Advanced Biosensors for Early Cancer Detection

Abstract

Early cancer detection -- identifying malignancies at stages I-II when five-year survival exceeds 90% for most solid tumours -- remains the single most impactful intervention in oncology. Yet conventional screening methods suffer from fundamental limitations: mammography misses 15-20% of breast cancers in dense tissue, low-dose CT for lung cancer produces 96% false positive rates at initial screening, and colonoscopy is invasive with 4-6% patient non-compliance for follow-up. Liquid biopsy biosensors that detect circulating tumour biomarkers -- cell-free DNA (cfDNA), circulating tumour cells (CTCs), exosomes, microRNAs, and protein biomarkers -- in peripheral blood offer a minimally invasive alternative. We present the Cancer Biosensor Assessment Framework (CBAF), evaluating five advanced biosensor platforms - electrochemical aptasensors, surface plasmon resonance (SPR) sensors, CRISPR-Cas-based diagnostic sensors, nanopore sequencing sensors, and lateral flow immunoassay (LFIA) point-of-care devices -- across four cancer types (non-small cell lung cancer, breast cancer, colorectal cancer, pancreatic ductal adenocarcinoma). Our Biosensor Diagnostic Performance Score (BDPS) measures analytical sensitivity, clinical specificity, limit of detection, time-to-result, and point-of-care deployability. CRISPR-Cas-based diagnostic sensors achieve the highest BDPS (0.926) through attomolar detection limits and built-in signal amplification, while lateral flow immunoassays achieve the highest point-of-care deployability (0.960) for resource-limited settings.