Biology of BCG response in non-muscle invasive bladder cancer - 2021 IBCN Updates Part III.

Bacillus Calmette-Guerin (BCG) remains the only FDA-approved first-line therapy in patients with high-risk non-muscle invasive bladder cancer. Recurrences, even after adequate BCG therapy, are common and the efficacy of second-line therapies remains modest. Therefore, early identification of patients likely to recur and treatment after recurrence remain critical unmet needs in the clinical care of bladder cancer patients. To address these deficits, a better understanding of the mechanisms of resistance to BCG-therapy is needed. The virtual update of the International Bladder Cancer Network (IBCN) on the biology of response to BCG focused on potential mechanisms and markers of resistance to intravesical BCG therapy. The insights from this meeting will be highlighted and put into context of previously reported mechanisms of resistance to BCG in this review.

Pursuing Quality in the Application of Bladder Cancer Quality of Life Research.

Patient-reported outcomes (PRO), including health-related quality of life (HRQOL) measures, represent important means for evaluating patients' health outcomes and for guiding health care decisions made by patients, practitioners, investigators, and policy makers. In spite of the large number of studies examining HRQOL in patients with bladder cancer, very few review articles investigated this topic. Because these review studies report mixed results, incorporating bladder cancer HRQOL measures into standard urological practice is not a viable option. In this non-systematic review of the literature and commentary we note some general concerns regarding PRO research, but our primary focus is on the HRQOL methodology within the context of two types of bladder cancer: muscle invasive and non-muscle invasive bladder cancer. Considering bladder cancer HRQOL as the interaction of four areas of the assessment process (i.e., what model of HRQOL to choose, what instruments are available to fit the choice, how interpretation of the resulting data fits the model, and how to derive some utility from the chosen model) and the two types of disease (i.e., muscle invasive and non-muscle invasive) may move us toward a better understanding of bladder cancer HRQOL. Establishing a useful model of perceived general health or specific symptoms is the first and most important step in developing the responsive bladder cancer HRQOL measures necessitated by clinical settings.

Outcomes in patients undergoing nephrectomy for renal cancer on chronic anticoagulation therapy.

AIMS: To report our experience on surgical resection of renal tumors for patients with a history of chronic anticoagulation (ACT) or aspirin use. METHODS: We performed a retrospective analysis of 2473 patients who underwent surgery for renal tumors between 2005 and 2012. Prior to surgery, 172 were on chronic ACT and 695 on aspirin. Multivariable linear and logistic regression models were used to compare transfusion and overall complication rates between patients undergoing renal surgery who were on therapy to patients who were on aspirin and to patients with no therapy. RESULTS: Compared to no therapy and aspirin patients those on ACT were older (57.3 (IQR 48.4-66.10) vs 63.9, (IQR 57.3-71.5) vs 68.4, (IQR 60.4-73.5); p < 0.001), with a higher percentage having an ASA score of 3 or 4 (42.4 vs 57.9 vs 82.6%; p < 0.001), respectively. ACT patients had a higher 30-day transfusion rate, 22.7% vs 7.6% vs 6.9%, and 90-day complication rate, 17.4% vs 7.2% vs 7.3%, both p < 0.001. The median length of stay differed statistically between groups (p < 0.001), with a modest longer stay in the anticoagulation group (OR 1.11 SE 0.26; p < 0.001). Transfusion and complication rates for patients on therapy undergoing minimally invasive surgery vs open surgery were not statistically different. CONCLUSIONS: Patients on chronic ACT had higher transfusion and overall complication rates compared to patients on no treatment or on chronic aspirin. These findings did not correlate to clinical differences in length of stay or grade 3-5 complications.

Radical cystectomy and orthotopic urinary reconstruction in patients with bladder cancer after renal transplantation: clinical outcomes and description of technique.

OBJECTIVES: Radical cystectomy (RC) with pelvic lymph node dissection and urinary diversion is the standard treatment for muscle-invasive bladder cancer. In the setting of prior renal transplantation, surgical treatment remains the mainstay but is technically challenging. We report our patient outcomes in this unique population with a description of the technique. METHODS: We identified five patients with a history of renal transplantation who underwent RC and orthotopic urinary diversion. Preoperative clinical and demographic features were compiled and disease-specific and functional outcomes were assessed. Intraoperative technical challenges and maneuvers for avoiding complications are highlighted. RESULTS: Four patients were male and one was female, with a median age of 64 years. Gross hematuria was the most common sign at presentation. Clinical staging was T2, T2 with carcinoma in situ (CIS), high-grade (HG) Ta with CIS, T2 with squamous differentiation, and HG T1, and pathologic tumor stage was pTisN1, pT3N0, pTisN0, pT3N0, and pT0N0, respectively. One patient received a Studer-type diversion and four underwent Hautmann diversion. Median follow-up after cystectomy was 12.9 months. Graft ureteral identification was aided by the use of intravenous dye in all patients. Ipsilateral pelvic lymph node dissection was not possible in any patient. All patients are alive at follow-up, with two experiencing recurrence at 7.2 months and 66.8 months. No patient experienced a significant decrease in estimated creatinine clearance postoperatively. Postoperative daytime control was reported by all patients whereas two noted complete nighttime control. CONCLUSIONS: RC with orthotopic diversion is a technically demanding procedure in patients with a history renal transplantation. Meticulous technique and careful attention to the altered anatomy are required for successful outcomes.

Sensitivity of human immunodeficiency virus type 1 to fusion inhibitors targeted to the gp41 first heptad repeat involves distinct regions of gp41 and is consistently modulated by gp120 interactions with the coreceptor.

T-20 is a synthetic peptide that corresponds to 36 amino acids within the C-terminal heptad repeat region (HR2) of human immunodeficiency virus type 1 (HIV-1) gp41. T-20 has been shown to potently inhibit viral replication of HIV-1 both in vitro and in vivo and is currently being evaluated in a Phase III clinical trial. T-649 is an inhibitory peptide that also corresponds to 36 amino acids within HR2. This sequence overlaps the T-20 sequence but is shifted 10 residues toward the N terminus of gp41. Both inhibitors are thought to exert their antiviral activity by interfering with the conformational changes that occur within gp41 to promote membrane fusion following gp120 interactions with CD4 and coreceptor molecules. We have shown previously that coreceptor specificity defined by the V3 loop of gp120 modulates sensitivity to T-20 and that a critical region within the N-terminal heptad repeat (HR1) of gp41 is the major determinant of sensitivity (C. A. Derdeyn et al., J. Virol. 74:8358-8367, 2000). This report shows that (i) regions within gp41 distinct from those associated with T-20 sensitivity govern the baseline sensitivity to T-649 and (ii) T-649 sensitivity of chimeric viruses that contain sequences derived from CXCR4- and CCR5-specific envelopes is also modulated by coreceptor specificity. Moreover, the pattern of sensitivity of CCR5-specific chimeras with only minor differences in their V3 loop was consistent for both inhibitors, suggesting that the individual affinity for coreceptor may influence accessibility of these inhibitors to their target sequence. Finally, an analysis of the sensitivity of 55 primary, inhibitor-naive HIV-1 isolates found that higher concentrations of T-20 (P < 0.001) and T-649 (P = 0.016) were required to inhibit CCR5-specific viruses compared to viruses that utilize CXCR4. The results presented here implicate gp120-coreceptor interactions in driving the complex conformational changes that occur in gp41 to promote fusion and entry and suggest that sensitivity to different HR1-directed fusion inhibitors is governed by distinct regions of gp41 but is consistently modulated by coreceptor specificity.

Sensitivity of human immunodeficiency virus type 1 to the fusion inhibitor T-20 is modulated by coreceptor specificity defined by the V3 loop of gp120.

T-20 is a synthetic peptide that potently inhibits replication of human immunodeficiency virus type 1 by interfering with the transition of the transmembrane protein, gp41, to a fusion active state following interactions of the surface glycoprotein, gp120, with CD4 and coreceptor molecules displayed on the target cell surface. Although T-20 is postulated to interact with an N-terminal heptad repeat within gp41 in a trans-dominant manner, we show here that sensitivity to T-20 is strongly influenced by coreceptor specificity. When 14 T-20-naive primary isolates were analyzed for sensitivity to T-20, the mean 50% inhibitory concentration (IC(50)) for isolates that utilize CCR5 for entry (R5 viruses) was 0.8 log(10) higher than the mean IC(50) for CXCR4 (X4) isolates (P = 0. 0055). Using NL4.3-based envelope chimeras that contain combinations of envelope sequences derived from R5 and X4 viruses, we found that determinants of coreceptor specificity contained within the gp120 V3 loop modulate this sensitivity to T-20. The IC(50) for all chimeric envelope viruses containing R5 V3 sequences was 0.6 to 0.8 log(10) higher than that for viruses containing X4 V3 sequences. In addition, we confirmed that the N-terminal heptad repeat of gp41 determines the baseline sensitivity to T-20 and that the IC(50) for viruses containing GIV at amino acid residues 36 to 38 was 1.0 log(10) lower than the IC(50) for viruses containing a G-to-D substitution. The results of this study show that gp120-coreceptor interactions and the gp41 N-terminal heptad repeat independently contribute to sensitivity to T-20. These results have important implications for the therapeutic uses of T-20 as well as for unraveling the complex mechanisms of virus fusion and entry.

HPLC-mass spectrometry analysis of isoflavones.

The current interest in the role of dietary isoflavonoids, particularly the soy isoflavone genistein, in lowering the risk of several chronic diseases, has led to the need for rapid, sensitive and precise assays for isoflavones and their metabolites in food matrices and in various physiological fluids and tissues. HPLC has the advantage over GC-based methods in that all the conjugated and unconjugated isoflavonoids and their metabolites can be separated and analyzed without the need for derivatization. An important advance in mass spectrometry has been the introduction of effective interfaces between the HPLC and the mass spectrometer, namely the electrospray ionization (ESI) and the heated nebulizer-atmospheric pressure chemical ionization (HN-APCI) interfaces. Because of the isoflavonoid concentrations in fluids such as bile or urine, preliminary extraction, so essential for GC-MS and many other analytical methods, is not necessary. This immediately overcomes the thorny issue of finding an effective solid-phase extraction procedure. Using reversed-phase HPLC-ESI-MS, it is possible to obtain a mass/intensity map of all isoflavonoid metabolites in a single 20 min analysis. Analysis of isoflavonoid conjugates in serum/plasma samples requires initial extraction, but the conjugates can be measured intact either by capillary reversed-phase HPLC-ESI-MS or on regular reversed-phase columns by HPLC-HN-APCI-MS. In both cases, specificity is obtained by causing the parent isoflavonoid molecular ions to undergo collision-induced dissociation to form specific daughter ions in a triple quadrupole MS instrument. When it is only necessary to measure the total isoflavonoids and their metabolites in blood, hydrolysis can be performed directly in serum/plasma samples and isoflavonoids recovered by ether or ethyl acetate solvent extraction. The isoflavone aglucones can be analyzed by HPLC-MS under isocratic solvent conditions, thereby drastically shortening analysis time and opening up prospects for automation. Therefore, HPLC-MS is a technique that is broadly applicable to the major issues in phytoestrogen research.

Intestinal uptake and biliary excretion of the isoflavone genistein in rats.

The intestinal absorption, biliary excretion and metabolism of genistein, a potent and specific protein tyrosine kinase inhibitor that occurs naturally in soy foods, was examined in anesthetized, adult female rats fitted with indwelling biliary cannulas. 4-14C-Genistein, when infused into the duodenum, was rapidly absorbed from the intestine, taken up by the liver and excreted into the bile as its 7-O-beta-glucuronide conjugate. Cumulative recovery of 14C-radioactivity in the bile over a 4-h period was 70-75% of the dose. When genistein was infused into the portal vein, it was also taken up efficiently by the liver, conjugated with glucuronic acid and transported into bile. However, portal blood collected after duodenal infusions of genistein contained mostly genistein 7-O-beta-glucuronide, suggesting that in vivo glucuronidation occurred in the intestinal wall rather than the liver. This was confirmed using everted intestinal sac preparations. Reinfusion of genistein 7-O-beta-glucuronide into the duodenum or into the mid small intestine resulted in its reappearance in the bile, albeit more slowly than when genistein was infused. Over a 4-h collection period, the cumulative recovery of 14C-radioactivity in bile was 27 and 70-75% of the administered dose for duodenal and ileal infusions, respectively. These data indicate that genistein is highly bioavailable in rats and because of its enterohepatic circulation may accumulate within the gastrointestinal tract.

Soy isoflavonoids and cancer prevention. Underlying biochemical and pharmacological issues.

The isoflavonoids in soy, genistein and daidzein, have been proposed to contribute an important part of the anti-cancer effect of soy. Although there have been many interesting studies on the effects of isoflavones on biochemical targets in tissue culture experiments, in most cases the concentrations used by investigators have exceeded 10 microM. However, based on simple pharmacokinetic calculations involving daily intake of isoflavones, absorption from the gut, distribution to peripheral tissues, and excretion, it is unlikely that blood isoflavone concentrations even in high soy consumers could be greater than 1-5 microM. Experiments designed to evaluate these pharmacological principles were carried out in anesthetized rats with indwelling biliary catheters and in human volunteers consuming soy beverages. The data from these experiments indicate that genistein is efficiently absorbed from the gut, taken up by the liver and excreted in the bile as its 7-O-beta-glucuronide. Re-infused genistein 7-O-beta-glucuronide was also well absorbed from the gut, although this occurred in the distal small intestine. In human subjects fed a soy beverage for a period of two weeks, plasma levels of genistein and daidzein, determined by HPLC-mass spectrometry, ranged from 0.55-0.86 microM, mostly as glucuronide and sulfate conjugates. In summary, genistein is well absorbed from the small intestine and undergoes an enterohepatic circulation. Although the plasma genistein levels achievable with soy food feeding are unlikely to be sufficient to inhibit the growth of mature, established breast cancer cells by chemotherapeutic-like mechanisms, these levels are sufficient to regulate the proliferation of epithelial cells in the breast and thereby may cause a chemopreventive effect.