RESUMEN
The histological and molecular subtypes of breast cancer demand distinct therapeutic approaches. Invasive ductal carcinoma (IDC) is subtyped according to estrogen-receptor (ER), progesterone-receptor (PR), and HER2 status, among other markers. Desorption-electrospray-ionization-mass-spectrometry imaging (DESI-MSI) is an ambient-ionization MS technique that has been previously used to diagnose IDC. Aiming to investigate the robustness of ambient-ionization MS for IDC diagnosis and subtyping over diverse patient populations and interlaboratory use, we report a multicenter study using DESI-MSI to analyze samples from 103 patients independently analyzed in the United States and Brazil. The lipid profiles of IDC and normal breast tissues were consistent across different patient races and were unrelated to country of sample collection. Similar experimental parameters used in both laboratories yielded consistent mass-spectral data in mass-to-charge ratios ( m/ z) above 700, where complex lipids are observed. Statistical classifiers built using data acquired in the United States yielded 97.6% sensitivity, 96.7% specificity, and 97.6% accuracy for cancer diagnosis. Equivalent performance was observed for the intralaboratory validation set (99.2% accuracy) and, most remarkably, for the interlaboratory validation set independently acquired in Brazil (95.3% accuracy). Separate classification models built for ER and PR statuses as well as the status of their combined hormone receptor (HR) provided predictive accuracies (>89.0%), although low classification accuracies were achieved for HER2 status. Altogether, our multicenter study demonstrates that DESI-MSI is a robust and reproducible technology for rapid breast-cancer-tissue diagnosis and therefore is of value for clinical use.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Imagen Molecular , Espectrometría de Masa por Ionización de Electrospray , Neoplasias de la Mama/metabolismo , Femenino , Humanos , Grupos Raciales , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismoRESUMEN
BACKGROUND: The purpose of this study was to compare strength, body composition, and functional outcome measures following performance of the back squat, leg press, or a combination of the two exercises. METHODS: Subjects were pair-matched based on initial strength levels and then randomly assigned to 1 of 3 groups: a squat-only group (SQ) that solely performed squats for the lower body; a leg press-only group (LP) that solely performed leg presses for the lower body, or a combined squat and leg press group (SQ-LP) that performed both squats and leg presses for the lower body. All other RT variables were held constant. The study period lasted 10 weeks with subjects performing 2 lower body workouts per week comprising 6 sets per session at loads corresponding to 8-12 RM with 90- to 120-second rest intervals. RESULTS: Results showed that SQ had greater transfer to maximal squat strength compared to the leg press. Effect sizes favored SQ and SQ-LP versus LP with respect to countermovement jump while greater effect sizes for dynamic balance were noted for SQ-LP and LP compared to SQ, although no statistical differences were noted between conditions. CONCLUSIONS: These findings suggest that both free weights and machines can improve functional outcomes, and that the extent of transfer may be specific to the given task.