[Experience of Pembrolizumab Administration in A Patient with Castration-Resistant Microsatellite Instability-High Prostate Cancer].

Castration-resistant prostate cancer and multiple lymph node and ventral bladder metastases in an 87 year-old man progressed despite various systemic therapies, including chemotherapy. Because his prostate surgical specimen displayed a microsatellite instability (MSI) -high status, pembrolizumab 200 mg/body treatment was started. After six courses of treatment, his prostate-specific antigen (PSA) level decreased by 83% versus that at treatment initiation (from 408.78 ng/ml to 69.54 ng/ml), and the para-aortic lymph node metastasis was reduced in size on imaging. After 13 courses, his PSA level (462.59 ng/ml) exceeded that at the start of treatment, and progressive disease was detected on imaging. Although case reports of pembrolizumab for MSI-high prostate cancer remain few because of its rarity, it is an important therapeutic option and further clinical research is required.

Successful management of testicular primitive neuroectodermal tumor with multiple bone metastases.

Introduction: Germ cell tumor with malignant transformation is extremely rare. We present a case of testicular primitive neuroectodermal tumor with multiple metastases that was effectively managed by surgery, irradiation, and second-line chemotherapy. Case presentation: A 22-year-old man was diagnosed as having teratoma including primitive neuroectodermal tumor with lymph node and multiple bone metastases. Five months afterwards the first-line therapy, his skull metastasis recurred. Vincristine, doxorubicin, and cyclophosphamide therapy followed by vincristine, actinomycin D, and cyclophosphamide therapy was given as second-line chemotherapy. Computed tomography revealed no disease progression 3 months after the treatments. Conclusion: Metastatic primitive neuroectodermal tumor may be successfully managed by multidisciplinary cancer treatment.