[Gas-Producing Splenic Abscess after Spleen Metastasis of Left Renal Cell Carcinoma Spleen Metastasis Successfully Treated with Sunitinib].

A 67-year-old man underwent open radical left nephrectomy for left renal cell carcinoma [pT4N0M1 (right lower lobe of lung)] and thoracoscopic partial right lung resection for lung metastasis. The patient subsequently developed a solitary lung metastasis at 10 months and then at 26 months postoperatively. He underwent partial lung resection on each occasion. During the 28 months postoperatively, he was found to have a 12 mm middle mediastinal lymph node metastasis and a 30 mm splenic metastasis, which gradually increased in size. Three months after discovery, sunitinib was initiated at 37.5 mg 2 weeks on/1 week off. Twelve days later, the patient presented with complaints of fever. A gas-producing splenic abscess was diagnosed and he was admitted on the same day. His condition improved with antibiotics and splenic drainage. On day 35 of hospitalization, he underwent laparoscopic splenectomy. The patient's postoperative clinical course was uneventful and he was discharged 7 days after the surgery.

Evaluation of in vivo responses of sorafenib therapy in a preclinical mouse model of PTEN-deficient of prostate cancer.

BACKGROUND: Despite recent advances in the treatment for advanced prostate cancer, outcomes remain poor. This lack of efficacy has prompted the development of alternative treatment strategies. In the present study we investigate the effects of the multikinase inhibitor sorafenib in a genetically engineered mouse model of prostate cancer and explore the rational combination with the mTOR inhibitor everolimus. METHODS: Conditional prostate specific PTEN-deficient knockout mice were utilized to determine the pharmacodynamic and chemopreventive effects of sorafenib. This mouse model was also used to examine the therapeutic efficacy of sorafenib alone or in combination with everolimus. Preclinical efficacy was assessed by comparing the reduction of tumor burden, proliferation, angiogenesis and the induction of apoptosis. Molecular responses were assessed by immunohistochemical, TUNEL and western blot assays. RESULTS: Pharmacodynamic analysis revealed that a single dose of sorafenib decreased activation of the PI3K/AKT/mTOR signaling axis at doses of 30-60 mg/kg, but activated JAK/STAT3 signaling. Levels of cleaved casapase-3 increased in a dose dependent manner. Chemoprevention studies showed that chronic sorafenib administration was capable of inhibiting tumor progression through the reduction of cancer cell proliferation, angiogenesis and the induction of apoptosis. In intervention models of established castration-naïve and castration-resistant prostate cancer, treatment with sorafenib provided modest but statistically insignificant reduction in tumor burden. However, sorafenib significantly inhibited cancer cell proliferation and MVD but had minimal effects on the induction of apoptosis. Interestingly, the administration of sorafenib increased the expression levels of the androgen receptor, p-GSK3ß and p-ERK1/2 in castration-resistant prostate cancers. In both intervention models, combination therapy demonstrated a clear tendency of enhanced antitumor effects over monotherapy. Notably, the treatment combination of sorafenib and everolimus overcame therapeutic escape from single agent therapy in castration-resistant prostate cancers. CONCLUSIONS: In summary, we provide insights into the molecular responses of sorafenib therapy in a clinically relevant model of prostate cancer and present preclinical evidence for the development of targeted treatment strategies based on the use of multikinase inhibitors in combination with mTOR inhibitors for the treatment of advanced prostate cancer.