Amrubicin is effective against small cell carcinoma of the prostate as a second-line chemotherapeutic agent: A case report

Introduction Small cell carcinoma of the prostate has a poor prognosis. Furthermore, treatments for small cell carcinoma of the prostate have not been established. We report a case where amrubicin was effective for second-line chemotherapy. Case presentation A 50-year-old man complaining of painful micturition was referred to our hospital. Due to high prostate-specific antigen level (16.57 ng/mL) and abnormal magnetic resonance imaging findings (cT2c), prostate biopsy was performed; mixed adenocarcinoma and small cell carcinoma of the prostate were observed. Radical prostatectomy was performed following a cT2cN0M0 diagnosis. One month after prostatectomy, fluorodeoxyglucose positron emission tomography/computed tomography showed metastatic lesions in the bone; the patient received androgen deprivation therapy and two cycles of cisplatin plus irinotecan. Due to new metastatic lesions and sustained abnormal pro-gastrin-releasing peptide levels, amrubicin was administered for second-line chemotherapy. Pro-gastrin-releasing peptide was normalized and positron emission tomography/computed tomography showed a complete metabolic response after 15 cycles of amrubicin. Conclusion Amrubicin could serve as a second-line chemotherapeutic agent against small cell carcinoma of the prostate.