Myopodin methylation is a prognostic biomarker and predicts antiangiogenic response in advanced kidney cancer

Myopodin is a cytoskeleton protein that shuttles to the nucleus depending on the cellular differentiation and stress. It has shown tumor suppressor functions. Myopodin methylation status was useful for staging bladder and colon tumors and predicting clinical outcome. To our knowledge, myopodin has not been tested in kidney cancer to date. The purpose of this study was to evaluate whether myopodin methylation status could be clinically useful in renal cancer (1) as a prognostic biomarker and 2) as a predictive factor of response to antiangiogenic therapy in patients with metastatic disease. Methylation-specific polymerase chain reactions (MS-PCR) were used to evaluate myopodin methylation in 88 kidney tumors. These belonged to patients with localized disease and no evidence of disease during follow-up (n = 25) (group 1), and 63 patients under antiangiogenic therapy (sunitinib, sorafenib, pazopanib, and temsirolimus), from which group 2 had non-metastatic disease at diagnosis (n = 32), and group 3 showed metastatic disease at diagnosis (n = 31). Univariate and multivariate Cox analyses were utilized to assess outcome and response to antiangiogenic agents taking progression, disease-specific survival, and overall survival as clinical endpoints. Myopodin was methylated in 50 out of the 88 kidney tumors (56.8 %). Among the 88 cases analyzed, 10 of them recurred (11.4 %), 51 progressed (57.9 %), and 40 died of disease (45.4 %). Myopodin methylation status correlated to MSKCC Risk score (p = 0.050) and the presence of distant metastasis (p = 0.039). Taking all patients, an unmethylated myopodin identified patients with shorter progression-free survival, disease-specific survival, and overall survival. Using also in univariate and multivariate models, an unmethylated myopodin predicted response to antiangiogenic therapy (groups 2 and 3) using progression-free survival, disease-specific, and overall survival as clinical endpoints. Myopodin was revealed hypermethylated in kidney cancer. Myopodin methylation status identified which patients showed a more aggressive clinical behavior and predicted antiangiogenic response. These observations support the clinical utility of an unmethylated myopodin as a prognostic and predictive biomarker in kidney cancer.

Evaluation of the impact of three-dimensional vision on laparoscopic performance

INTRODUCTION

Recent technological advancements have led to the introduction of new three-dimensional (3D) cameras in laparoscopic surgery. The 3D view has been touted as useful during robotic surgery, however, there has been limited investigation into the utility of 3D in laparoscopy.

MATERIALS AND METHODS

We performed a prospective, randomized crossover trial comparing a 0° 3D camera with a conventional 0° two-dimensional (2D) camera using a high definition monitor (Karl Storz, Tuttlingen, Germany). All participants completed six standardized basic skills tasks. Quality testing scores were measured by the number of drops, grasping attempts, and precision of needle entry and exiting. Additionally, resolution, color distribution, depth of field and distortion were measured using optical test targets.

RESULTS

In this pilot study, we evaluated 10 medical students, 7 residents, and 7 expert surgeons. There was a significant difference in the performance in all the six skill tasks, for the three levels of surgical expertise and training levels in 2D vs 3D except for the cut the line quality score and the peg transfer quality score. Adjusting for the training level, 3D camera image results were superior for the number of rings left (p=0.041), ring transfer quality score (p=0.046), thread the rings (no. of rings) (p=0.0004), and thread the rings quality score (p=0.0002). The 3D camera image was also superior for knot tying (quality score) (p=0.004), peg transfer (time in seconds) (p=0.047), peg transfer pegs left (p=0.012), and for peg transfer quality score (p=0.001). The 3D camera system showed significantly less distortion (p=0.0008), a higher depth of field (p=0.0004) compared with the 2D camera system.

CONCLUSION

3D laparoscopic camera equipment results in a significant improvement in depth perception, spatial location, and precision of surgical performance compared with the conventional 2D camera equipment. With this improved quality of vision, even expert laparoscopic surgeons may benefit from 3D imaging.