjuvant chemotherapy combined with immunotherapy is the standard of care for stage 2-3 breast cancer. This case study describes the clinical history of one patient who experienced profound immune-related adverse events, specifically severe colitis, hepatitis and keratitis following one cycle of neoadjuvant chemotherapy and immunotherapy. The patient was hospitalised and then transferred to a tertiary cancer centre. She needed intensive treatment to treat the colitis, total parenteral nutrition (TPN), three different immunosuppressant drugs, antibiotics, antivirals, and supportive treatment. Breast surgery was performed whilst she was an inpatient, and she did not receive further systemic treatment. In order to avoid significant treatment-related morbidity, better biomarkers predicting immunotherapy toxicity and response are needed to help decide who will benefit from upfront surgery vs. neoadjuvant chemotherapy with immunotherapy.