Researchers in the United States have developed a new and non-invasive method to produce a biopsy for skin cancer.
The number of people with skin cancer is increasing around the world. For example, in the United States, it is estimated that there will be 125 million people aged 55 to 85 by 2050, with approximately 20% of these people developing skin cancer before they reach 70.
Over the past decades, the occurrence of skin cancer has only increased. Globally, one in every three new cancer diagnoses is skin cancer, amounting to 2-3 million non-melanoma skin cancers and 132,000 melanoma skin cancers every year.
Therefore, it is imperative that skin lesions (i.e., any skin abnormality) be diagnosed as quickly as possible. However, often the only way to diagnose a skin lesion is to perform a surgical biopsy, which may result in scarring. In some cases, doctors who perform biopsies often do not even know if their procedure will be adequate, as they may not know the size of the lesion before starting. If the lesion is too large, the biopsy cannot be completed, and the patient will have to be referred to a specialist for more extensive tissue removal, which may then require post-operation plastic surgery.
Vibrational Optical Coherence Tomography (VOCT)
Researchers from Rutgers University have developed a new diagnostic technique known as vibrational optical coherence tomography (VOCT). This new method uses a combination of near infrared light and sound vibrations, applied transversely (i.e., perpendicularly) to the suspected lesion area, to produce a “virtual biopsy” quickly and painlessly. Specifically, laser diode light creates a three-dimensional image of the lesion to determine its size and shape, while the soundwaves (via an inch-long speaker) determine the lesion’s stiffness and density. This latter part is important, as tumours and cancer cells are typically stiffer than neighbouring normal tissue.
VOCT capable of discerning between cancerous and normal tissue
The researchers evaluated VOCT for a six-month trial period. Four skin excisions (i.e., the removal of a skin tumour along with some of the surrounding tissue) were examined, and VOCT was also used to examine a group of eight volunteers who did not have skin lesions.
During this trial, VOCT was able to discern between cancerous tissue and healthy tissue, providing preliminary evidence that VOCT shows promise as a non-invasive method for producing a biopsy for skin cancer.
With additional trials and improvements, VOCT, which is currently awaiting FDA approval for a larger-scale trial, has the potential to transform the biopsy process for skin cancer patients. A surgical procedure that patients would understandably be wary of could be turned into a simple 15-minute event that could be performed at a doctor’s office.
Written by Raymond Quan, MASc, MBA
Silver et al. “Comparative ‘virtual biopsies’ of normal skin and skin lesions using vibrational optical coherence tomography.” Skin Res Technol. 2019;00:1–7. https://doi.org/10.1111/srt.12712
Press release: https://www.eurekalert.org/pub_releases/2019-06/ru-rsc061319.php
Skin biopsy fact sheet. MayoClinic. Available at: https://www.mayoclinic.org/tests-procedures/skin-biopsy/about/pac-20384634
Skin cancer fact sheet. WHO. Available at: https://www.who.int/uv/faq/skincancer/en/index1.html