Successful treatment of advanced pancreatic leiomyosarcoma treated with gemcitabine plus nab-paclitaxel: a case report and literature review.

Pancreatic leiomyosarcoma (PLMS) is an extremely rare tumor that accounts for 0.1% of pancreatic malignancies, and its chemotherapy has yet to be established. Generally, soft-tissue sarcoma chemotherapy is standard treatment with doxorubicin (DXR) alone. However, the effectiveness of gemcitabine (GEM) plus docetaxel (DOC) has been shown in uterine leiomyoma. In contrast, the GEM plus nab-paclitaxel (PTX) regimen has been established as first-line chemotherapy for unresectable pancreatic cancer. For this study, we selected the GEM plus nab-PTX regimen for patients with PLMS, achieving success in approximately 10 months. From a search on PubMed, we found only 12 cases of PLMS (including this case) that underwent chemotherapy. Our case is the first reported patient to have survived more than 2 years with chemotherapy alone. In a nude mouse model, the GEM plus DOC regimen was shown to significantly decrease tumor size when compared with DXR in leiomyosarcoma, and the GEM plus nab-PTX regimen was reported to significantly reduce necrosis when compared with DXR alone, GEM alone, DOC alone, nab-PTX alone and GEM plus DOC in soft-tissue sarcoma. GEM plus nab-PTX therapy might therefore be the first choice for soft-tissue sarcoma and leiomyosarcoma. This is the first reported case of PLMS treated with GEM plus nab-PTX. © The Japan Society of Clinical Oncology 2020.