Wait-and-scan management in sporadic Koos grade 4 vestibular schwannomas: A longitudinal volumetric study.

Background: Volumetric natural history studies specifically on large vestibular schwannomas (VSs), commonly classified as Koos grade 4, are lacking. The aim of the current study is to present the volumetric tumor evolution in sporadic Koos grade 4 VSs and possible predictors for tumor growth. Methods: Volumetric tumor measurements and tumor evolution patterns from serial MRI studies were analyzed from selected consecutive patients with Koos grade 4 VS undergoing initial wait-and-scan management between January 2001 and July 2020. The significant volumetric threshold was defined as a change in volume of ≥10%. Results: Among 215 tumors with a median size (IQR) of 2.7 cm3 (1.8-4.2), 147 tumors (68%) demonstrated growth and 75 tumors (35%) demonstrated shrinkage during follow-up. Growth-free survival rates (95% CI) at 1, 2, 5, and 10 years were 55% (48-61), 36% (29-42), 29% (23-36), and 28% (21-34), respectively and did not significantly differ in tumors> 20 mm (Chi-square = .40; P-value = .53). Four tumor evolution patterns (% of total) were observed: continued growth (60); initial growth then shrinkage (7); continued shrinkage (27); and stability (5). Good hearing (adjusted HR 2.21, 95% CI 1.48-3.30; P < .001) and peritumoral edema (adjusted HR 2.22, 95% CI 1.18-4.13; P = .01) at diagnosis were significantly associated with an increased likelihood of growth. Conclusions: Koos grade 4 VSs show a wide variety in size and growth. Due to variable growth patterns, an initial wait-and-scan strategy with short scan intervals may be an acceptable option in selected tumors, if no significant clinical symptoms of mass effect that warrant treatment are present.

Plasma Epstein-Barr Virus DNA and Risk of Future Nasopharyngeal Cancer.

BACKGROUND: We previously conducted a prospective study to show that nasopharyngeal cancer (NPC) screening with circulating Epstein­Barr virus (EBV) DNA analysis can improve survival. However, the long-term significance of positive results in individuals without cancer was unclear. METHODS: We conducted a second-round screening at a median of 43 months after the initial screening. Participants with detectable plasma EBV DNA were retested in 4 weeks, and those with persistently positive results were investigated with nasal endoscopy and magnetic resonance imaging. RESULTS: Of the 20,174 volunteers who participated in the first-round screening, 17,838 (88.6%) were rescreened. Among them, 423 (2.37%) had persistently detectable plasma EBV DNA. Twenty-four patients were identified as having NPC. A significantly higher proportion of patients had stage I/II cancer than in a historical cohort (67% vs. 20%; chi-square test, P<0.001), and they had superior 3-year progression-free survival (100% vs. 78.8%). Compared with participants with undetectable plasma EBV DNA in the first round of screening, participants with transiently and persistently positive results in the first round were more likely to have a cancer identified in the second round, with relative risks of 4.4 (95% confidence interval, 1.3 to 15.0) and 16.8 (95% confidence interval, 5.7 to 49.6), respectively. CONCLUSIONS: Individuals with detectable plasma EBV DNA but without an immediately identifiable NPC were more likely to have the cancer identified in another round of screening performed 3 to 5 years later. (Funded by Kadoorie Charitable Foundation and others; ClinicalTrials.gov number, NCT02063399.)

Bile acids. LXXXI. Synthesis and structural assignment of E/Z isomers of substituted methyl hydroxy-5 beta-cholest-24-en-26-oates.

Syntheses of the E and Z isomers of methyl 3 alpha-,3 alpha,7 alpha-,3 alpha,12 alpha-, and 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-24-en-26-oates are reported. Mass spectral studies show fragmentation patterns in support of assignment as the E or Z isomers, especially in differences in loss of the side chain. Chromatographic procedures, primarily gas chromatography and high-performance liquid chromatography, support these assignments. The E isomer predominates in either of two methods of synthesis.

Bile acids. LXXVI. Analyses of bile acids and sterols by high-performance liquid chromatography with a microbore column.

The mobilities of several free and conjugated 5 beta-bile acids, cholesterol and analogues, and alpha, beta-unsaturated sterols and steroidal acids have been investigated with a microbore reversed-phase high-performance liquid chromatographic column (50 cm X 1 mm I.D., 12% C18) with appropriate solvent mixtures at flow-rates of 50-100 microliter/min and a UV monitor set at 193, 198, 212, or 243 nm. With a solvent mixture of 2-propanol-10 mM phosphate buffer, pH 7.0 (160:340) bile acids or their conjugates were separated in a manner similar to those by microBondapak columns (10% C18). The lower detection limit of the conjugates was 20 pmoles with the UV detector set at 193 nm, whereas the lower limit for alpha, beta-unsaturated keto sterols or steroidal acids was 5 pmoles at 243 nm. The detection limit for cholesterol with the UV monitor at 198 nm was 10 pmoles. Contributions of substituent groups of sterols to their time of elution (capacity factor) were calculated for several substituted 4-cholesten-3-ones.

Bile acids. LXXII. High-performance liquid chromatographic analysis of bile acid coenzyme A derivatives.

The mobilities of coenzyme A and coenzyme A derivatives of cholate, chenodeoxycholate, deoxycholate, lithocholate, and their 5 alpha analogs were studied in reversed-phase high-performance liquid chromatography. With a C18 Radial-PAK A cartridge (10-micron particles) and a solvent mixture of 2-propanol/10 mM phosphate buffer (pH 7.0, 140:360), separation of the chenodeoxycholyl and deoxycholyl coenzyme A derivatives was not observed. An increase in ionic strength of the buffer to 50 mM afforded separation, which was markedly augmented with a C18 Radial-PAK A cartridge with 5-micron particles. Lowering the pH of the buffer to 5.5 did not materially change the separations regardless of the ionic strength. Quantitation was carried out to a lower level of 8.5 X 10(-12) mol.