<p>This work introduces a biosensor using a dielectric modulated inverted C-shaped junction tunnel field-effect transistor (DM-ICJ-TFET) to early diagnosis of breast cancer disease. It exploits the unique electrical properties of this TFET for sensitive detection of both tumorigenic and non-tumorigenic cells. Featuring an inverted C-shaped tunnel junction with overlapped source pocket, and nanocavities, the biosensor shows enhanced detection sensitivity of TFET based biosensor with high precision. Analysis of electrostatic properties and dielectric constant variation of breast cancerous cell lines elucidates the detection mechanism. Evaluation of sensitivity parameters highlights the effectiveness of the biosensor, especially with optimized cavity structures. This biosensor offers promise for array-based breast cancer screening, with advantages including simplified transduction, cost-effectiveness, and compatibility with CMOS processes, contributing to improved patient outcomes in oncology.</p>