Assessment of Frailty Can Guide Decision Making for Utilization of Sentinel Lymph Node Biopsy in Patients with Thick Melanoma.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is often omitted in selected patients with advanced primary melanoma, although the justification/criteria for omission have been debated. OBJECTIVE: We sought to determine whether assessment of frailty could serve as an objective marker to guide selection for SLNB in patients with advanced primary melanoma. METHODS: Patients presenting with clinical stage IIC (ulcerated, > 4 mm Breslow thickness) cutaneous melanoma from January 1999 through June 2019 were included. Frailty was assessed using the Memorial Sloan Kettering Frailty Index (MSK FI), a composite score of functional status and medical comorbidities. Five-year melanoma-specific survival (MSS) and overall survival (OS) were estimated using Cox regression, and predictors of OS were identified using competing risk models. RESULTS: MSS did not differ between patients who did (n = 451) or did not undergo SLNB (n = 179) [63.2% vs. 65.0%, p = 0.14]; however, omission of SLNB was associated with decreased 5-year OS (29% vs. 44%, p < 0.001). In a multivariable competing risk model, selection for SLNB omission was an independent predictor of death from non-melanoma causes (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.3, p < 0.001). After incorporation of the MSK FI score into the multivariable model in this subset, MSK FI (HR 2.4, 95% CI 1.5-4.1, p < 0.001), but not SLNB omission, was an independent predictor of poorer OS. CONCLUSION: We observed worse OS in patients with thick melanoma selected not to undergo SLNB, which was attributed to death due to non-melanoma causes. Formal assessment of frailty may provide an objective prognostic measure to guide selective use of SLNB in these patients.

Utilizing the iron tolerance potential of Bacillus species for biogenic synthesis of magnetite with visible light active catalytic activity.

Recently, nanomaterial mediated degradation of water polluting industrial pollutant and dyes has become a topic of great interest. This study demonstrates enrichment, isolation, screening and molecular identification of iron tolerant Bacillus species for biosynthesis of iron oxide magnetic nanoparticles (IOMNPs). Synthesis parameters such as 5 mM FeCl3, 7 days of static incubation at 37 °C and slightly alkaline pH range of 7-7.5 were the most optimum conditions. The spectroscopic and imaging studies demonstrated inverse spinel face-centered cubic structure of magnetite with average size of 81.3 nm, polydispersity of 0.343 and zeta potential of -42.49 mV. The specific saturation magnetization value and coercivity Hc of hysteresis loop of 28.1 emu/g and 5.8 Oe respectively confirmed the super-paramagnetic nature of IOMNPs. The comparison of phtotocatalytic activities under UV and visible light irradiation for degrdation of methyl violet, methylene blue, and rhodamine-B indicated that IOMNPs were visible light active photocatalysts. The study of effects of various reaction parameters indicated that catalyst loadings of 500-600 µg/mL, pH 7 and 20 µg/mL initial dye concetration were optimum conditions and reactions at these parameters were also observed to follow pseudo first order kinetics. This study successfully demonstrated the use of iron tolerant bacterium for visible light active, photocatalyst synthesis.