[Three Cases of High-Grade Malignant Cancer of Unknown Primary with a Long-Term Survival]

We report 3unusual cases of cancer of unknown primary(CUP)with a long-term survival after chemotherapy. A 56-yearold man was diagnosed as having CUP with invasion of an enlarged carcinoma 20 cm in size to the pancreas and peritoneal dissemination. He received chemotherapy with paclitaxel, carboplatin, and gemcitabine. After the chemotherapy, CT scan and PET-CT revealed no evidence of disease, so tumor resection was performed. The subsequent pathological findings revealed no cancer and a complete pathological response. The patient is currently alive 4 years after the first surgery, without evidence of recurrence and adjuvant chemotherapy. A 60-year-old man was diagnosed as having CUP with an undifferentiated carcinoma and lymph node metastasis. He received chemotherapy with paclitaxel, carboplatin, and gemcitabine. However, unanticipated adverse events(finger ulcer)occurred. Thus, the chemotherapy was changed to paclitaxel, carboplatin, and etoposide. The patient is currently alive 4.2 years after the first chemotherapy, without evidence of recurrence. A 59-year-old man was diagnosed as having CUP with neuroendocrine carcinoma(NEC)and lymph node metastasis. He received chemotherapy with irinotecan and cisplatin. The lymph node metastases disappeared, but bone metastasis was found. The chemotherapy was changed to paclitaxel, carboplatin, and etoposide. The patient is currently alive 3.5 years after the first chemotherapy, without evidence of recurrence. We report 3rare cases of high-grade malignant CUP with complete pathological response, partial response, stable disease, and long-term survival after chemotherapy.