Supplementary Material for: Long-term and sustained remission of advanced triple-negative breast cancer with large chest wall lesions after transient chemoimmunotherapy: a case report

Abstract
Introduction: Herein, we reported a case of advanced triple-negative breast cancer (TNBC) with special clinical manifestations that achieved durable remission after short-term application of toripalimab combined with chemotherapy. Also, the progress, advantages, and unique experience of chemoimmunotherapy in TNBC was explored. Case Presentation: A case of TNBC with local recurrence 2 years after surgery, with inoperable large chest wall lesions and positive PD-L1 as the main manifestations, was treated with toripalimab combined with paclitaxel (albumin-bound) for 5 months and achieved partial remission. After 25 months post-discontinuation of treatment, the chest wall lesions showed slow but continuous decline until nearly complete remission, the patient eventually died of cancer progression. Conclusion: Typically, chest wall recurrence in TNBC has a poor prognosis. However, the recurrence in this case was rapidly controlled, sustained remission was achieved after immunotherapy combined with chemotherapy, and the curative effect continued after drug withdrawal, which is a rare phenomenon. Thus, the tailing effect of immune checkpoint inhibitors is confirmed in the treatment of TNBC.