Unraveling the Crimson puzzle: Two case reports/case series of hemorrhagic cystitis after combination chemotherapy with docetaxel, carboplatin, trastuzumab and pertuzumab in breast cancer.

RATIONALE: Hemorrhagic cystitis can be a serious side effect of some chemotherapy drugs like cyclophosphamide and ifosfamide. Docetaxel is a taxane that is used to treat several malignancies including breast and prostate cancer. Hemorrhagic cystitis has not been described as a complication of combination chemotherapy with docetaxel, particularly docetaxel with carboplatin, trastuzumab and pertuzumab (TCHP) in breast cancer patients.

PATIENT CONCERNS: Both patients had a history of locally advanced human epidermal growth factor receptor 2 positive breast cancer and complaint of hematuria after their first treatment with TCHP.

DIAGNOSES: They were diagnosed with hemorrhagic cystitis.

INTERVENTIONS: Docetaxel was discontinued and changed to paclitaxel.

OUTCOMES: Both patients completed neoadjuvant chemotherapy and did not have further episodes of hemorrhagic cystitis.

LESSONS: Hemorrhagic cystitis is a rare complication of combination chemotherapy with docetaxel (TCHP). Clinicians should be vigilant for signs and symptoms of hemorrhagic cystitis in patients receiving docetaxel and alternative treatment option should be considered.