Current trends in the management of bladder cancer

NMR-based metabolomic analysis of human bladder cancer

Bladder cancer (BC) is one of the most common cancers and has a high mortality rate. However, both metabolite variations and metabolic pathways related to the pathogenic process of BC remain to be addressed, such results might contribute to early detection of the disease. (1)H nuclear magnetic resonance (NMR)-based metabolomics was applied to identify differences of serum metabolic profiles among BC, calculi patients and healthy subjects. Serum metabolic profiles of BC patients are distinctly different from those of calculi and healthy subjects. Compared with those from healthy subjects, serum samples from BC patients show decreased levels of isoleucine/leucine, tyrosine, lactate, glycine, citrate, as well as increased levels of lipids and glucose. The results reveal disturbed metabolic pathways of aromatic amino acids, glycolysis and citrate cycle, as well as lipogenesis metabolism in BC patients. Our work will be of potential benefit to understanding the pathogenic process of BC and will offer valuable information for noninvasive diagnosis of the disease.

Efficiency of study designs in diagnostic randomized clinical trials

From the patients' management perspective, a good diagnostic test should contribute to both reflecting the true disease status and improving clinical outcomes. The diagnostic randomized clinical trial is designed to combine both diagnostic tests and therapeutic interventions. Evaluation of diagnostic tests is carried out with therapeutic outcomes as the primary endpoint rather than test accuracy. We lay out the probability framework for evaluating such trials. We compare two commonly referred designs-the two-arm design and the paired design-in a formal statistical hypothesis testing setup and identify the causal connection between the two tests. The paired design is shown to be more efficient than the two-arm design. The efficiency gains vary depending on the discordant rates of test results. We derive sample size formulas for both binary and continuous endpoints. We derive estimation of important quantities under the paired design and also conduct simulation studies to verify the theoretical results. We illustrate the method with an example of designing a randomized study on preoperative staging of bladder cancer.

Modified full-field optical coherence tomography: A novel tool for rapid histology of tissues

Background:

Here, we report the first use of a commercial prototype of full-field optical coherence tomography called Light-CT™. Based on the principle of white light interferometry, Light-CT™ generates quick high-resolution three-dimensional tomographic images from unprocessed tissues. Its advantage over the current intra-surgical diagnostic standard, i.e. frozen section analysis, lies in the absence of freezing artifacts, which allows real-time diagnostic impressions, and/or for the tissues to be triaged for subsequent conventional histopathology.

Materials and Methods:

In this study, we recapitulate known normal histology in nine formalin fixed ex vivo rat organs (skin, heart, lung, liver, stomach, kidney, prostate, urinary bladder, and testis). Large surface and virtually sectioned stacks of images at varying depths were acquired by a pair of 10×/0.3 numerical aperture water immersion objectives, processed and visualized in real time.

Results:

Normal histology of the following organs was recapitulated by identifying various tissue microstructures. Skin: epidermis, dermal-epidermal junction and hair follicles with surrounding sebaceous glands in the dermis. Stomach: mucosa with surface pits, submucosa, muscularis propria and serosa. Liver: hepatocytes separated by sinusoidal spaces, central veins and portal triad. Kidney: convoluted tubules, medullary rays (straight tubules) and collecting ducts. Prostate: acini and fibro-muscular stroma. Lung: bronchi, bronchioles, alveolar ducts, alveoli and pleura. Urinary bladder: urothelium, lamina propria, muscularis propria, and serosa. Testis: seminiferous tubules with intra-tubular sperms.

Conclusion:

Light-CT™ is a powerful imaging tool to perform fast histology on fresh and fixed tissues, without introducing artifacts. Its compact size, ease of handling, fast image acquisition and safe incident light levels makes it well-suited for various intra-operative and intra-procedural triaging and decision making applications.