The hereditary cancer syndromes hereditary leiomyomatosis and renal cell cancer (HLRCC) and succinate dehydrogenase-related hereditary paraganglioma and pheochromocytoma (SDH PGL/PCC) are linked to germline loss-of-function mutations in genes encoding the Krebs cycle enzymes fumarate hydratase and succinate dehydrogenase, thus leading to elevated levels of fumarate and succinate, respectively. Here, we report that fumarate and succinate both suppress the homologous recombination (HR) DNA-repair pathway required for the resolution of DNA double-strand breaks (DSBs) and for the maintenance of genomic integrity, thus rendering tumor cells vulnerable to synthetic-lethal targeting with poly(ADP)-ribose polymerase (PARP) inhibitors. These results identify HLRCC and SDH PGL/PCC as familial DNA-repair deficiency syndromes, providing a mechanistic basis to explain their cancer predisposition and suggesting a potentially therapeutic approach for advanced HLRCC and SDH PGL/PCC, both of which are incurable when metastatic.

BackgroundWe reported previously that 18F-2-fluoro-2-deoxyglucose positron emission tomography/ computed tomography (FDG PET/CT) had potential for evaluating early response to treatment by tyrosine kinase inhibitors (TKIs) in advanced renal cell carcinoma (RCC). This time we investigated the relation of the early assessment by FDG PET/CT to long-term prognosis with an expanded number of patients and period of observation.MethodsPatients for whom TKI treatment for advanced RCC was planned were enrolled. FDG PET/CT was performed before TKI treatment and after one month of TKI treatment. The relations of the FDGPET/CT assessment to progression free survival (PFS) and overall survival (OS) were investigated.ResultsThirty-five patients were enrolled (sunitinib 19 cases, sorafenib 16 cases). The patients with RCC showing high SUVmax in pretreatment FDG PET/CT demonstrated short PFS (P =0.024, hazard ratio 1.137, 95% CI 1.017-1.271) and short OS (P =0.004, hazard ratio 1.210 95% CI 1.062-1.379). Thirty patients (sunitinib 16 cases, sorafenib 14 cases) were evaluated again after 1 month. The PFS of the patients whose SUVmax decreased<20% was shorter than that of the patients whose SUVmax decreased<20% (P = 0.027, hazard ratio 3.043, 95% CI 1.134-8.167). The PFS of patients whose tumor diameter sum increased was shorter than that of the patient with tumors whose diameter sum did not (P =0.006, hazard ratio 4.555, 95% CI 1.543-13.448).The patients were classified into three response groups: good responder (diameter sum did not increase, and SUVmax decreased ≥ 20%), intermediate responder (diameter sum did not increase, and SUVmax decreased<20%), and poor responder (diameter sum increased, or one or more new lesions appeared). The median PFS of good, intermediate, and poor responders were 458 ± 146 days, 131 ± 9 days, and 88 ± 26 days (good vs. intermediate P = 0.0366, intermediate vs. poor P = 0.0097, log-rank test). Additionally the mean OSs were 999 ± 70 days, 469 ± 34 days, and 374 ± 125 days, respectively (good vs. intermediate P = 0.0385, intermediate vs. poor P = 0.0305, log-rank test).ConclusionsThe evaluation of RCC response to TKI by tumor size and FDG uptake using FDG PET/CT after 1 month can predict PFS and OS.

BackgroundVarious molecular-targeting therapies have become available for the treatment of advanced renal cell carcinoma (RCC). Accurate prognostication is desirable for choosing the appropriate treatment for individual patients. 18F-2-fluoro-2-deoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) is a non-invasive tool for evaluating glucose accumulation, which can be an index of biological characteristics of cancer. We prospectively evaluated FDG PET/CT as a prognostic indicator in patients with advanced RCC.MethodsA total of 101 patients slated for different systematic therapies for advanced RCC were enrolled between 2008 and 2014. A total of 61 patients had recurrent RCC (58 metastatic and 3 regional) and 40 patients had stage IV RCC (36 metastatic and 4 locoregional). Sixteen patients had not undergone nephrectomy. Pre-treatment FDG PET/CT was performed, and the max SUVmax (the highest SUV measurement in each patient) was recorded. The max SUVmax was compared with different clinical risk factors as prognostic indicators. The median observation period was 18 months (range 1–70 months).ResultsThe max SUVmax of the 101 subjects ranged from undetectable to 23.0 (median 6.9). Patients with high max SUVmax had a poor prognosis. Multivariate analysis with standard risk factors revealed that max SUVmax was an independent predictor of survival (p < 0.001; hazard ratio 1.265; 95 % confidence interval 1.159–1.380). A cutoff of 8.8 for max SUVmax advocated in our previous report was highly significant (p < 0.0001). When we subclassified the max SUVmax values, the median overall survival of subjects with max SUVmax < 7.0 was 41.9 months. That of subjects with max SUVmax between 7.0 and 12.0 was 20.6 months. That of subjects with max SUVmax ≥ 12.0 was 4.2 months. The differences were statistically significant.ConclusionsPretreatment max SUVmax assessed by FDG PET/CT is a useful prognostic marker for patients with advanced RCC, providing helpful information for clinical decision making.

Objectives: To describe and to validate a novel patient-specific virtual-reality based simulator for laparoscopic surgery. Methods: Three surgeons carried out 13 preoperative simulations at Yokohama City University Hospital, Yokohama, Kanagawa, Japan, from 2011 to 2012. The procedures included seven nephrectomies, four partial nephrectomies and two pyeloplasties. We evaluated whether the anatomies reproduced by the simulator matched those encountered during the actual operations. Furthermore, the surgeons were asked to use visual analog scales (from 1 to 5; higher scores are better) to evaluate the anatomical integrity and utility of the simulations, and their intraoperative confidence during the subsequent surgical procedures. Results: The simulator reproduced the patients' anatomies almost perfectly. Only a few minor mistakes were identified. Regarding the surgeons' evaluations of the system, the mean scores for the anatomical integrity and utility of the simulations, and the surgeons' intraoperative confidence were 3.4, 4.2 and 4.1, respectively. In all 13 cases, the surgeons were able to carry out preoperative training with ease, and they stated that the simulator was useful for producing preoperative images. Conclusions: A patient-specific simulator for laparoscopic renal surgery has been successfully developed. This system correctly reproduces anatomical structures, and it seems to be a useful preoperative training tool.