The current method of obtaining a diagnosis for cancer is by histopathological evidence from a tissue sample obtained by biopsy, which is then examined under a microscope.

The biopsy procedure is often supported by the use of imaging techniques such as magnetic resonance imaging (MRI) or a computed tomography (CT) scan. However, the evolution of various techniques and platforms with applications in cancer diagnosis and prognosis appear to offer promising alternatives.

One such technique is liquid biopsy, which uses circulating tumour cells (CTC) to predict the survival of patients with different types of cancer. CellSearch, the first US Food and Drug Administration (FDA) approved diagnostic device for detecting CTCs in cancer patients with metastatic breast, prostate, or colorectal cancer, separates and enumerates these CTCs, which can then be used as a prognosis tool to predict the survival of these patients. The test is blood-based and aids in the assessment of prognosis in patients with cancer.

"PAMMOTH emits pulses of light toward the tumor that, when absorbed, are converted into thermal energy."

Other platforms are also being developed for similar applications. A group of researchers from the University of Twente in the Netherlands is developing a system that works on the photoacoustic technique and is intended to be used for diagnosis of breast cancer (University of Twente, 2016). The system is called PAMMOTH and it emits pulses of light toward a tumour that, when absorbed, is converted into thermal energy. This leads to thermal expansion, which causes the formation of a pressure wave. With the help of ultrasound detectors, the input signal (specifically, the pressure waves) can be used to create a three-dimensional (3D) map to indicate the presence of tumour vasculature inside the breast.

Another approach being developed is a handheld fiber optic probe intended for multimodal biological imaging. It incorporates a multicore imaging fiber, which is currently being worked on by a team of researchers in Germany (Lukic et al., 2017). If developed successfully, such a probe would enable the diagnosis of cancerous cells by endoscopy methods.

Advances in genomic sequencing and optical imaging have propelled the development of these devices, which appear promising for applications such as cancer diagnosis. Once these platforms are fully developed, tested for efficiency, and established as a viable alternative to the current approach, it is possible that biopsies could become a practice of the past.