Is Systemic Anticancer Therapy Associated With Higher Rates of Malignant Pleural Effusion Control in People With Pharmacologically Sensitive Tumors?: A Retrospective Analysis of Prospectively Collected Data.

BACKGROUND: Malignant pleural effusions (MPEs) often cause symptoms, and guidelines recommend early definitive intervention. However, observational data suggest that systemic anticancer treatment (SACT) may control MPE caused by certain pharmacologically sensitive tumors. RESEARCH QUESTION: Is SACT associated with higher rates of MPE resolution in people with pharmacologically sensitive tumors? STUDY DESIGN AND METHODS: This was a retrospective analysis of prospectively collected data from an observational cohort study of people diagnosed with MPE from lung, breast, ovarian, and hematologic malignancy between May 11, 2008, and August 6, 2017. MPE resolution (defined as radiologic resolution with removal of drain or catheter and cessation of interventions) was compared in pharmacologically sensitive (high-grade lymphoma, small cell or target-mutation-positive lung cancer, and hormone-receptor-positive breast or ovarian cancer) and nonsensitive (remainder of cohort) tumors, with and without SACT. Secondary outcomes included time to resolution, 3-month resolution rates, and total pleural interventions. RESULTS: Of 280 patients, 127 had sensitive and 153 had nonsensitive tumors. One hundred seventy-one received SACT, and 109 did not. More patients with sensitive tumors achieved MPE resolution than those with nonsensitive tumors (53/127 [41.7%] vs 42/153 [27.5%]; P = .01), and this occurred predominantly after receipt of SACT. However, hematologic malignancies were overrepresented in the sensitive group, with high rates of SACT use and MPE resolution. After adjustment for this and other confounders, no relationship was found among pharmacologic sensitivity, SACT, and MPE resolution (adjusted OR, 1.4; 95% CI, 0.5-4.1). The strongest predictor of MPE resolution was administration of chemical pleurodesis (adjusted OR, 6.2; 95% CI, 3.3-11.7). In sensitive tumors, MPE resolution occurred without chemical pleurodesis in 14 of 52 patients (26.9%; 95% CI, 15.6%-41.1%) after SACT and in 5 of 22 patients (22.7%; 95% CI, 8.2%-47.2%) without SACT. INTERPRETATION: In this observational study, SACT was not associated independently on MPE resolution in pharmacologically sensitive tumors. Randomized trials are required, but with current data, patients with symptomatic MPE should receive early definitive pleural intervention regardless of underlying tumor or intended treatment.

Evaluation of environmental scanning electron microscopy for analysis of Proteus mirabilis crystalline biofilms in situ on urinary catheters.

Proteus mirabilis is a common cause of catheter-associated urinary tract infections and frequently leads to blockage of catheters due to crystalline biofilm formation. Scanning electron microscopy (SEM) has proven to be a valuable tool in the study of these unusual biofilms, but entails laborious sample preparation that can introduce artefacts, undermining the investigation of biofilm development. In contrast, environmental scanning electron microscopy (ESEM) permits imaging of unprocessed, fully hydrated samples, which may provide much insight into the development of P. mirabilis biofilms. Here, we evaluate the utility of ESEM for the study of P. mirabilis crystalline biofilms in situ, on urinary catheters. In doing so, we compare this to commonly used conventional SEM approaches for sample preparation and imaging. Overall, ESEM provided excellent resolution of biofilms formed on urinary catheters and revealed structures not observed in standard SEM imaging or previously described in other studies of these biofilms. In addition, we show that energy-dispersive X-ray spectroscopy (EDS) may be employed in conjunction with ESEM to provide information regarding the elemental composition of crystalline structures and demonstrate the potential for ESEM in combination with EDS to constitute a useful tool in exploring the mechanisms underpinning crystalline biofilm formation.