Liquid biopsy for cancer diagnosis using vibrational spectroscopy: systematic review

Background Vibrational spectroscopy (VS) is a minimally invasive tool for analysing biological material to detect disease. This study aimed to review its application to human blood for cancer diagnosis. Methods A systematic review was undertaken using a keyword electronic database search (MEDLINE, Embase, PubMed, TRIP and Cochrane Library), with all original English‐language manuscripts examining the use of vibrational spectral analysis of human blood for cancer detection. Studies involving fewer than 75 patients in the cancer or control group, animal studies, or where the primary analyte was not blood were excluded. Results From 1446 results, six studies (published in 2010–2018) examining brain, bladder, oral, breast, oesophageal and hepatic cancer met the criteria for inclusion, with a total population of 2392 (1316 cancer, 1076 control; 1476 men, 916 women). For cancer detection, reported mean sensitivities in each included study ranged from 79·3 to 98 per cent, with specificities of 82·8–95 per cent and accuracies between 81·1 and 97·1 per cent. Heterogeneity in reporting strategies, methods and outcome measures made meta‐analysis inappropriate. Conclusion VS shows high potential for cancer diagnosis, but until there is agreement on uniform standard reporting methods and studies with adequate sample size for valid classification models have been performed, its value in clinical practice will remain uncertain. Antecedentes la espectroscopia vibracional (vibrational spectroscopy, VS) es un dispositivo mínimamente invasivo para analizar material biológico y detectar enfermedad. Este estudio se propuso revisar su aplicación en la sangre humana para el diagnóstico de cáncer. Métodos Se llevó a cabo una revisión sistemática utilizando una búsqueda con palabras claves en bases de datos electrónicas (MEDLINE, EMBASE, PubMed, TRIP, Cochrane Library), de todos los manuscritos originales publicados en inglés que examinaban la utilización del análisis espectral vibracional de la sangre humana para la detección del cáncer. Se excluyeron estudios que incluían menos de 75 pacientes en los grupos cáncer/control, estudios en animales o cuando la muestra principal no fuera la sangre. Resultados De los 1.446 resultados, 6 estudios publicados en 2010‐2018, y que examinaban cánceres del cerebro, vejiga, oral, mama, esófago e hígado cumplieron los criterios de inclusión, con una población total de 2.506 casos (1.316 cánceres, 1.076 controles; 1.476 varones, 915 mujeres). Pa